Title of Invention

"A PROCESS FOR REDUCING HYGROSCOPICITY OF THE FREEZE DRIED FRUIT JUICE POWDERS"

Abstract The invention relates to a process to reduce the hygroscopicity of freeze-dried juice powders. The method consist of conversion of meta stable amorphous sugars to stable crystalline sugars, which are known.to be less hygroscopic. The juice/powder is exposed to a critical relative humidity for a period so as to convert amorphous liquid bridges between the crystallized sugars are removed by further drying in a freeze-drier for 2 to 3 hours. To prevent flavour loss during the crystalliztion process 0.5% of betacyclodextrin is incorporated into the liquid juice before pasteurization. Flavour loss is prevented to the extent of 80-90%. This process of controlled crystalliztion is of considerable help in preserving highly hygroscopic juice powder under uncertain/ humid environment weather conditions without affecting colour, flavour, appearance and acceptability for 10 to 12 months. The juice powder can be easily handled without stickiness and caking: and can be stored in pet/glass bottles.
Full Text FIELD OF INVENTION
This invention relates to a process for the preparation of free flowing, less hygroscopic freeze-dried fruit juice/pulp powders to improve handling properties and shelf stability.
PRIOR ART
Freeze dried fruit juice powders are considered to be the best next )nly to fresh products with respect to colour, flavour, texture and acceptability. The first and foremost problem in these products is their extreme hygroscopicity which affects not only the handling properties but also stability during humid weather conditions. The main reason for their extreme hygroscopicity, is the formation of meta stable amorphous sugars, during rapid removal of water content, under high vacuum and low temperature conditions, through sublimation. The amorphous sugars mainly glucose, fructose and sucrose try to regain their native crystalline state by absorbing moisture during handling and storage. This phenomenon results in formation of highly concentrated liquid bridges between the contact point of the particles, which in turn affect the flow property of the powder, and further absorption of water causes semi-solid and liquefaction stages.
Most of the research with respect to this problem has been concentrated on the incorporation of anticaking agents and other bulking agents, which help marginally and affect organoleptic properties of the reconstituted juice. However no satisfactory process has been reported so far regarding the improvement of hygroscopicity related problems in freeze-dried juice powders without affecting the flavour, colour and taste. One of the known process as described in US patent Nos -3953615, 400135 and 4537637 describes the use of dextrose/maltose for the hydration drying process of coffee, tea and juice concentrates.
The main limitation of above known process is that addition of dextrose/maltose affects of the taste of the powder.
Agglomeration technique known in the art is also followed to improve the handling properties of health drinks like boost, maltova, horlicks etc.

