Title of Invention

A PROCESS FOR THE PREPARATION OF GREEN COFFEE CONSERVE HAVING RADICAL SCAVENGING PROPERTY

Abstract

The invention relates to a process for the preparation of coffee conserve from low grade green coffee beans. This is the first report of a process for the isolation of radical scavenging conserves from the low grade green coffee beans. The extract of coffee beans can be used to scavenge the radicals in food systems. A simple extraction technique is used to prepare a radical scavenging conserve from low grade green coffee beans with/without heat treatment which can be used as a natural radical scavenger in food applications.

Full Text

This invention relates to the process for the preparation of green coffee conserve from coffee beans, in particular low-grade coffee beans. Coffee is one of the international products which belongs to Rubiaceae family with more than 70 species but two of them are of significant economic importance namely, arabica (Coffea arabica) and robusta (Coffea canephora). According to the latest estimate of the International Coffee Organization (ICO), total coffee production is 72 Lakh tonnes with India's contribution is 4.1%. The low-grade coffee representing about 15-20% of coffee production on weight basis is a problem for disposal in the world market. The ungraded and ungarbled coffee after grading according to the size and color is termed as 'low grade' or 'bulk' which contain blacks and dark brown beans and shall include damaged beans such as bleached beans (spongy), spotted beans (more than a quarter of a bean surface), insect damaged beans, sours, bits and greens (immature beans). Low-grade coffees are obtained as a result of either improper formation within the fruit or by faulty processing. For commercial purposes these are considered as defects, a term used to describe the quality factor of the amounts of defective beans or extraneous matter in a coffee sample. Nearly 12-15 lakh tonnes is generated in the coffee industry every year and low grade coffees are rejected in the international market due to the undesirable taste produced in the beverage. The ICO believes consumers will turn to alternative uses if manufacturers continue to substitute low-grade beans. It is worthwhile to find ways and means of its utilization. Antioxidants play a crucial role in preventing or delaying autoxidation and have attracted a lot of attention as food additives. Both synthetic and natural antioxidants are widely used in many food products. The subject of natural antioxidants has been developing since past decade, mainly because of the increasing limitations on the use of synthetic antioxidants and enhanced public awareness of health issues. In general, consumers prefer natural antioxidants because these are considered safe and environmental friendly. There has been a growing interest in replacing them with natural ingredients due to possible toxicity of synthetic antioxidants. Further, the use of some common synthetic antioxidants such as butylated hydroxy anisole (BHA) and butylated hydroxy toluene (BHT) has become controversial issue because of adverse toxicological data and the use of BHT is already banned in India. Hence, evaluation of the antioxidative activity of naturally occurring substances has been of interest in recent years. Reference may be made to a United States patent No : 6,669,979 (2003) by Zhao et al wherein a process for increasing the levels of release poiyphenolic acids in coffee brew from roasted and ground coffee is disclosed. The present patent deals with the preparation of radical scavenging conserve from low grade green coffee beans. Reference may be made to a United States patent No : 5,714,094 (1998) by Bertholet et al wherein a process for the preparation of antioxidant conserve from coffee oil comprising lipids and carboxylic acids is explained. The present patent deals with the preparation of radical scavenging conserve from low-grade green coffee beans. Literature survey revealed the antioxidant activity of green coffee beans but there is no report for the isolation of coffee conserve from low-grade green coffee beans. The main object of the present invention is to provide a process for the preparation of coffee conserve from the low-grade green coffee beans. Accordingly the present invention provides a process for the preparation of green coffee conserve which comprises the following steps, i. grinding the low grade green coffee beans to a particle size ranging 400 - 900 microns, ii. de-fatting