Title of Invention	A PROCESS FOR THE EXTRACTION OF DIETARY FIBRE, OLERESIN, AND FIXED OILS FROM THE SEEDS OF FENUGREEK(TRIGONELLA FOENUM GRAECUM AND AN EXTRACTION MODULE APPARATUS FOR CARRYING OUT THE SAME
Abstract	A process for the extraction of dietary fiber, oleoresin and fixed oils from Fenugreek seeds is described wherein the seeds are extracted(reated) in two stages of extraction by freshly condensed solvents at nearly the condensing temperature thereof. The extraction apparatus comprises an extraction vessel, a reboiler and a condenser wherein the seed matter is contacted with freshly condensed solvent throughout the extraction. Evaporation of solvents from the extracts yields Fixed oils in the first stage and a mixture of fixed oils and oleoresin in the second. A low temperature procedure is used to separate the fixed oils from the oleoresin. The residue after the second stage of extraction is high purity food grade dietary fiber with fat content not exceeding 0.1% The preferred solvents are Petroleum Ether(40-60) for first s(age and 90-95% ethanol for the second. A food supplement/additive comprising from 30% to 85% dietary fiber, from 5% to 10'% of guar gum and up to 5% Oat Bran has been formulated.

Title of Invention

A PROCESS FOR THE EXTRACTION OF DIETARY FIBRE, OLERESIN, AND FIXED OILS FROM THE SEEDS OF FENUGREEK(TRIGONELLA FOENUM GRAECUM AND AN EXTRACTION MODULE APPARATUS FOR CARRYING OUT THE SAME

Abstract

A process for the extraction of dietary fiber, oleoresin and fixed oils from Fenugreek seeds is described wherein the seeds are extracted(reated) in two stages of extraction by freshly condensed solvents at nearly the condensing temperature thereof. The extraction apparatus comprises an extraction vessel, a reboiler and a condenser wherein the seed matter is contacted with freshly condensed solvent throughout the extraction. Evaporation of solvents from the extracts yields Fixed oils in the first stage and a mixture of fixed oils and oleoresin in the second. A low temperature procedure is used to separate the fixed oils from the oleoresin. The residue after the second stage of extraction is high purity food grade dietary fiber with fat content not exceeding 0.1% The preferred solvents are Petroleum Ether(40-60) for first s(age and 90-95% ethanol for the second. A food supplement/additive comprising from 30% to 85% dietary fiber, from 5% to 10'% of guar gum and up to 5% Oat Bran has been formulated.