The limitation of the above known technique is that it does not help to prevent the up take of water at ambient conditions.
OBJECTS OF INVENTION
The main object of the present invention is to provide a process for reducing hygroscopicity of freeze-dried juice powder.
Another object of the present invention is to provide a process for reducing hygroscopicity of freeze-dried juice powder wherein the organoleptic attributes of the reconstituted juice are not affected.
Yet another object of the present invention is to provide a process for reducing hygroscopicity of freeze-dried juice powder wherein the flavour loss during crystallization of juice powder is prevented.
Still another object of the present invention is to provide a process for reducing hygroscopicity of freeze-dried juice powder wherein the rehydration properties are stable upto 12 months.
Further object of the present invention is to provide a process for reducing hygroscopicity of freeze-dried juice powder wherein the handling of the product is easy without stickiness and caking.
Yet further object of the present invention is to provide a process for reducing hygroscopicity of freeze-dried juice powder which is cost effective.
Still further object of the present invention is to provide a process for reducing hygroscopicity of freeze- dried juice powder which can even be stored in pet/ glass bottles.
DESCRIPTION OF FIGURES
Figure 1- Shows the effect of controlled crystalliztion and anticaking agents on hygroscopicity of freeze dried mango juice powder exposed at 63.3% Relative humidity for 24 hours.
Figure 2(a)- Shows the X-ray diffraction pattern of the ordinary- freeze dried mango juice powder.
Figure 2(b)- Shows the X-ray diffraction pattern of the freeze-dried mango juice powder of the present invention.
DETAILED DESCRIPTION OF PROCESS
According to this invention there is provided a process for reducing hygroscopicity of the freeze- dried fruit juice powders comprising of the steps of:
a) preparing pulp/ juice of fresh washed fruits and removing the fibrous material by filtering, adding 0.15- 0.6 w/w % preferably 0.3 - 0.5 w/w % B cyclodextrin to the said filtered pulp/juice and then pasteurising it, cooling the pasteurised pulp/ juice to a temperature of 25 - 30° C by circulating cold water and then
adjusting acidity and brix of the said pasteurised pulp/juice to 1.5% and 20 respectively;
b) freezing the juice/pulp from step a) at - 40°C + 2°C for 4 -5
hours in a blast freezer and than dehydrating the said frozen
juice/pulp mass in a freeze-drier under a chamber pressure of
100 to 150 u at a variable platen temperature not above 50°C, transferring the said frozen and dried pulp/juice to a room having 20 + 2°C humidity and 25+2°C temperature, pulverizing the said pulp/juice to and then spreading it to a uniform thickness;
c) rehumidification of the said pulp/juice powder from step b) in a
chamber maintained at 33 - 43% RH for 18-24 hours followed
by controlled crystallization of the said pulp/juice powder under
vacuum in a freeze dried for 6 to 8 hrs and pulverizing in a mill
to get a free flowing powder.
In accordance with the present invention the process for reducing hygroscopicity of the freeze died fruit juice/pulp powders from pineapple, mango and citrus fruits comprises of the step of :-
a) Preparation of pulp/juice
Good quality fruits are washed in running water containing 0.1% permanganate solution to remove surface contaminants. After peeling and trimming the fruits are subjected to juice extraction in a screw type juice extractor/ pulper. Extracted juice/pulp is filtered through 60mesh sieve to remove fibrous materials in case of pineapple and
citrus fruits. B cyclodextrin at a level of 0.15 - 0.6 w/w % preferably 0.3 - 0.5 w/w % is incorporated into the filtered juice/pulp. Juices are pasteurised at about 80°C for about 5 min in an electrically headed pasteuriser and cooled to room temperature of 25 - 30°C by circulating cold water. Acidity and brix of the cooled pasteurised juice/pulp are adjusted to 1.5% and 20 respectively, using A.R Grade citric acid ( assay 99%) and previously dried and cooled crystalline cane sugar.
b) Freezing and dehydration
The juice/pulp from step a) is frozen to - 40°C ± 2°C for 4 -5 hours in a blast freezer. Frozen juice/pulp mass is transferred to a freeze -drier and dehydration is carried out under a chamber pressure of 100 to 150 u and at a variable platen temperature so that the product temperature does not rise above 50°C. After the product is dried to The juice powder is then pulverized in a pulverizer fitted with 8 mesh sieve to get a uniform particle size of 2057u and is then spread on stainless steel trays to a uniform thickness of 5 mm.
c) Rehumidification/controlled crystallization
The juice powder from step b) is subjected to rehumidification in a chamber maintained at 33 - 43% RH for 18 - 24 hours. After rehumidification, the juice powder is transferred to the freeze drier for drying under vacuum and refrigeration for 6 to 8 hrs to remove the water from highly concentrated liquid bridges between the particles. After dehydration the product is pulverized in a Raymond mill fitted with 8 mesh sieve to get a free flowing powder.
This invention will now be illustrated with a working example, which is intended to be a typical example to explain the technique of the present invention and is not intended to be taken restrictively to imply any limitation to the scope of the present invention.
Working example
50 kg of ripe, Alphonso variety mangoes were washed in water containing 0.1% permanganate solution to remove surface contaminants. Washed fruits were subjected to de-skinning. De-skinned fruits were cut in to 2 to 3 parts and fed in to a pulper for pulp extraction (20kg). 0.25% BCD was incorporated in the pulp and it was pasteurised in an electrical pasteuriser at 80°C for 5 minutes. Pasteurised pulp acidity and brix was adjusted to 1.5% and 20 by adding AR grade citric acid (assay 99%) and previously dried crystalline sugar. Then the pulp was frozen to 40°C for 4 hrs in blast freezer and transferred to dried for drying at 100 to 150
microns pressure under refrigeration. The dried pulp was unloaded by breaking the vacuum using commercial nitrogen gas and quickly transferred to dehumidified room where relative humidity was maintained below 23%. Dried pulp was pulverized in a Raymond mill fitted with 8 mesh sieve.
The powdered pulp was spread on stainless steel trays and the thickness was maintained through out for 5 mm and exposed to 43% relative humidity for 24 hours. After rehumidification the product was further dried in freeze dried under vacuum and refrigeration for 6 hrs to remove water content between the particles. Dried pulp powder was further subjected to pulverization and packed in paper Foil Polythene (PFP) pouches.
Evaluation of the freeze-dried juice powders
The process for the preparation of freeze dried fruit juice/pulp powder of the present invention showed no flavour loss during pasteurisation as well as crystallisation, it does not require packaging films with nil barrier properties and can be easily be stored in pet/glass bottles. It also showed god free flowing properties up to 60% relative humidity and could be handled easily without stickiness and caking (Fig-1) The X-ray diffraction pattern of the ordinary freeze dried mango juice and freeze dried powder of the present invention also shows this clearly (Figures- 2(a) and 2(b)).