the powder with a non polar solvents such as linear or branched alkanes and /or their mixture, iii. extracting the powder with or without heat treatment using a polar solvent such as lower alcohols or ketones, iv. removal of solvent at lower temperatures (>40°C) to obtain coffee conserve, v. testing of radical scavenging activity using Diphenyl picryl hydrazyl radical method vi. estimating the components responsible for the radical scavenging activity especially total polyphenol and chlorogenic acid. In an embodiment of the present invention, the low-grade green coffee beans can be of any variety such as arabica and robusta processed by both dry and wet method and the mixture thereof. In another embodiment of the present invention, the mill used for powdering in step (i) may be multimill fitted with a sieve to obtain coarse powder of micron size 500-800. In yet another embodiment, the powder is defatted using a solvent in step (ii) which may be a linear or branched hydrocarbon, such as pentane, hexane, heptane and their mixtures etc., In yet another embodiment of the present invention, the solvents used in step (iii) may have an alcoholic functional group with an aliphatic chemical nature, such as methanol, ethanol, acetone, ethyl methyl ketone. In yet another embodiment of the present invention, the removal of solvent in step (iv) may be done in the range of 10-40°C. In still another embodiment of the present invention, the radical scavenging activity of the conserve is about 80-95% at 100 ppm concentration. In still another embodiment of the present invention, the conserve has the total polyphenol content of about 18-30% (gallic acid equivalents) and chlorogenic acid content of 20-40% The process for the preparation of conserves from the low-grade green coffee beans consists of the following steps. Green coffee beans were ground to particle size of 400-900 microns, and defatted with the non polar solvents such as petroleum ether, hexane etc. The defatted powder was extracted with the lower alcohols either in a soxhiet extractor or by column extraction. The extract was desolventized and analysed for evaluation of radical scavenging activity, for determination of total polyphenol content and chlorogenic acid content. Radical scavenging activity by DPPH model system The coffee extracts at different concentration (50 & 100 ppm) and BHA were taken in different test tubes. Sample solution (0.1ml) was taken and the volume adjusted to 1ml by adding methanol in a test tube. Methanolic solution of DPPH (4 ml of 0.1 mM) was added to these tubes and shaken vigorously. The tubes were allowed to stand at 27°C for 20 min. The control was prepared as above without any extract and methanol was used for the baseline correction. Optical density (OD) of the samples were measured at 517nm. Radical scavenging activity was expressed as the inhibition percentage and was calculated using the following formula, Radical scavenging activity, % = (Control OD - sample OD/Control OD) X100 Novelty of the process lies in preparing a radical scavenging conserve from low grade green coffee beans that can be used as a natural radical scavenger in food applications. Novel inventive step involves in the isolation of radical scavenging conserves using simple extraction technique with or without the heat treatment. The following examples are given by way of illustrations of the present invention and therefore should not be construed to limit the scope of the present invention. Example-1 Low-grade green coffee beans (arabica plantation), after grading according to the size and colour, were obtained from coffee curing works. The green coffee beans were ground to a particle size of 600 microns. The ground powder (100g) was loaded in a glass column (50 cm length with 1.5 cm diameter) fitted with a stopcock. The column was tapped gently to get a moderate packing. The powder was defatted with hexane (600 ml). The defatted coffee powder was loaded in the column and about 200 ml of methanol was added with stopcock open and the solvent was allowed to percolate for 8 hrs at room temperature. The extract was collected completely. The process of extraction was repeated two times with the addition of 200 ml each of methanol. The extracts were combined and desolventised in rotavapour at 40°C to get the extract of 8.3g. The extract had a radical scavenging activity of 88% compared to a synthetic antioxidant, BHA which showed 87% at 100 ppm concentration. The dried extract has total polyphenol (21.01%, gallic acid equivalents) and chlorogenic acids (21.72 %), which are responsible for radical scavenging activity. Example-2 The low-grade commercial green coffee (100g) was transferred to a soxhiet apparatus and defatted with hexane for 8 h. The defatted powder was extracted with methanol (600 ml) in a soxhiet apparatus. The ratio of powder to eluting solvent was 1:6. Solvent was removed from the eluate at 50°C. The yield of the conserve 2 was 16.0%. The extract exhibited radical scavenging activity of 90% by DPPH method at 100 ppm concentration. The dried extract had total polyphenol (21.84 %, gallic acid equivalents ) and chlorogenic acids ( 22.02 %) which are responsible for radical scavenging activity. Example - 3 The low-grade green coffee beans, dry processed robusta, were ground to a particle size of 600-700 microns. The ground powder (100g) was loaded in a glass column (50 cm length with 1.5 cm diameter) fitted with a stopcock. The column was tapped gently to get a moderate packing. The powder was defatted with hexane (600 ml). The defatted coffee powder was loaded in the column and about 200 ml each of methanol was added with stopcock open and the solvent was allowed to percolate for 8 h at room temperature. The extract was collected completely. The process of extraction was repeated two times with the addition of 200 ml of methanol. The extracts were combined and desolventised in rotavapour at 40°C to get the extract of 11.3g. The extract exhibited radical scavenging activity of 90% by DPPH method at 100 ppm concentration. The dried extract has total polyphenol (21.09 %, gallic acid equivalents) and chlorogenic acids (22.87 %), which are responsible for radical scavenging activity. The advantages of the process are: 1. This is the first report of a process for the isolation of radical scavenging conserves from the low grade green coffee beans 2. The extract of coffee beans can be used to scavenge the radicals in food systems 3. Low-grade coffee green beans are presently rejected in the international market; therefore radical scavenging conserve, a value added product, can be explored for export market as a natural antioxidant. We claim: 1. A process for the preparation of coffee conserve from low grade green coffee beans , comprising 18- 30% total polyphenols (gallic acid equivalents) and 20- 40% chlorogenic acid having radical scavenging property, which comprises the steps of: i) grinding the green coffee beans selected from a single variety or mixture of varieties thereof to obtain a powder form having particle size in the range of 400 - 900 microns; ii) de-fatting the powder by a known method using non-polar solvents selected from the group consisting of pentane, hexane, heptane and mixture thereof; iii) extracting the powder by a known method for a period in the range of 4-15 hours using polar solvent selected from the group consisting of methanol, ethanol, acetone, ethyl methyl ketone, optionally with heat treatment; iv) removing solvent at lower temperature in the range of 0-40 deg C in order to obtain the said coffee conserve; v) testing radical scavenging property of the coffee conserve obtained in step (iv) using Diphenyl picryl hydrazyl (DPPH) radical method; and, vi) estimating the components responsible for the radical scavenging property selected from total polyphenol and chlorogenic acid. 2. A process as claimed in claim 1, wherein the yield obtained in in step (iv) of claim 1 is in the range of 8 - 20%. 3. A process as claimed in claims 1-2, wherein the radical scavenging activity of the coffee conserve obtained in step (iv) of claim 1 is in the range of 80-95% at 100-ppm concentration. 4. A process as claimed in claims 1-3, wherein the said coffee conserve is used as an anti oxidant agent in food system in order to scavenge radicals therefrom. 5. A process for the preparation of coffee conserve from low grade green coffee beans, substantially as herein described and exemplified in the accompanying examples.

Documents:

729-DEL-2005-Abstract-(03-06-2011).pdf

729-del-2005-abstract.pdf

729-DEL-2005-Claims-(03-06-2011).pdf

729-del-2005-claims.pdf

729-DEL-2005-Correspondence Others-(03-06-2011).pdf

729-del-2005-correspondence-others.pdf

729-del-2005-description (complete).pdf

729-del-2005-description (provisional).pdf

729-DEL-2005-Form-1-(03-06-2011).pdf

729-del-2005-form-1.pdf

729-del-2005-form-18.pdf

729-del-2005-form-2.pdf

729-DEL-2005-Form-3-(03-06-2011).pdf

729-del-2005-form-3.pdf

729-del-2005-form-5.pdf