Full Text	This invention relates generally to a process of extraction of Dietary Fibre, Oleoresin and Fixed Oils from the seeds of Fenugreek(Trigonella Foenum Graecum). More particularly, the invention relates to a process for the production of substantially pure food grade dietary fibre and other products from Fenugreek seeds. In this specification, the term "extraction' refers, depending on the context, to either the unit operation of extraction wherein a liquid solvent is brought into contact with a solid material with the object of dissolving(leaching out) one or more components thereof, or a process having said extraction operation as one of the steps thereof. Fenugreek is a herbaceous plant native to Western Asia from where it has spread widely over Europe, the Mediterranean and Asia. Both the leaves and the seeds of the plant are of economic significance as the leaves are widely used as a vegetable in some countries and the seeds, both ripe and unripe have several uses. The unripe seeds are also used as a vegetable while the ripe seeds are an important spice and condiment. Fenugreek seeds also have numerous traditional medicinal applications. A typical analysis of Fenugreek seeds is as follows: Percent Moisture 9.0 Ash 3.2 Lipids 7,0 Protein(Nx6.25) 26.0 Starch 1.6 Fibre 48.0 Mucilage 20.0 Hemicellulose 17.3 Cellulose 8.2 Lignin 2.5 Saponins 4.8 Trigonelline 0.37 Source: The Wealth of India, CSIR, Govt, of India Publication The lipids in Fenugreek seeds are the fixed oils thereof and compose fatty acids: palmitic, stearic, arachidic, behenic, oleic, linoleic and linolenic. As some of these constituents are of drying type the fixed oils of Fenugreek possess drying properties but there appears to be no known amplications thereof in this respect. Further the fixed oils of Fenugreek contain a factor which increases lactation in humans and cattle and furthermore contain saponins which are the precursors in the manufacture of some sterodic drugs. The fixed oils of Fenugreek are therefore an important commercial fraction thereof Oleoresin is another commercially important fraction of Fenugreek and comprises the flavouring and taste factors contained in Fenugreek. Oleoresin of Fenugreek has numerous applications in Food, Beverage, Dairy, Bakery and other industries where it is added for its taste, flavour, preservative and other characteristics. Dietary Fibre is another important fraction of Fenugreek which is particularly rich in both soluble and insoluble dietary fibre. Fenugreek is also rich in proteins and in this respect is on par with soyabean. In fact, from the point of view of the distribution of said amino acids, Fenugreek has an edge over soyabean. When oleoresin and fixed oils have been extracted out of Fenugreek seeds the protein content thereof passes into the seed residue which then is a good source of both the dietary fibres and proteins. In addition, the vitamins and minerals contained in the seed also substantially pass into the seed residue. Said residue is referred in the industry as the dietary fibre of fenugreek and as would be observed constitutes an excellent source of soluble and insoluble dietary fibre and the nutritional factors mentioned hereinabove. Thus, dietary fibre of fenugreek can be an important starting point for formulating substantially comprehensive food supplements and food additives. It will therefore be noted that Oleoresin, Fixed oils and Dietary Fibre are all commercially very significant fractions of fenugreek. This invention therefore, provides for extraction of these fractions from Fenugreek and also for formulations of the latter with other important nutritional factors such as guar gum which is a very good source of soluble fibre and oat bran which is another similar source for both soluble and insoluble fibre. Prior art processes of extraction of Fenugreek comprise U.S. Patent No. 5,658,571 for Preparation of the Debitterised Powder of the Seed of Plant Fenugreek' and U. S. Patent No. 5,997,877 on the ';Method of Extraction of Commercially Valuable Fractions of Fenugreek'. In U.S. 5,658,571 the solid material is loaded into a vessel and soaked in the solvent. During said soaking heat is provided to the material indirectly by steam passing through the vessel jacket. The process specifies solvents such as Ethylene Chloride, Methylene Chloride and Methanol. It is the observation of the present inventors that in such jacketted systems temperature does not remain uniform through the bed or over a period of time or both. Such temperature disuniformities apart from prolonging the required period of extraction also adversely affect the quality of the extract and the consistency thereof In U. S, 5,997, 877 a stirred/agitated tank is used for the extractioil operatioa The method of heating is not mentioned but it would appear that the heating is by steam jacket or other indirect means. The solvents used in the preferred embodiments are either aqueous ethanol or aqueous ethanol and water. Furthermore, tempering of the seeds is done prior to crushing/milling/flaking thereof which involves treating said seeds with water to enhance the moisture content thereof to about 14-22%. The present inventors are of the view that water adversely affects the quality of the dietary fibre product of Fenugreek seeds. Water affects the fixed oils contained in Fenugreek seeds and the rancidity produced leads to discolouration of the dietary fibre produce and to development of disagreeable odours This is also confirmed by U. S. 5,658, 571 where the inventors observe that dark brown to black discolouration of the dietary fibre is produced by water coming into contact with the seeds. The discolouration and odours make the dietary fibre unsuitable as a food supplement and additive. It is the object of the invention to remove the abovementioned drawbacks of temperature disuniformities and to prevent contact of the seeds with water. In extraction, a liquid solvent is made to contact a bed of the material to be extracted Initially, the driving force for extraction is high but as the solvent picks up more of the solute(s) from the solid said driving force comes down and the dissolution of the solute becomes slower and slower. It will be observed that said period of extraction(extraction time) has considerable impact on plant operation, plant capacity and on the capital and operating costs. Another object of this invention is to minimise the extraction process time i.e. the contact time between the solvents and solids. One way to counter the slow phase of an extraction process is to terminate the extraction at a certain point, drain the extract and charge the partly extracted bed with either fresh solvent or a solvent containing a lesser concentration of the solute than said extract. In this manner, overall extraction times are brought down and sometimes more than two such solvent streams are used. However, this approach leads to more tankage, pumping systems and lines etc. A yet another object of the invention is to locate a pair(s) or solvents for a two stage extraction of Fenugreek seeds such as to provide a very simple and economical process and where the separation and purification steps for said fractions are minimised. Thus the problems and considerations before the present inventors were: i. temperature disuniformities; ii. avoiding contact with water, and iii. minimising extraction time(contact time). This invention has taken care of all these in a novel way. In the process of the invention, the bed of solids to be extracted is brought into contact with substantially freshly condensed solvent at substantially the condensing temperature(boiling point) thereof. Thus, the present process provides for extraction of Fenugreek seeds, which may be unextracted or partly extracted of which may have been previously treated by operations such as cleaning, crushing, grinding, milling, sorting, or others necessary, by contacting a bed of said seeds with a substantially freshly condensed solvent(or mixture). Said freshly condensed solvent collects in the bed till said bed becomes partly or fully submerged and when the liquid reaches a certain pre-determined level said solvent(extract) is drained out. However, the process of charging said freshly condensed solvent into the bed continues and is followed by next said draining operation and so on. The various drainings that is, extracts return to a reboiler wherefrom said solvent is re-evaporated such as to provide continuous charging of said substantially freshly condensed solvent to the seed bed. It will be observed, therefore, that the central(and novel) features of the process of the invention are: i. the heat input to the bed to be extracted is in situ, that is, right at the surface of the material where the extraction occurs: ii. the bed is continuously contacted with said substantially freshly condensed solvent during substantially the entire period of extraction; iii. the extraction can be carried out at the highest feasible temperatures which can be as high as substantially the boiling point of the solvent. In any process of prior art, extraction at higher temperatures would create the problem of substantial solvent vapourisation and the solvent vapours would have to be handled and solvent recovered adding to the complexity and costs of the process. Whereas in the present process, carrying out extractions at or near the boiling point is simply and easily done with no such consequences as mentioned. This is because the solvent in the present process moves round in a closed cycle within a totally enclosed loop and does not come into contact with the atmosphere. Two further features of the process of the invention are elaborated hereinbelow: Firstly, as mentioned hereinabove, halogenated solvents and methanol have been specified in the prior art processes but no mention is found therein about the method employed to eliminate the solvent traces to give a food grade product. This invention considers the problem of removal of said solvent traces quite expensive and somewhat intractable. This process has therefore been adapted to avoid the use of said problematic solvents. Secondly, the frequency(number) of said draining operations(of the solvent from the bed) is such that said bed is contacted almost continuously with substantially fresh solvent so as to ensure that said driving force of extraction remains close to the maximum value thereof over substantially the whole of said contact time. For the purposes of this invention, the major components of Fenugreek seeds are: Cleoresin, Fixed Oils and Dietary Fibre. These also happen to be the commercially significant fractions and therefore another object of this invention is to fractionate Fenugreek seeds such as to obtain said fractions in substantially pure form, that is, of a purity level acceptable in food applications. Most solvents extract a mixture of said fractions. However, some solvents are selective in their action and may extract one said component at a more rapid rate than another or others. Also, a solvent may extract just one said fraction only. The object of this invention was therefore to locate a pair of solvents for a two-stage extraction of Fenugreek seeds such as to provide a very simple and economical process and where the separation and purification steps for said fractions are minimised. It may be noted that the process of the invention would certainly appear to be more simple and economical than the two cited prior art processes and perhaps may remain as the best and most economical process for substantially pure and food grade fibre, oleoresin and fixed oils for some time to come. It must be mentioned that the two said U. S. patent processes have not indicated the final product purity obtained therein. Thus, this process provides for said extraction of Fenugreek seeds separately by two solvents(or mixtures) in two stages and comprises a first stage extraction with a first solvent(or mixture) and a second stage extraction by a second solvent(or mixture) said seeds having undergone one or more prior treatment steps if necessary, such as cleaning, sorting, crushing, grinding, milling or others. The two stages respectively yield the first and second extracts. It was the further object of this invention to select said first solvent(s) such as to extract out as much of said fixed oils as possible during said first stage preferably without any other fraction being extracted therewith. Most solvents simultaneously extract said oleoresin and fixed oil fractions. Therefore, the location(discovery) by this invention of solvent(s) the action of which is selective in reference to fixed oils is novel and has some very useful consequences. Said useful consequences are: i. it ensures that said first extract is a pure fraction, namely, fixed oil so that substantially no further treatment thereof is necessary apart from evaporation of the solvent contained in said first extract ii. it ensures that said second extract contains much less of said fixed oils than otherwise and this simplifies and minimises the subsequent processing and costs thereof iii. the extraction of the bulk of said fixed oil fraction in the first stage minimises, or substantially eliminates the possibility of said discolouration or odour formation caused by the contact of the seed material with water. Thus, this process allows for the use of even aqueous solvents, for example in said second stage. Said first solvents provided in this invention are Petroleum Ether, Hexane, n-Propanol and iso-Propanol and said second solvents are Ethyl Alcohol, Isoprqpyl Alcohol and aqueous ethanols of various concentrations. The solvents for a stage would be any individual member of the relevant group or mixtures thereof within the scope of the invention Said solvents of the invention comprising said first and second solvents(or mixtures) provide between 75% to 85% extraction of said fixed oil in said first stage and substantially the whole of the remainder of the fixed oils in said second stage. Oleoresin is extracted in said second stage and substantially the whole of it is extracted out in the second stage. Therefore, as far as said first extract is concerned when the solvent is evaporated out therefrom by simple distillation a pure said fixed oil fraction is obtained. This fixed oil fraction does not require any further treatment. Said second extract contains: i. substantially the whole of the oleoresin fraction contained in the seeds: and ii. substantially the whole of said remainder of the fixed oil fraction left in the seeds after said first