It is to be understood that the present invention is susceptible to modifications, changes and adaptations by those skilled in the art. Such modifications, changes, adaptation are intended to be within the scope of the present invention which is- further set forth under the following claims:-






We claim:
1. A process for reducing hygroscopicity of the freeze- dried fruit juice powders comprising of the steps of:
a) preparing pulp/ juice of fresh washed fruits and removing the fibrous material by filtering, adding 0.15 - 0.6 w/w % preferably 0.3 - 0.5 w/w % B cyclodextrin to the said filtered pulp/juice and then pasteurising it, cooling the pasteurised pulp/ juice to a temperature of 25 - 30° C by circulating cold water and then adjusting acidity and brix of the said pasteurised pulp/juice to 1.5% and 20 respectively;
b) freezing the juice/pulp from step a) at - 40°C + 2°C for 4 -5 hours in a blast freezer and than dehydrating the said frozen juice/pulp mass in a freeze-drier under a chamber pressure of
100 to 150 u at a variable platen temperature not above 50°C, transferring the said frozen and dried pulp/juice to a room having 20+2°C humidity and 25 + 2°C temperature, pulverizing ( the said pulp/juice to and then spreading it to a uniform d thickness;
c) rehumidification of the said pulp/juice powder from step b) in a
chamber maintained at 33 - 43% RH for 18 - 24 hours followed
by controlled crystallization of the said pulp/juice powder under
vacuum in a freeze dried for 6 to 8 hrs and pulverizing in a mill
to get a free flowing powder.

2. A process for reducing hygroscopicity of the freeze- dried fruit juice powders as claimed in claim 1 wherein the said acidity and brix is adjusted by A.R. Grade citric acid (assay 99%) and previously dried and cooled crystalline cane sugar.
3. A process for reducing hygroscopicity of the freeze- dried fruit juice powders as claimed in claim 1 wherein the said dehydration of the frozen fruit juice/pulp under pressure is carried upto a moisture level of 4. A process for reducing hygroscopicity of the freeze- dried fruit
juice powders as substantially described and exemplified herein.

Documents:

2604-DEL-2004-Abstract (20-11-2007).pdf

2604-del-2004-abstract.pdf

2604-del-2004-claims.pdf

2604-DEL-2004-Correspondence-Others (20-11-2007).pdf

2604-del-2004-correspondence-others.pdf

2604-del-2004-correspondence-po.pdf

2604-del-2004-desctiption (complete).pdf

2604-del-2004-drawings.pdf

2604-del-2004-form-1.pdf

2604-del-2004-form-2.pdf

2604-DEL-2004-Form-3 (20-11-2007).pdf

2604-del-2004-form-3.pdf

abstract.jpg


Patent Number 248277
Indian Patent Application Number 2604/DEL/2004
PG Journal Number 27/2011
Publication Date 08-Jul-2011
Grant Date 01-Jul-2011
Date of Filing 31-Dec-2004
Name of Patentee THE DIRECTOR GENERAL,DEFENCE RESEARCH & DEVELOPMENT ORGANISATION, MINISTRY OF DEFENCE (GOVT. OF INDIA)
Applicant Address DEFENCE RESEARCH & DEVELOPMENT ORGANISATION MINISTRY OF DEFENCE, GOVT. OF INDIA, WEST BLOCK-VIII, WING-1, SECTOR-1, R.K.PURAM, NEW DELHI-110 066
Inventors:
# Inventor's Name Inventor's Address
1 HANUMANAHALLY SHANKARIAH PHANINDRAKUMAR DEFENCE FOOD RESEARCH LABORATORY SIDDARTHNAGAR POST OFFICE MYSORE-570011
2 PALAYAMKOTA KARIAPPA NAGARAJU DEFENCE FOOD RESEARCH LABORATORY SIDDARTHNAGAR POST OFFICE MYSORE-570011
3 KOLPE RADHAKRISHNA DEFENCE FOOD RESEARCH LABORATORY SIDDARTHNAGAR POST OFFICE MYSORE-570011
4 AMARINDER SINGH BAWA DEFENCE FOOD RESEARCH LABORATORY SIDDARTHNAGAR POST OFFICE MYSORE-570011
PCT International Classification Number A23L2/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA