Description
The maize protein (Zein) and protein from jowar have been extracted by wet milling which is an expensive process to separate various fractions like starch, oil and gluten (maize protein). To avoid the complicity of the process by doing it by conventional isolation which involves technical problems due to tendency of well knit protein with starch making a matrix, fibre and germ strictly adhered in gran specially in corn. The process needs huge quantity of water and production of high BOD corn steep liquop which is not eco-friendly.
By the present invention, we have overcome the above problem encountered with maize grain and utilize the broken rice grains which do not get much entry into human food like the whole grain. The broken rice has been found to contain highest polysaccharide as starch along with edible protein in contrary to maize which has 'Zein', ' protein which is not digested by humans. The highest starch content makes the grain viable for producing hydrolysates out of it along with protein (rice gluten) which finds its application in supplementation of human food and poultry feed/animal feed. The starch hydrolysates can be produced of various dextrose equivalent and dry solids which finds its application in dairy, confectionery, bakery, caramel industry.
The rice gluten has 15 to 45 per cent of water soluble carbohydrates against 26 to 28 per cent water insoluble carbohydrates in maize gluten. The water soluble simpler saccharides are quick source of energy.
A preferred embodiment of the invention is the removal of husk in dry form before the grain takes part in reaction.
Another embodiment of the process is dry grinding whereas in case of corn it is very lengthy wet process.
A further preferred embodiment of the process is it of being ecofriendly whereas in case of wet corn milling high BOD containing liquid is an environmental problem.
A preferred embodiment of the invention is characterised by rice gluten having soluble saccharides alongwith its protein whereas com gluten has water insoluble carbohydrates with its protein which is Zein.
Another embodiment of the invention is separation of protein fraction by liquification of starch content by a -amylase alone and in combination with fungal amylase or P-amylase.
The further object of invention is an economically available raw material and economical process. The invention, therefore, concerns in a preferred embodiment the use of broken rice and enzymatic route.
A process for preparing gluten (protein) from rice wherein the said rice is ground, pulverized to 30-120 mesh size; said rice powder is mixed with water to form a slurry of 5 to 40% solids using an agitator with variable speed to give 20 - 80 rpm; alpha amylase is added at the rate of 400 to 800 ml per MT of available dry starch adjusting the pH in the range of pH 5.2 - 6.0 in said rice powder followed by heat treatment at 95°C for I¼¸ to 4 hrs where said starch fraction gets solubilised and insoluble fraction is separated by filtration; and gluten is obtained.
This invention is not restricted to broken rice but is equally applicable for whole rice.
Following are the details of processes adopted for various fractions and products:
The poultry business is always in demand of protein and energy source. Rice protein has given a new opening to its application because of it having additional source as soluble saccharides which is contrary to maize gluten which has insoluble polysaccharide. Rice gluten (protein) is edible and can form a part of human diet whereas maize protein is a Zein not or very less digested by humans.
The polysaccharide hydrolysates produced during the process can be tailor-made for making a part of dairy/coffee whitener, confectionery, bakery, caramel etc.
Cleaned broken ground rice 30 to 120 mesh was suspended in water to make a slurry of 5 to 40 per cent solids using agitator with variable speed to give 20 to 80 rpm. The slurry was maintained at temperature of 22 to 30° C. The agitation was continued for 10 to 20 minutes. Termamyl LC, an alpha-amylase was added at the rate of 400 to 800 ml per MT of dry starch. The pH of the solution was maintained at 5.2 to 6.0, the level of calcium was maintained between 30 to 80 ppm. The solution passed through jet cooker of 80 LPM alongwith steam to pass through and give 105 to 110° temperature. Extra steam allowed to escape and the resultant solution subjected to thorough mixing and reaction allowed to continue at 95° C for 154 to 4 hours. The solution cooled to 55° C to 60° C which contains suspended protein in liquid phase. The mixture is passed through RVF or filter press. The filtrate collected for further treatment and cake washed with water. The washed cake crushed to make wet powder which was dried by steam through ring drier and flash drier to get powder of maximum 10 per cent moisture, 47 per cent protein, 34 per cent carbohydrate, 7 per cent fat and 2 per cent fibre.
Filtrate from No. 1 used for following:
Filtrate of No. 1 having dextrose equivalent of 18 to 20 was treated with activated carbon at 70 to 75°C for 30 minutes. Filtered and material passed through deashing unit comprising of cation and anions units. The deashed material subjected again to activated carbon of 180 MB value at 70 to 75°C for 30 minutes and again filtered. Material evaporated to 45 per cent solids and spray dried to give a powder of moisture 4 per cent, dextrose equivalent 19.2, pH 6.1 and BD of 0.62 g/ml.
Filtrate of No. 1, having dextrose equivalent of 15 to 16, treated with fungamyl 100 ml/MT of available starch solids at 55° C and pH of 5 to 5.6 for 4 to 6 hours to attain dextrose equivalent of 28 to 30. The solution given the same treatment as in No. 2. The powder obtained was of 4 per cent moisture, dextrose equivalent 28, pH 6.0 and BD of 0.57 g/ml.
Filtrate from No. 1 treated with 20 to 50 ml of B-amylase at 4.2 to 4.4 pH per MT of starch for 8 hours at 55 to 60° to attain a dextrose equivalent of 28 to 42. The reaction terminated by raising the pH to 5.0 and followed the steps as in No. 2 up to evaporation under vacuum to attain dry solids of 86 per cent, dextrose equivalent 40, pH 5.0. Low dextrose equivalent glucose liquid can be made for low dextrose equivalent liquid glucose of 28 to 30 dextrose equivalent. The reaction time reduced to 4 hours to give a product of dextrose equivalent 28, dry solids 80 per cent and pH 5.2.

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We claim:
1. A process for preparing gluten (protein) from rice wherein the said rice is ground, pulverized to 30-120 mesh size; said rice powder is mixed with water to form a slurry of 5 to 40% solids using an agitator with variable speed to give 20 - 80 rpm; alpha amylase is added at the rate of 400 to 800 ml perMT of available dry starch adjusting the pH in the range of pH 5.2 - 6.0 in said rice powder followed by heat treatment at 95°C for 1½ to 4 hrs where said starch fraction gets solubilised and insoluble fraction is separated by filtration; and gluten is obtained.
2. A process as claimed in claim 1 wherein the insoluble gluten fraction is separated by subjecting to Rotary Vaccume Filter (RVF) press & basket centrifuge to separate the insoluble protein in wet form, the said wet gluten is subjected to grinding in Ribbon Blender, rotary drier / flash drier & ring drier so that powdered product having maximum of 47% protein, 34% soluble carbohydrates, 7% fet, 10% moisture & 2% fibre.
3. A process as claimed in claim 1 the clear filterate which is primarily polysaccharide hydrolysates is purified by activated carbon & ion exchange treatment & other refining treatments.
4. A process as claimed in claim 3 wherein the clear transparent liquid is concentrated by multiple effect or batch evaporator or dried with spray drier.
5. A process for preparing gluten (protein) from rice substantially as herein described.