extraction This process provides for the evaporation of the solvent from said second extract and subsequent separation of said oleoresin fraction and fixed oils. Unlike as in the prior art in processes, the evaporating off of the solvents contained in said first and second extracts has substantially no cost implications because said solvents require to be evaporated so as to produce their vapours which are then condensed and applied to the seed material in the extraction stages. In fact, in the process of the invention the evaporation of the solvents from said first and second extracts is carried out in the respective reboilers of said stages. For separation of said remainder fixed oil from the oleoresin this process provides a low temperature procedure. As mentioned hereinabove, for extraction in said first and second stages the invention requires that the respective solid materials be contacted with, and partly or fully submerged in their respective solvents which must be in substantially freshly condensed form Also said solvents must be substantially at their respective condensing temperatures. To provide for said contact under the conditions mentioned hereinabove, this invention provides for a novel extraction module which comprises: i. an extraction vessel having means for holding said bed of solid materials to be extracted; ii reboiler; and iii. a condenser. interconnected such as to evaporate said solvent(s) in said reboiler, condense the vapours thereof in said condenser and apply(contact) the condensed solvent to said solid materials contained in said vessel. Said module is provided with suitable control means such as to: i. periodically drain the solvent from the bed; ii. periodically withdraw samples of the extract; iii. regulate the heat input and coolant to the reboiler and condenser respectively; and iv. for any other required control. Within the scope of the invention the heating means for said reboiler may be steam or other. Further within the scope of the invention a said module may be used for both said stages or alternatively two modules may be used one each for each of the said two stages. As mentioned hereinabove, the condensed solvent collects in said vessel and when the level thereof reaches a predetermined value said extract is drained out into said reboiler. In this process the frequency(number) of said drainings has been kept high so as to make the extraction process almost continuous, that is, semi-continuous the object being to keep said driving force high. The scope of the invention also covers said other frequencies and also continuous contacting and draining. Thus, this invention provides for a process of extraction of Fenugreek seeds, the products produced by the process, namely, Oleoresin, Fixed oils and the Dietary Fibre and further an Extraction Module for carrying out said extraction of Fenugreek seeds. Still further the invention provides for a formulation comprising said dietary fibre, a bran and guar gum The said formulation may further have one or more colouring and/or flavouring agents and vitamins and/or minerals. According to the invention, therefore, there is provided a process for the extraction of dietary fibre, oleoresin and fixed oils from the seeds of Fenugreek(Trigonella Foenum Graecum) comprising: optionally cleaning of said fenugreek seeds, and sorting, crushing, grinding and/or milling thereof; treating the said seeds with a substantially freshly condensed first solvent such as herein described in a first stage of extraction to yield a first extract and partly treated seeds; said first extract containing at least 75% of the fixed oils originally contained in said seeds together with the said solvent; further treating of the said partly treated seeds with a substantially freshly condensed second solvent such as herein described in a second stage of extraction to yield a second extract and said substantially pure wet dietary fibre, said second extract containing said oleoresin and substantially the whole of the remainder of said fixed oils contained in said partly treated seeds and said second solvent; drying of said substantially pure dietary fibre by heating upto temperatures between 80-100oC; heating said first extract to temperatures below the boiling point of the said first solvent so as to evaporate said first solvent therein to isolate said substantially pure fixed oils such as herein described; heatingg said second extract to temperatures below tne boiling point or me said second solvent to evaporate said second solvent therein to isolate a product mixture containing said oleoresin and substantially the whole of the remainder of said fixed oils contained in said partly treated seeds; treating said product mixture obtained in step (vi) with ethanol for a period of time and at a temperature as herein described; cooling said treated product mixture to a temperature ranging from -10° C to -15° C obtain a heavy phase and a light phase; separating said heavy and light phases, preferably by decanting, said separated heavy phase comprising said substantially pure oleoresin; separating the crystallised impurities if any, such as fats and waxes from said light phase preferably by filtering; and evaporating ethanol from said light phase preferably by heating, to yield said substantially pure fixed oils. Further, according to another feature of this invention, there is provided: a. a substantially pure dietary fibre of Fenugreek seed produced by the process of the invention; b. a substantially pure oleoresin of Fenugreek seed produced by the process of the invention; c. a substantially pure fixed oils of Fenugreek seed produced by the process of the invention. Thus, according to the invention, there is further provided an extraction module apparatus for carrying out said process for the extraction of Dietary Fibre, Oleoresin and Fixed Oils from Fenugreek seeds comprising: i. an extractor vessel having means for holding said bed of solid materials to be extracted; ii. a reboiler; and iii. a condenser, interconnected such as to provide evaporation of said solvent in said reboiler, condensation of the vapours thereof in said condenser, contacting of said substantially freshly condensed solvent with said bed at substantially the condensing temperature thereof, and further comprising the necessary means for periodically draining said first and second extracts and for controlling heat input to said reboiler and other control means necessary. According to a still further feature of the invention there is provided a formulation useful as a fibrous food supplement or as an edible food additive, comprising: i. the dietary fibre of Fenugreek seed, produced by the process of the invention; ii. one or more brands such as of wheat, oats or others, iii. guar gum, and iv. one or more vitamins and/or minerals, and further comprising, as required, one or more colouring and/or flavouring agents. The raw material for the process of the invention is Fenugreek seeds. Said seeds may be virgin(unextracted) or they may have undergone a previous extraction(s). Also, the seeds charged into extractor may have had one or more prior treatments such as grading, sorting, cleaning, crushing, grinding , milling or others. All these options are within the scope of the invention. The seeds could have undergone any other treatment prior to feeding to the extractor. The process of the invention is easily and singly adapted for any feed size from raw seeds to milled flour of fenugreek. Preferably, however, the size of the feed material is reduced by crushing or grinding of the seeds to facilitate said contact and reduce said contact time. More preferably, the size of the seed particles for feeding to the extraction vessels is -60 tol90 B.S.S. Seeds crushed to this size are fed to said first stage in the preferred embodiment and after said first extraction are fed to the second stage. Further size reduction may be done before feeding to second stage if desired. But in the preferred embodiment no further size reduction is carried out for said second stage. The various alternatives outlined are within the scope of the invention. There are a large number of solvents( and mixtures) that may be used for said extractions. Preferably, the solvents for the first stage are Petroleum Ether, Hexane, n-propanol and iso-propanol or mixtures thereof and for said second stage are ethanol, iso-propanol and aqueous ethanols and mixtures thereof More preferably, the solvent for the first stage is Petroleum Ether(40-60) and for the second stage is 90-95% ethanol so as to obtain full advantage of the process of the invention Preferably for said second stage aqueous ethanols of strength ranging from 94% to 100%(absolute alcohol) are employed. The process of the invention is flexible in this respect and the choice of concentration can be made taking into account factors such as availability, economics and convenience. More preferably, the solvent for second stage is 95% ethanol as in the preferred embodiment. These variations are within the scope of the inventioa A solvent mixture comprising any one or more of the members of the solvent group(for a stage) may be used. In the selection of the components of mixtures cost, availability and convenience factors may also be taken into consideration to optimise the selection. ied out at any temperature from ambient substantially to the boiling of the respective solvent. Preferably, the extraction is carried out at substantially the condensing temperature(boiling point) of the solvent but extractions at other temperatures are within the scope of the invention. For the solvents selected in the preferred embodiment, extraction is carried out at the maximum practicable temperature so as to minimise said extraction(contact) time. The operating temperatures in the preferred embodiment are 50°C to 60 C in the first stage and 78° C to 82° C in the second stage. The contact ratio, that is, the ratio of the weight of the material to be extracted(kgs) to the total volume (litres) of solvent contacted therewith in a stage ranges from 1:1 to about 1:10 and even higher. A higher value coupled with a faster boiling rate in the reboiler has the effect of bringing down said contact time. A higher contact ratio also means higher energy costs of boiling the solvent. The contact ratios in the preferred embodiment have been chosen after balancing these factors. The contact ratios provided by the invention in the preferred embodiment are from 1:1 to 1:5 for the first stage and 1:1 to 1:7 for the second stage. Drying the dietary fibre product is preferably carried out in a drier heated by steam. The jacket is used for both heating by steam and cooling by water. The process is simply adapted to other driers such as tray, fluidised bed, rotary and others. In the preferred embodiment the diying time was about one hour during which the solvent adhering to the solids is evaporated and moisture brought down to about 3% to 5%. The dried dietary fibre product is then cooled in said and then sent for packing. The said first extract which comprises the fixed oils and solvent is heated in the reboiler to remove the solvent yielding solvent free fixed oils product which is then sent for packing. Other methods of solvent removal may be used within the scope of the invention. Said second extract which comprises: i. said subtantially all of the remainder of fixed oils: ii. substantially all of the oleoresin contained in the seeds: iii. 90-95% ethanol solvent: and iv. fat and wax inpurities, is also heated in the reboiler to evaporate off substantially all of the solvent. The solvent free second extract is then heated in a stirred, jacketted vessel to 110° C so as to remove residual solvent and moisture yielding said product mixture comprising substantially pure oleoresin and fixed oils. The heating of said solvent free second extract is carried out in a jacketted vessel having provision for heating by steam and cooling by water. The jacketted vessel is provided with paddle and propeller type agitators the former being provided for scraping the oleoresin off the vessel surfaces. After the solvent traces have been evaporated the product mixture is cooled to 40°C to SO C by circulating water in the jacket. Other types of vessels, agitators and heating and cooling means are usable and are within the scope of the invention. After cooling of said product mixture it is treated with 98% ethanol and the material is maintained at about 30 C by slow heating with steam. Said extraction module comprises a vessel of stainless steel or other materials and is generally of circular cross section. However, within the scope of the invention, the vessel may be of other shape or cross section. The holding means for said bed(of seed material) may be a perforated plate of suitably sized perforations with or without a filtering medium such as cloth or other material. Alternatively, as in the preferrred embodiment, said holding means could be a wire mesh stainless steel basket. The preferred arrangement comprises one module for each stage. Other arrangements such as one module serving both stages or more than one module serving a stage are within the scope of the invention. The reboiler in the preferred embodiment comprises a generally cylindrical vessel provided with steam coils but other types of reboilers would be within the scope of the inventioa In the process of the invention, the solvent from said first and second extracts is evaporated in their respective rollers. However, other methods of desolventising are within the scope of the invention. The final solvent traces are removed in other equipment such as a steam jacketted pans or other vessels. Said condense in the module comprises an overhead tubular condenser provided with cooling water circulation. The condenser is located directly above the vessel to ensure the shortest path for said freshly condensed solvent to the extraction vessel. Distributor means are provided, if required, to ensure proper and uniform distribution of the condensed solvent over the whole vessel cross-section. In the preferred embodiment the condenser body is of carbon steel and the tube bundle of stainless steel Interconnected piping is provided for the solvent cycle, that is, vapourisation from reboiler, flow to said comdenser and condensation therein, entry into said vessel and draining firom said vessel to said reboiler. The drain line is provided with a sampling outlet wherefrom samples of said extract(s) are withdrawn periodically for indication of the solute content, that is, of the progress of the extraction. The heat input to the reboiler, determines the rate of evaporation of the solvent and therefore, the rate of charging of said freshly condensed solvent to the extraction bed. As mentioned hereinbefore, said freshly condensed solvent collects in the seed bed and when the level thereof reaches the pre-determined level the collected solvent is drained into the reboiler. The time from one said draining to the next is referred to the cycle time. A low cycle time implies a high throughput of the solvent, that is, a high rate of heat input whereas a high cycle time means that the solvent remains in contact in the bed somewhat longer during which said driving force tends to drop. Considering these factors, this invention provides that preferably said cycle times are from 15 minutes to 35 minutes. More preferably, the cycle times are bom 20 minutes to 30 minutes as in the preferred embodiment described further hereinbelow. Approximately, five minutes of each cycle tim represents the draining time and the rest the time during which the solvent collects in the bed. Any method of conveying said seed material from and to said modules is within the scope of the invention. Preferably, however, (pneumatic means are employed as in the embodiments described Thus, in the preferred embodiment handling of the solid matter is entirely by pneumatic means which helps in preventing ingress of impurities in the food grade products of the process. Said product mixture after the treatment with 98% ethanol is transferred to another agitated vessel where chilled brine is circulated in the jacket thereof to reduce the temperature down to -10 C to -15 C. At this point, said prooduct mixture separates out into: i. a heavy phase comprising substantially pure oleoresin; ii, a light phase comprising substantially pure fixed oils along with the 98% ethanol; and iii. a small quantity of precipitated solid fat and wax matter. Separation of said heavy phase bom the remainder is carried out by any known means such as decanting, filtration or others. The separated heavy phase is substantially pure oleoresin product. The hot phase is also sutgected to separation by any one of known means to remove said fat and wax matter if any, lexnaining. The 98% ethanol used for treating said product mixture and remaining in said light base is evaporated off to give the product, namely, substantially {Hire fixed oils. In order to provide a clearer understanding of the invention and without limitation to the scope of the invention two embodiments of the process of the invention will now be described in detail by way of example and further an embodiment of the extraction module apparatus of the invention will be described with reference to the accompanying drawing wherein Fig. 1 shows the Extraction Module Apparatus for carrying out the process of the invention. Example I: About 2 kgs. of healthy Fenugreek seeds were taken and cleaned to remove all extraneous matter such as dirt, waste etc. The seeds were then ground to -60 to + 90 B.S.S. The ground seeds were charged to the extractor of the first stage, that is, in said stainless steel wire mesh basket of the first extraction vessel. Petroleum Ether (40-60) was loaded into the reboiler. The vapour line from the reboiler has suitable regulating means to direct the solvent vapour either to the extractor or to outside such as to condensation and storage. The valves were adjusted to feed the vapour to the condenser from where the condensed vapour flowed into the seed bed. The solvent began to collect in the bed. A cycle time of about 25 minutes was used of which about 20 minutes was the time during which said solvent collected in the bed and reached said pre-determined level which was fixed a few centimetres above the top of said bed. The draining time was about five minutes. Six said cycles of extraction were carried out so that the total time of the extraction was about 1.5 hours. The extraction was carried at a temperature of 50 C to 55 C. The contact ratio over the whole extraction phase was about 1:2.5 to 1:3.5 (kg/litre). The seed material from the seed bed of the first stage was removed and dried to remove to residual solvent and then charged to second stage extraction module. The solvent was evaporated from the first extract and about 0.13 kg. of said substantially pure fixed oil product was obtained. About I kg. of the dried seed material obtained after first stage extraction was loaded into the second stage extraction module wherein the solvent was 95% ethanol. The same cycle time of 25 minutes was used and seven cycles were carried out the said overall extraction time being about three hours and the extraction carried out at a temperature of 78 C to 82 C. The contact ratio was about 1:2.5 to 1:3.5 weight/volume(kg71itre) Said substantially pure dietary fibre obtained irom the second stage was dried in a small drier to remove the solvent traces and to bring down the moisture content to about 5%. The analysis of the dietary fibre obtained was: Moisture 4.35% w/w Protein 43.06% w/w Fat Fibrous material 52.5% w/w The product obtained was of a very high purity and met all the requirements of a food grade product and more. In particular, attention is drawn to the extremely low fat content thereof. Solvent from said second extract was evaporated off in the second stage reboiler to yield said product mixture consisting of: i. substantially all of the oleoresin in the seeds; ii. substantially all of the fixed oils remaining in the seeds after first stage extraction; iii. fat and waxy impurities if any, and iv. residual solvent and moisture. Said product mixture was treated in a jacketted agitated vessel to about 111°C to evaporate the residual solvent and moisture and thereafter was cooled to about 40 °C. About 175 ml. Of 95% ethanol was added and the mixture stirred for about one hour during which the temperature was maintained at about 50° C. Said treated mixture was cooled to about -10 C to -15 C by keeping it in an ice-salt bath. The treated mixture separated into a light phase and a heavy phase. The heavy phase was decanted and comprised the oleoresin fraction, that is, substantially pure oleoresin. In a second embodiment, about 2 kgs. Fenugreek seeds after grinding to the size mentioned hereinabove were extracted in said first stage with n-hexane solvent. The contact ratio was about 1:3 w/v and the extraction was carried out at from 66 C to 71 C. The cycle time was about 25 minutes and the extraction was done for about 2.5 hours. After the extraction the seed material was dried to remove solvent and then charged to second stage extraction. Solvent was separated from the first extract by simple distillation and 0.003 kg. of fixed oil product was obtained, An apparatus to extract Dietary Fibre, fixed oils and Oleoresin from Fenugreek seeds is explained in the accompanying drawings. The rest of the extraction procedure was carried out as in the first embodiment. The extraction module apparatus shown in Fig. 1 comprises a vessel 1 of stainless steel of circular cross section. Said holding means for holding the solids to be extracted comprises a wire mesh basket 2 made of stainless steel. Said basket 2 sits on the bottom plate 3 that fonns the bottom of the extraction compartment wherein said freshly condensed solvent collects till it is drained into the reboiler. 4. Reboiler 4 comprises steam coils (5) heating the extract contained therein so as to evaporate the solvent therefrom. Drain line 6 allows periodical draining of the extract into reboiler 4. Solvent vapour flows through vapour line 7 into the vapour space above the wire basket 2. The solvent vapours rise into the condenser 8 and get cooled and condensed. Condenser 8 is of tubular type comprising tube bundle 9 of stainless steel. A vent 10 allows solvent vapours and other gases if any, to be vented to atmosphere when required. During operation the extract gets concentrated in reboiler 4 and when all the solvent is evaporated off the product remains. Said product is substantially pure fixed oils in case of stage 1 and a mixture of oleoresin and fixed oils in the case of stage 2 extraction. Said product can be removed through outlet 11. A door 12 is provided on one side of said vessel 1 for introduction of the seed material required to undergo extraction and for withdrawing extracted(treated) solid material such as the wet dietary fibre and said partly treated seeds. Said charging and withdrawal of material is done by means of a portable pneumatic conveying unit having hoses for the suction and discharge of the solid material. Said hoses may be introduced into the solids bed through said door 12. Provision is made in the interconnecting piping to move the solvent vapours to an outside condenser for condensation and storage of solvent when not required for the extraction process. Two such extraction module apparatus are used in the process one for the first stage extraction and the other for the second. Water is circulated in the condenser tubes to cool and condense the solvent vapours. In the drain line 6 an outlet is provided for periodical drawing of extract samples to measure the solute content. Embodiments and variations other than described are feasible by persons skilled in the art and are within the scope and spirit of the invention. We claim: 1. A process for the extraction of Dietary Fibre, Oleoresin and Fixed Oils from the seeds of Fenugreek(Trigonella Foenum Graecum) comprising: i. optionally cleaning of said fenugreek seeds, and sorting, crushing, grinding and/or milling thereof; ii. treating the said seeds with a substantially freshly condensed first solvent such as herein described in a first stage of extraction to yield a first extract and partly treated seeds; said first extract containing at least 75% of the fixed oils originally contained in said seeds together with the said solvent; iii. further treating of the said partly treated seeds with a substantially freshly condensed second solvent such as herein described in a second stage of extraction to yield a second extract and said substantially pure wet dietary fibre, said second extract containing said oleoresin said substantially the whole of the remainder of said fixed oils contained in said partly treated seeds and said second solvent; iv. drying of said substantially pure dietary fibre by heating upto temperatures between 80-100 °C; V. heating said first extract to temperatures below the boiling point of the said first solvent so as to evaporate said first solvent therein to isolate said substantially pure fixed oils such as herein described; vi. heating said second extract to temperatures below the boiling point of the said second solvent to evaporate said second solvent therein to isolate a product mixture containing said oleoresin and substantially the whole of the remainder of said fixed oils contained in said partly treated seeds; vii. treating said product mixture obtained in step (vi) with ethanol for a period of time and at a temperature as herein described; viii. cooling said treated product mixture to a temperature ranging from -10 °C to -15° C obtain a heavy phase and a light phase; ix. separating said heavy and light phases, preferably by decanting, said separated heavy phase comprising said substantially pure oleoresin; separating the crystallised impurities if any, such as fats and waxes from said light phase preferably by filtering; and evaporating ethanol from said light phase preferably by heating, to yield said substantially pure fixed oils. The process as claimed in preceding Claim 1 wherein said first solvent is selected from Petroleum Ether, Hexane, n-propanol and iso-propanol and said second solvent is selected from Ethanol, iso-propanol and aqueous ethanol. The process as claimed in the preceding Claim 2 wherein said first solvent is Petroleum Ether(40-60) and said second solvent is 90-95% ethanol. The process as claimed in the preceding claims wherein said first extraction is carried out at a temperature of 50 °C to 60 °C and said second at a temperature of 78 °C to 82° C. The process as claimed in the preceding claims wherein said seed material is of size -60 to +90 B.S.S. The process as claimed in the preceding claims wherein the ratio of the amount of said seed material to the amount of said solvent contacted in said first stage is 1:1 to 1:5 weight/volume(kg./litre) and in said second stage is 1:1 to 1:7 weight/volume(kg/litre). The process as claimed in the preceding claims wherein said overall contact time in said first extraction stage is about 1 to 2.5 hours and in said second extraction stage is about 2 to 4 hours. The process as claimed in the preceding claims wherein said frequency(number of times) of said drainings of said first and second extracts during extraction is 5 to 8 and 8 to 14 respectively. The process as claimed in any of the preceding claims wherein said product mixture is treated with 98% ethanol for a period of time of from 45 minutes to 90 minutes, said temperature ranging from 45 C to 55 C. The process as claimed in the preceding Claim 9 wherein the ratio of the amount of said product mixture to that of the amount of said 98% ethanol used for the treatment thereof is from 1:1 to 1:3. An extraction module apparatus for carrying out said process as claimed in Claim 1 comprising: i. an extractor vessel having means for holding said bed of solid materials to be extracted; ii. a reboiler; and iii. a condenser; interconnected such as to provide evaporation of said solvent in said reboiler, condensation of the vapours thereof in said condenser, contacting of said substantially freshly condensed solvent with said bed at upto substantially the condensing temperature thereof, and further comprising the necessary means for periodically draining said first and second extracts and for controlling heat input to said reboiler and other control means necessary. extraction module apparatus as claimed in the preceding Claim wherein said holding means comprise a wire mesh basket made of stainless steel The extraction module apparatus as claimed in any of the preceding Claims 11 and 12 wherein pneumatic conveying means are provided for charging material to, and discharging material from said vessel. A process for the extraction of Dietary Fibre, Oleoresin and Fixed Oils from the seeds of Fenugreek(Trigonella Foenum Graecum,) substantially as herein described. 15 An extraction module apparatus for carrying out said process as claimed in Claim 1, substantially as herein described and illustrated with reference to the accompanying drawing.

Full Text

This invention relates generally to a process of extraction of Dietary Fibre, Oleoresin and Fixed Oils from the seeds of Fenugreek(Trigonella Foenum Graecum). More particularly, the invention relates to a process for the production of substantially pure food grade dietary fibre and other products from Fenugreek seeds.
In this specification, the term "extraction' refers, depending on the context, to either the unit operation of extraction wherein a liquid solvent is brought into contact with a solid material with the object of dissolving(leaching out) one or more components thereof, or a process having said extraction operation as one of the steps thereof.
Fenugreek is a herbaceous plant native to Western Asia from where it has spread widely over Europe, the Mediterranean and Asia. Both the leaves and the seeds of the plant are of economic significance as the leaves are widely used as a vegetable in some countries and the seeds, both ripe and unripe have several uses. The unripe seeds are also used as a vegetable while the ripe seeds are an important spice and condiment. Fenugreek seeds also have numerous traditional medicinal applications.
A typical analysis of Fenugreek seeds is as follows:
Percent
Moisture 9.0
Ash 3.2
Lipids 7,0
Protein(Nx6.25) 26.0
Starch 1.6

Fibre 48.0
Mucilage 20.0
Hemicellulose 17.3
Cellulose 8.2
Lignin 2.5
Saponins 4.8
Trigonelline 0.37
Source: The Wealth of India, CSIR, Govt, of India Publication
The lipids in Fenugreek seeds are the fixed oils thereof and compose fatty acids: palmitic, stearic, arachidic, behenic, oleic, linoleic and linolenic. As some of these constituents are of drying type the fixed oils of Fenugreek possess drying properties but there appears to be no known amplications thereof in this respect. Further the fixed oils of Fenugreek contain a factor which increases lactation in humans and cattle and furthermore contain saponins which are the precursors in the manufacture of some sterodic drugs. The fixed oils of Fenugreek are therefore an important commercial fraction thereof
Oleoresin is another commercially important fraction of Fenugreek and comprises the flavouring and taste factors contained in Fenugreek. Oleoresin of Fenugreek has numerous applications in Food, Beverage, Dairy, Bakery and other industries where it is added for its taste, flavour, preservative and other characteristics.
Dietary Fibre is another important fraction of Fenugreek which is particularly rich in both soluble and insoluble dietary fibre. Fenugreek is also rich in proteins and in this respect is on par with soyabean. In fact, from the point of view of the distribution of said amino acids, Fenugreek has an

edge over soyabean. When oleoresin and fixed oils have been extracted out of Fenugreek seeds the protein content thereof passes into the seed residue which then is a good source of both the dietary fibres and proteins. In addition, the vitamins and minerals contained in the seed also substantially pass into the seed residue. Said residue is referred in the industry as the dietary fibre of fenugreek and as would be observed constitutes an excellent source of soluble and insoluble dietary fibre and the nutritional factors mentioned hereinabove. Thus, dietary fibre of fenugreek can be an important starting point for formulating substantially comprehensive food supplements and food additives.
It will therefore be noted that Oleoresin, Fixed oils and Dietary Fibre are all commercially very significant fractions of fenugreek. This invention therefore, provides for extraction of these fractions from Fenugreek and also for formulations of the latter with other important nutritional factors such as guar gum which is a very good source of soluble fibre and oat bran which is another similar source for both soluble and insoluble fibre.
Prior art processes of extraction of Fenugreek comprise U.S. Patent No. 5,658,571 for Preparation of the Debitterised Powder of the Seed of Plant Fenugreek' and U. S. Patent No. 5,997,877 on the ';Method of Extraction of Commercially Valuable Fractions of Fenugreek'.
In U.S. 5,658,571 the solid material is loaded into a vessel and soaked in the solvent. During said soaking heat is provided to the material indirectly by steam passing through the vessel jacket. The process specifies solvents such as Ethylene Chloride, Methylene Chloride and Methanol.
It is the observation of the present inventors that in such jacketted systems temperature does not remain uniform through the bed or over a period of time or both. Such temperature disuniformities apart from prolonging the required period of extraction also adversely affect the quality of the extract and the consistency thereof

In U. S, 5,997, 877 a stirred/agitated tank is used for the extractioil operatioa The method of heating is not mentioned but it would appear that the heating is by steam jacket or other indirect means. The solvents used in the preferred embodiments are either aqueous ethanol or aqueous ethanol and water. Furthermore, tempering of the seeds is done prior to crushing/milling/flaking thereof which involves treating said seeds with water to enhance the moisture content thereof to about 14-22%.
The present inventors are of the view that water adversely affects the quality of the dietary fibre product of Fenugreek seeds. Water affects the fixed oils contained in Fenugreek seeds and the rancidity produced leads to discolouration of the dietary fibre produce and to development of disagreeable odours This is also confirmed by U. S. 5,658, 571 where the inventors observe that dark brown to black discolouration of the dietary fibre is produced by water coming into contact with the seeds. The discolouration and odours make the dietary fibre unsuitable as a food supplement and additive.
It is the object of the invention to remove the abovementioned drawbacks of temperature disuniformities and to prevent contact of the seeds with water.
In extraction, a liquid solvent is made to contact a bed of the material to be extracted Initially, the driving force for extraction is high but as the solvent picks up more of the solute(s) from the solid said driving force comes down and the dissolution of the solute becomes slower and slower. It will be observed that said period of extraction(extraction time) has considerable impact on plant operation, plant capacity and on the capital and operating costs.
Another object of this invention is to minimise the extraction process time i.e. the contact time between the solvents and solids.

One way to counter the slow phase of an extraction process is to terminate the extraction at a certain point, drain the extract and charge the partly extracted bed with either fresh solvent or a solvent containing a lesser concentration of the solute than said extract. In this manner, overall extraction times are brought down and sometimes more than two such solvent streams are used. However, this approach leads to more tankage, pumping systems and lines etc.
A yet another object of the invention is to locate a pair(s) or solvents for a two stage extraction of Fenugreek seeds such as to provide a very simple and economical process and where the separation and purification steps for said fractions are minimised.
Thus the problems and considerations before the present inventors were:
i. temperature disuniformities;
ii. avoiding contact with water, and
iii. minimising extraction time(contact time).
This invention has taken care of all these in a novel way.
In the process of the invention, the bed of solids to be extracted is brought into contact with substantially freshly condensed solvent at substantially the condensing temperature(boiling point) thereof. Thus, the present process provides for extraction of Fenugreek seeds, which may be unextracted or partly extracted of which may have been previously treated by operations such as cleaning, crushing, grinding, milling, sorting, or others necessary, by contacting a bed of said seeds with a substantially freshly condensed solvent(or mixture).
Said freshly condensed solvent collects in the bed till said bed becomes partly or fully submerged and when the liquid reaches a certain pre-determined level said solvent(extract) is drained out.

However, the process of charging said freshly condensed solvent into the bed continues and is followed by next said draining operation and so on. The various drainings that is, extracts return to a reboiler wherefrom said solvent is re-evaporated such as to provide continuous charging of said substantially freshly condensed solvent to the seed bed.
It will be observed, therefore, that the central(and novel) features of the process of the invention are:
i. the heat input to the bed to be extracted is in situ, that is, right at the surface of the material
where the extraction occurs:
ii. the bed is continuously contacted with said substantially freshly condensed solvent during
substantially the entire period of extraction;
iii. the extraction can be carried out at the highest feasible temperatures which can be as high as
substantially the boiling point of the solvent.
In any process of prior art, extraction at higher temperatures would create the problem of substantial solvent vapourisation and the solvent vapours would have to be handled and solvent recovered adding to the complexity and costs of the process. Whereas in the present process, carrying out extractions at or near the boiling point is simply and easily done with no such consequences as mentioned. This is because the solvent in the present process moves round in a closed cycle within a totally enclosed loop and does not come into contact with the atmosphere.
Two further features of the process of the invention are elaborated hereinbelow:
Firstly, as mentioned hereinabove, halogenated solvents and methanol have been specified in the prior art
processes but no mention is found therein about the method employed to eliminate the

solvent traces to give a food grade product. This invention considers the problem of removal of said solvent traces quite expensive and somewhat intractable. This process has therefore been adapted to avoid the use of said problematic solvents.
Secondly, the frequency(number) of said draining operations(of the solvent from the bed) is such that said bed is contacted almost continuously with substantially fresh solvent so as to ensure that said driving force of extraction remains close to the maximum value thereof over substantially the whole of said contact time.
For the purposes of this invention, the major components of Fenugreek seeds are: Cleoresin, Fixed Oils and Dietary Fibre. These also happen to be the commercially significant fractions and therefore another object of this invention is to fractionate Fenugreek seeds such as to obtain said fractions in substantially pure form, that is, of a purity level acceptable in food applications.
Most solvents extract a mixture of said fractions. However, some solvents are selective in their action and may extract one said component at a more rapid rate than another or others. Also, a solvent may extract just one said fraction only. The object of this invention was therefore to locate a pair of solvents for a two-stage extraction of Fenugreek seeds such as to provide a very simple and economical process and where the separation and purification steps for said fractions are minimised. It may be noted that the process of the invention would certainly appear to be more simple and economical than the two cited prior art processes and perhaps may remain as the best and most economical process for substantially pure and food grade fibre, oleoresin and fixed oils for some time to come. It must be mentioned that the two said U. S. patent processes have not indicated the final product purity obtained therein.
Thus, this process provides for said extraction of Fenugreek seeds separately by two solvents(or mixtures) in two stages and comprises a first stage extraction with a first solvent(or mixture) and a

second stage extraction by a second solvent(or mixture) said seeds having undergone one or more prior treatment steps if necessary, such as cleaning, sorting, crushing, grinding, milling or others. The two stages respectively yield the first and second extracts.
It was the further object of this invention to select said first solvent(s) such as to extract out as much of said fixed oils as possible during said first stage preferably without any other fraction being extracted therewith. Most solvents simultaneously extract said oleoresin and fixed oil fractions. Therefore, the location(discovery) by this invention of solvent(s) the action of which is selective in reference to fixed oils is novel and has some very useful consequences. Said useful consequences are:
i. it ensures that said first extract is a pure fraction, namely, fixed oil so that substantially no
further treatment thereof is necessary apart from evaporation of the solvent contained in said first extract
ii. it ensures that said second extract contains much less of said fixed oils than otherwise and
this simplifies and minimises the subsequent processing and costs thereof
iii. the extraction of the bulk of said fixed oil fraction in the first stage minimises, or
substantially eliminates the possibility of said discolouration or odour formation caused by the contact of the seed material with water. Thus, this process allows for the use of even aqueous solvents, for example in said second stage.
Said first solvents provided in this invention are Petroleum Ether, Hexane, n-Propanol and iso-Propanol and said second solvents are Ethyl Alcohol, Isoprqpyl Alcohol and aqueous ethanols of various concentrations. The solvents for a stage would be any individual member of the relevant group or mixtures thereof within the scope of the invention

Said solvents of the invention comprising said first and second solvents(or mixtures) provide between 75% to 85% extraction of said fixed oil in said first stage and substantially the whole of the remainder of the fixed oils in said second stage. Oleoresin is extracted in said second stage and substantially the whole of it is extracted out in the second stage. Therefore, as far as said first extract is concerned when the solvent is evaporated out therefrom by simple distillation a pure said fixed oil fraction is obtained. This fixed oil fraction does not require any further treatment.
Said second extract contains:
i. substantially the whole of the oleoresin fraction contained in the seeds: and
ii. substantially the whole of said remainder of the fixed oil fraction left in the seeds after said
first extraction
This process provides for the evaporation of the solvent from said second extract and subsequent separation of said oleoresin fraction and fixed oils. Unlike as in the prior art in processes, the evaporating off of the solvents contained in said first and second extracts has substantially no cost implications because said solvents require to be evaporated so as to produce their vapours which are then condensed and applied to the seed material in the extraction stages. In fact, in the process of the invention the evaporation of the solvents from said first and second extracts is carried out in the respective reboilers of said stages.
For separation of said remainder fixed oil from the oleoresin this process provides a low temperature procedure.

As mentioned hereinabove, for extraction in said first and second stages the invention requires that the respective solid materials be contacted with, and partly or fully submerged in their respective solvents which must be in substantially freshly condensed form Also said solvents must be substantially at their respective condensing temperatures. To provide for said contact under the conditions mentioned hereinabove, this invention provides for a novel extraction module which comprises:
i. an extraction vessel having means for holding said bed of solid materials to be extracted;
ii reboiler; and
iii. a condenser.
interconnected such as to evaporate said solvent(s) in said reboiler, condense the vapours thereof in said condenser and apply(contact) the condensed solvent to said solid materials contained in said vessel. Said module is provided with suitable control means such as to:
i. periodically drain the solvent from the bed;
ii. periodically withdraw samples of the extract;
iii. regulate the heat input and coolant to the reboiler and condenser respectively; and
iv. for any other required control.
Within the scope of the invention the heating means for said reboiler may be steam or other.
Further within the scope of the invention a said module may be used for both said stages or alternatively two modules may be used one each for each of the said two stages.
As mentioned hereinabove, the condensed solvent collects in said vessel and when the level thereof reaches a predetermined value said extract is drained out into said reboiler. In this process the

frequency(number) of said drainings has been kept high so as to make the extraction process almost continuous, that is, semi-continuous the object being to keep said driving force high. The scope of the invention also covers said other frequencies and also continuous contacting and draining.
Thus, this invention provides for a process of extraction of Fenugreek seeds, the products produced by the process, namely, Oleoresin, Fixed oils and the Dietary Fibre and further an Extraction Module for carrying out said extraction of Fenugreek seeds. Still further the invention provides for a formulation comprising said dietary fibre, a bran and guar gum The said formulation may further have one or more colouring and/or flavouring agents and vitamins and/or minerals.
According to the invention, therefore, there is provided a process for the extraction of dietary fibre, oleoresin and fixed oils from the seeds of Fenugreek(Trigonella Foenum Graecum) comprising: optionally cleaning of said fenugreek seeds, and sorting, crushing, grinding and/or milling thereof; treating the said seeds with a substantially freshly condensed first solvent such as herein described in a first stage of extraction to yield a first extract and partly treated seeds; said first extract containing at least 75% of the fixed oils originally contained in said seeds together with the said solvent;
further treating of the said partly treated seeds with a substantially freshly condensed second solvent such as herein described in a second stage of extraction to yield a second extract and said substantially pure wet dietary fibre, said second extract containing said oleoresin and substantially the whole of the remainder of said fixed oils contained in said partly treated seeds and said second solvent;
drying of said substantially pure dietary fibre by heating upto temperatures between 80-100oC;
heating said first extract to temperatures below the boiling point of the said first solvent so as to evaporate said first solvent therein to isolate said substantially pure fixed oils such as herein described;

heatingg said second extract to temperatures below tne boiling point or me said
second solvent to evaporate said second solvent therein to isolate a product
mixture containing said oleoresin and substantially the whole of the remainder of
said fixed oils contained in said partly treated seeds;
treating said product mixture obtained in step (vi) with ethanol for a period of
time and at a temperature as herein described;
cooling said treated product mixture to a temperature ranging from -10° C to -15°
C obtain a heavy phase and a light phase;
separating said heavy and light phases, preferably by decanting, said separated
heavy phase comprising said substantially pure oleoresin;
separating the crystallised impurities if any, such as fats and waxes from said light
phase preferably by filtering; and
evaporating ethanol from said light phase preferably by heating, to yield said
substantially pure fixed oils.
Further, according to another feature of this invention, there is provided:
a. a substantially pure dietary fibre of Fenugreek seed produced by the process of the invention;
b. a substantially pure oleoresin of Fenugreek seed produced by the process of the invention;
c. a substantially pure fixed oils of Fenugreek seed produced by the process of the invention.

Thus, according to the invention, there is further provided an extraction module apparatus for carrying out said process for the extraction of Dietary Fibre, Oleoresin and Fixed Oils from Fenugreek seeds comprising:
i. an extractor vessel having means for holding said bed of solid materials to be extracted;
ii. a reboiler; and
iii. a condenser,
interconnected such as to provide evaporation of said solvent in said reboiler, condensation of the vapours
thereof in said condenser, contacting of said substantially freshly condensed solvent with said bed at
substantially the condensing temperature thereof, and further comprising the necessary means for
periodically draining said first and second extracts and for controlling heat input to said reboiler and other

control means necessary.
According to a still further feature of the invention there is provided a formulation useful as a fibrous food supplement or as an edible food additive, comprising:
i. the dietary fibre of Fenugreek seed, produced by the process of the invention;
ii. one or more brands such as of wheat, oats or others,
iii. guar gum, and
iv. one or more vitamins and/or minerals,
and further comprising, as required, one or more colouring and/or flavouring agents.
The raw material for the process of the invention is Fenugreek seeds. Said seeds may be virgin(unextracted) or they may have undergone a previous extraction(s). Also, the seeds charged into extractor may have had one or more prior treatments such as grading, sorting, cleaning, crushing, grinding , milling or others. All these options are within the scope of the invention. The seeds could have undergone any other treatment prior to feeding to the extractor.

The process of the invention is easily and singly adapted for any feed size from raw seeds to milled flour of fenugreek. Preferably, however, the size of the feed material is reduced by crushing or grinding of the seeds to facilitate said contact and reduce said contact time.
More preferably, the size of the seed particles for feeding to the extraction vessels is -60 tol90 B.S.S. Seeds crushed to this size are fed to said first stage in the preferred embodiment and after said first extraction are fed to the second stage. Further size reduction may be done before feeding to second stage if desired. But in the preferred embodiment no further size reduction is carried out for said second stage. The various alternatives outlined are within the scope of the invention.
There are a large number of solvents( and mixtures) that may be used for said extractions. Preferably, the solvents for the first stage are Petroleum Ether, Hexane, n-propanol and iso-propanol or mixtures thereof and for said second stage are ethanol, iso-propanol and aqueous ethanols and mixtures thereof More preferably, the solvent for the first stage is Petroleum Ether(40-60) and for the second stage is 90-95% ethanol so as to obtain full advantage of the process of the invention
Preferably for said second stage aqueous ethanols of strength ranging from 94% to 100%(absolute alcohol) are employed. The process of the invention is flexible in this respect and the choice of concentration can be made taking into account factors such as availability, economics and convenience. More preferably, the solvent for second stage is 95% ethanol as in the preferred embodiment. These variations are within the scope of the inventioa
A solvent mixture comprising any one or more of the members of the solvent group(for a stage) may be used. In the selection of the components of mixtures cost, availability and convenience factors may also be taken into consideration to optimise the selection.

ied out at any temperature from ambient substantially to the boiling of the respective solvent. Preferably, the extraction is carried out at substantially the condensing temperature(boiling point) of the solvent but extractions at other temperatures are within the scope of the invention. For the solvents selected in the preferred embodiment, extraction is carried out at the maximum practicable temperature so as to minimise said
extraction(contact) time. The operating temperatures in the preferred embodiment are 50°C to 60 C
in the first stage and 78° C to 82° C in the second stage.
The contact ratio, that is, the ratio of the weight of the material to be extracted(kgs) to the total volume (litres) of solvent contacted therewith in a stage ranges from 1:1 to about 1:10 and even higher. A higher value coupled with a faster boiling rate in the reboiler has the effect of bringing down said contact time. A higher contact ratio also means higher energy costs of boiling the solvent. The contact ratios in the preferred embodiment have been chosen after balancing these factors. The contact ratios provided by the invention in the preferred embodiment are from 1:1 to 1:5 for the first stage and 1:1 to 1:7 for the second stage.
Drying the dietary fibre product is preferably carried out in a drier heated by steam. The jacket is used for both heating by steam and cooling by water. The process is simply adapted to other driers such as tray, fluidised bed, rotary and others. In the preferred embodiment the diying time was about one hour during which the solvent adhering to the solids is evaporated and moisture brought down to about 3% to 5%. The dried dietary fibre product is then cooled in said and then sent for packing.
The said first extract which comprises the fixed oils and solvent is heated in the reboiler to remove the solvent yielding solvent free fixed oils product which is then sent for packing. Other methods of solvent removal may be used within the scope of the invention.

Said second extract which comprises:
i. said subtantially all of the remainder of fixed oils:
ii. substantially all of the oleoresin contained in the seeds:
iii. 90-95% ethanol solvent: and
iv. fat and wax inpurities,
is also heated in the reboiler to evaporate off substantially all of the solvent. The solvent free second
extract is then heated in a stirred, jacketted vessel to 110° C so as to remove residual solvent and
moisture yielding said product mixture comprising substantially pure oleoresin and fixed oils.
The heating of said solvent free second extract is carried out in a jacketted vessel having provision for heating by steam and cooling by water. The jacketted vessel is provided with paddle and propeller type agitators the former being provided for scraping the oleoresin off the vessel surfaces. After the solvent traces have been evaporated the product mixture is cooled to 40°C to SO C by circulating water in the jacket. Other types of vessels, agitators and heating and cooling means are usable and are within the scope of the invention.
After cooling of said product mixture it is treated with 98% ethanol and the material is maintained at about 30 C by slow heating with steam.
Said extraction module comprises a vessel of stainless steel or other materials and is generally of circular cross section. However, within the scope of the invention, the vessel may be of other shape or cross section. The holding means for said bed(of seed material) may be a perforated plate of suitably sized perforations with or without a filtering medium such as cloth or other material. Alternatively, as in the preferrred embodiment, said holding means could be a wire mesh stainless steel basket.

The preferred arrangement comprises one module for each stage. Other arrangements such as one module serving both stages or more than one module serving a stage are within the scope of the invention.
The reboiler in the preferred embodiment comprises a generally cylindrical vessel provided with steam coils but other types of reboilers would be within the scope of the inventioa In the process of the invention, the solvent from said first and second extracts is evaporated in their respective rollers. However, other methods of desolventising are within the scope of the invention. The final solvent traces are removed in other equipment such as a steam jacketted pans or other vessels.
Said condense in the module comprises an overhead tubular condenser provided with cooling water circulation. The condenser is located directly above the vessel to ensure the shortest path for said freshly condensed solvent to the extraction vessel. Distributor means are provided, if required, to ensure proper and uniform distribution of the condensed solvent over the whole vessel cross-section. In the preferred embodiment the condenser body is of carbon steel and the tube bundle of stainless steel
Interconnected piping is provided for the solvent cycle, that is, vapourisation from reboiler, flow to said comdenser and condensation therein, entry into said vessel and draining firom said vessel to said reboiler. The drain line is provided with a sampling outlet wherefrom samples of said extract(s) are withdrawn periodically for indication of the solute content, that is, of the progress of the extraction.
The heat input to the reboiler, determines the rate of evaporation of the solvent and therefore, the rate of charging of said freshly condensed solvent to the extraction bed. As mentioned hereinbefore, said freshly condensed solvent collects in the seed bed and when the level thereof reaches the pre-determined level the collected solvent is drained into the reboiler. The time from one said draining to the next is referred to the cycle time. A low cycle time implies a high throughput of the solvent, that is, a high rate of heat input whereas a high cycle time means that the solvent remains in contact

in the bed somewhat longer during which said driving force tends to drop. Considering these factors, this invention provides that preferably said cycle times are from 15 minutes to 35 minutes. More preferably, the cycle times are bom 20 minutes to 30 minutes as in the preferred embodiment described further hereinbelow. Approximately, five minutes of each cycle tim represents the draining time and the rest the time during which the solvent collects in the bed.
Any method of conveying said seed material from and to said modules is within the scope of the invention. Preferably, however, (pneumatic means are employed as in the embodiments described Thus, in the preferred embodiment handling of the solid matter is entirely by pneumatic means which helps in preventing ingress of impurities in the food grade products of the process.
Said product mixture after the treatment with 98% ethanol is transferred to another agitated vessel
where chilled brine is circulated in the jacket thereof to reduce the temperature down to -10 C to -15
C.
At this point, said prooduct mixture separates out into:
i. a heavy phase comprising substantially pure oleoresin;
ii, a light phase comprising substantially pure fixed oils along with the 98% ethanol; and
iii. a small quantity of precipitated solid fat and wax matter.
Separation of said heavy phase bom the remainder is carried out by any known means such as decanting, filtration or others. The separated heavy phase is substantially pure oleoresin product.
The hot phase is also sutgected to separation by any one of known means to remove said fat and wax matter if any, lexnaining. The 98% ethanol used for treating said product mixture and remaining in said light base is evaporated off to give the product, namely, substantially {Hire fixed oils.

In order to provide a clearer understanding of the invention and without limitation to the scope of the
invention two embodiments of the process of the invention will now be described in detail by way of
example and further an embodiment of the extraction module apparatus of the invention will be described
with reference to the accompanying drawing wherein Fig. 1 shows the Extraction Module Apparatus for
carrying out the process of the invention.
Example I:
About 2 kgs. of healthy Fenugreek seeds were taken and cleaned to remove all extraneous matter such as
dirt, waste etc.
The seeds were then ground to -60 to + 90 B.S.S. The ground seeds were charged to the extractor of the
first stage, that is, in said stainless steel wire mesh basket of the first extraction vessel.
Petroleum Ether (40-60) was loaded into the reboiler. The vapour line from the reboiler has suitable
regulating means to direct the solvent vapour either to the extractor or to outside such as to condensation
and storage. The valves were adjusted to feed the vapour to the condenser from where the condensed
vapour flowed into the seed bed. The solvent began to collect in the bed. A cycle time of about 25 minutes
was used of which about 20 minutes was the time during which said solvent collected in the bed and
reached said pre-determined level which was fixed a few centimetres above the top of said bed. The
draining time was about five minutes. Six said cycles of extraction were carried out so that the total time of
the extraction was about 1.5 hours. The extraction was carried at a temperature of 50 C to 55 C.
The contact ratio over the whole extraction phase was about 1:2.5 to 1:3.5 (kg/litre). The seed material
from the seed bed of the first stage was removed and dried to remove to residual solvent and then charged
to second stage extraction module. The solvent was evaporated from the first extract and about 0.13 kg. of
said substantially pure fixed oil product was obtained.
About I kg. of the dried seed material obtained after first stage extraction was loaded into the second stage extraction module wherein the solvent was 95% ethanol. The same cycle time of 25 minutes was used and seven cycles were carried out the said overall extraction time being about three hours and the extraction carried out at a temperature of 78 C to 82 C. The contact ratio was about 1:2.5 to 1:3.5 weight/volume(kg71itre)

Said substantially pure dietary fibre obtained irom the second stage was dried in a small drier to remove the solvent traces and to bring down the moisture content to about 5%. The analysis of the dietary fibre obtained was:
Moisture 4.35% w/w
Protein 43.06% w/w
Fat Fibrous material 52.5% w/w The product obtained was of a very high purity and met all the requirements of a food grade product and more. In particular, attention is drawn to the extremely low fat content thereof. Solvent from said second extract was evaporated off in the second stage reboiler to yield said product mixture consisting of:
i. substantially all of the oleoresin in the seeds;
ii. substantially all of the fixed oils remaining in the seeds after first stage extraction;
iii. fat and waxy impurities if any, and iv. residual solvent and moisture.
Said product mixture was treated in a jacketted agitated vessel to about 111°C to evaporate the residual solvent and moisture and thereafter was cooled to about 40 °C. About 175 ml. Of 95%
ethanol was added and the mixture stirred for about one hour during which the temperature was
maintained at about 50° C.
Said treated mixture was cooled to about -10 C to -15 C by keeping it in an ice-salt bath. The treated
mixture separated into a light phase and a heavy phase.
The heavy phase was decanted and comprised the oleoresin fraction, that is, substantially pure oleoresin.

In a second embodiment, about 2 kgs. Fenugreek seeds after grinding to the size mentioned hereinabove were extracted in said first stage with n-hexane solvent. The contact ratio was about 1:3 w/v and the extraction was carried out at from 66 C to 71 C. The cycle time was about 25 minutes and the extraction was done for about 2.5 hours.
After the extraction the seed material was dried to remove solvent and then charged to second stage extraction. Solvent was separated from the first extract by simple distillation and 0.003 kg. of fixed oil
product was obtained, An apparatus to extract Dietary Fibre, fixed oils and Oleoresin from Fenugreek seeds is explained in the accompanying
drawings.
The rest of the extraction procedure was carried out as in the first embodiment.
The extraction module apparatus shown in Fig. 1 comprises a vessel 1 of stainless steel of circular cross
section. Said holding means for holding the solids to be extracted comprises a wire mesh basket 2 made of
stainless steel. Said basket 2 sits on the bottom plate 3 that fonns the bottom of the extraction compartment
wherein said freshly condensed solvent collects till it is drained into the reboiler. 4. Reboiler 4 comprises
steam coils (5) heating the extract contained therein so as to evaporate the solvent therefrom.
Drain line 6 allows periodical draining of the extract into reboiler 4. Solvent vapour flows through vapour line 7 into the vapour space above the wire basket 2. The solvent vapours rise into the condenser 8 and get cooled and condensed. Condenser 8 is of tubular type comprising tube bundle 9 of stainless steel. A vent 10 allows solvent vapours and other gases if any, to be vented to atmosphere when required. During operation the extract gets concentrated in reboiler 4 and when all the solvent is evaporated off the product remains. Said product is substantially pure fixed oils in case of stage 1 and a mixture of oleoresin and fixed oils in the case of stage 2 extraction. Said product can be removed through outlet 11.
A door 12 is provided on one side of said vessel 1 for introduction of the seed material required to undergo extraction and for withdrawing extracted(treated) solid material such as the wet dietary fibre and said partly treated seeds. Said charging and withdrawal of material is done by means of a portable pneumatic conveying unit having hoses for the suction and discharge of the solid material. Said hoses may be

introduced into the solids bed through said door 12. Provision is made in the interconnecting piping to move the solvent vapours to an outside condenser for condensation and storage of solvent when not required for the extraction process.
Two such extraction module apparatus are used in the process one for the first stage extraction and the other for the second.
Water is circulated in the condenser tubes to cool and condense the solvent vapours. In the drain line 6 an outlet is provided for periodical drawing of extract samples to measure the solute content.
Embodiments and variations other than described are feasible by persons skilled in the art and are within the scope and spirit of the invention.

We claim:
1. A process for the extraction of Dietary Fibre, Oleoresin and Fixed Oils from the seeds of
Fenugreek(Trigonella Foenum Graecum) comprising: i. optionally cleaning of said fenugreek seeds, and sorting, crushing, grinding and/or milling thereof;
ii. treating the said seeds with a substantially freshly condensed first solvent such as herein described in a first stage of extraction to yield a first extract and partly treated seeds; said first extract containing at least 75% of the fixed oils originally contained in said seeds together with the said solvent;
iii. further treating of the said partly treated seeds with a substantially freshly condensed second solvent such as herein described in a second stage of extraction to yield a second extract and said substantially pure wet dietary fibre, said second extract containing said oleoresin said substantially the whole of the remainder of said fixed oils contained in said partly treated seeds and said second solvent;
iv. drying of said substantially pure dietary fibre by heating upto temperatures
between 80-100 °C;
V. heating said first extract to temperatures below the boiling point of the said
first solvent so as to evaporate said first solvent therein to isolate said substantially pure fixed oils such as herein described;
vi. heating said second extract to temperatures below the boiling point of the said
second solvent to evaporate said second solvent therein to isolate a product mixture containing said oleoresin and substantially the whole of the remainder of said fixed oils contained in said partly treated seeds;
vii. treating said product mixture obtained in step (vi) with ethanol for a period of
time and at a temperature as herein described;
viii. cooling said treated product mixture to a temperature ranging from -10 °C to -15°
C obtain a heavy phase and a light phase;
ix. separating said heavy and light phases, preferably by decanting, said separated

heavy phase comprising said substantially pure oleoresin;
separating the crystallised impurities if any, such as fats and waxes from said light
phase preferably by filtering; and
evaporating ethanol from said light phase preferably by heating, to yield said
substantially pure fixed oils.
The process as claimed in preceding Claim 1 wherein said first solvent is selected from Petroleum Ether, Hexane, n-propanol and iso-propanol and said second solvent is selected from Ethanol, iso-propanol and aqueous ethanol.
The process as claimed in the preceding Claim 2 wherein said first solvent is
Petroleum Ether(40-60) and said second solvent is 90-95% ethanol.
The process as claimed in the preceding claims wherein said first extraction is
carried out at a temperature of 50 °C to 60 °C and said second at a temperature of 78 °C to
82° C.
The process as claimed in the preceding claims wherein said seed material is of size -60 to +90 B.S.S.
The process as claimed in the preceding claims wherein the ratio of the amount of said seed material to the amount of said solvent contacted in said first stage is 1:1 to 1:5 weight/volume(kg./litre) and in said second stage is 1:1 to

1:7 weight/volume(kg/litre).
The process as claimed in the preceding claims wherein said overall contact time in said first extraction stage is about 1 to 2.5 hours and in said second extraction stage is about 2 to 4 hours.
The process as claimed in the preceding claims wherein said frequency(number of times) of said drainings of said first and second extracts during extraction is 5 to 8 and 8 to 14 respectively.
The process as claimed in any of the preceding claims wherein said product mixture is treated with 98% ethanol for a period of time of from 45 minutes to 90 minutes, said temperature ranging from 45 C to 55 C.
The process as claimed in the preceding Claim 9 wherein the ratio of the amount of said product mixture to that of the amount of said 98% ethanol used for the treatment thereof is from 1:1 to 1:3.
An extraction module apparatus for carrying out said process as claimed in Claim 1 comprising:
i. an extractor vessel having means for holding said bed of solid materials to be
extracted;
ii. a reboiler; and
iii. a condenser;
interconnected such as to provide evaporation of said solvent in said reboiler, condensation of the vapours thereof in said condenser, contacting of said substantially freshly condensed solvent with said bed at upto substantially the condensing temperature thereof, and further comprising the necessary means for periodically draining said first and second extracts and for controlling heat input to said reboiler and other control means necessary.

extraction module apparatus as claimed in the preceding Claim wherein said holding means comprise a wire mesh basket made of stainless steel

The extraction module apparatus as claimed in any of the preceding Claims 11 and 12 wherein pneumatic conveying means are provided for charging material to, and discharging material from said vessel. A process for the extraction of Dietary Fibre, Oleoresin and Fixed Oils from the seeds of Fenugreek(Trigonella Foenum Graecum,) substantially as herein described. 15 An extraction module apparatus for carrying out said process as claimed in Claim 1, substantially as herein described and illustrated with reference to the accompanying drawing.

Documents:

112-mas-2000-abstract.pdf

112-mas-2000-claims.pdf

112-mas-2000-correspondence others.pdf

112-mas-2000-correspondence po.pdf

112-mas-2000-description complete.pdf

112-mas-2000-drawings.pdf

112-mas-2000-form 1.pdf

112-mas-2000-form 26.pdf

112-mas-2000-form 4.pdf

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Patent Number

192689

Indian Patent Application Number

112/MAS/2000

PG Journal Number

35/2005

Publication Date

16-Sep-2005

Grant Date

10-May-2005

Date of Filing

14-Feb-2000

Name of Patentee

RAO GARRIMELLA BHASKAR

Applicant Address

43/52, DR. JAGANNATHA NAGAR, AERODROME POST, COIMBATORE-641 014Q

Inventors:

#	Inventor's Name	Inventor's Address
1	RAO GARRIMELLA BHASKAR	43/52, DR. JAGANNATHA NAGAR, AERODROME POST, COIMBATORE-641 014
2	MR. PONRAJ, ANGAPPA MUDALIAR	KALYANI CHEMICAL CAMPUS, METTUR MAIN ROAD, NEAR BUS STAND, BHAVANI-638 102
3	MR. RAJENDRAN, THAVITTURPALAYAM KRISHNAN	636, NETAJI ROAD, SRI KRISHNA BIULDING, ERODE-638 001
4	MRS. PARVATHI, PONRAJ	KALYANI CHEMICAL CAMPUS, METTUR MAIN ROAD, NEAR BUS STAND, BHAVANI-638 102
5	MRS. SUJATHA, KRISHNAMMAL	4-1-32C, OPPOSITE R.C.PLANT, NEW COLONY, METTUR DAM, 636 403

PCT International Classification Number

D01B1/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA