What is the comprehensive utilization of rice protein?

China as the world’s largest rice production country, in the rice plantation industry is booming at the same time, the deep processing and comprehensive utilization of rice for China’s agricultural economy provides a new growth point. Rice processing is often only the use of starch, broken rice, rice embryo, rice bran, rice husk and other processing by-products contain a large number of high-quality rice protein can not be effectively developed and utilized, resulting in a great waste of protein resources.
With the continuous progress of food science and technology, the high nutritional properties of rice protein, hypoallergenic gradually recognized by the people, the development of food or nutritional health products as a processing base material has become a major trend. This paper provides an overview of the comprehensive benefits of rice protein.
Domestic and foreign research on rice protein mainly includes food additives to improve the physical and chemical functions of food; as a natural thickener and foaming agent for toiletries; high-protein nutritional powders needed by special populations; biologically active peptides to meet specific functions; active ingredients to promote the health care of the organism; protein feed for livestock and poultry production; and environmentally friendly edible membranes, etc., which are closely related to the hydrolysis and modification of rice protein isolate (RPI). modification of rice protein isolate (RPI).
Food Additives
Food additives are a class of additives that can improve the quality, color, aroma and taste of food. The right molecular size and amino acid composition will give proteins certain physical and chemical properties, such as solubility, foaming and emulsification.
Rice protein is more easily soluble in water and concentrated at the gas-liquid interface under the hydrophobic, flexible, and disordered structure, showing foaming emulsification. Wu Yujing used rice dregs as raw material and obtained protein foaming powder with high protein content and good foaming performance through a series of processes, such as desugarization, neutral protease enzyme modification, decoloration and drying.
Anderson et al with protease treatment of rice isolate protein, so that 10% protein solution apparent viscosity decreased significantly, foaming capacity and foam stability greatly enhanced.
Improve the nature of rice protein in addition to enzymatic hydrolysis, the same can be used to chemical modification means, such as the addition of Na2SO3 or SDS can be lifted protein molecules aggregation state, showing colloidal properties.
After the above enzymatic hydrolysis or modification of rice protein in food production has a wide range of uses, such as in liquid or semi-solid food stabilization, thickening effect, in baked goods and confectionery foaming effect.
Protein Nutritional Supplement
With its hypoallergenic and highly nutritious properties, rice protein has become the plant protein of choice for supplementation of special populations. Rice protein formulated rice flour can target sensitive diarrhea in infants and young children; gluten-free rice protein is more suitable for people with wheat intolerance, allergy or celiac disease; rice protein concentrate can better supplement the body’s ability to maintain nitrogen balance when the intake of normal protein is reduced or when that digestive function is impaired; and it can assist in the treatment of digestive ulcers, trauma and so on.
Functional peptide development
Modern research shows that amino acid residues in small molecule peptides are easier to be digested and absorbed by the human body compared with free amino acids. The existence of amino acids in the form of small molecule peptides not only avoids transport competition, but also reduces the toxic side effects of high concentration of amino acids, peptide transport system is low energy consumption and not easily saturated, making the study of hydrolyzed protein products to obtain active peptides is welcomed by people.
Li Huoyun et al. used Alcalase alkaline protease enzyme to hydrolyze rice protein to obtain rice peptides capable of eliminating p-hydroxyl radicals, superoxide anion radicals and DPPH free radicals, which provides a guarantee for inhibiting and delaying the aging of the organism, and opens up the prospects for the application of anti-aging cosmetics.
The active peptide in rice isolate protein can affect the expression of cyp4a and cyp2c, thus improving the metabolism of arachidonic acid as an anti-hypertensive component. In addition , it was able to inhibit atherosclerosis in a hereditary high cholesterol mouse model and reduce the incidence.
The small molecule peptides of rice proteolytic digests are diverse and functional. Such as antibacterial active peptide, cholesterol-lowering active peptide, antihypertensive active peptide, anti-tumor active peptide, antioxidant active peptide and so on.
Protein feed
Rice protein powder, a by-product of amylose preparation in rice, is an excellent feed raw material with high protein content, fast energy conversion, high digestibility, good palatability, good disease resistance, low antigenicity and amino acid balance. Adding the concentrate of rice gluten in aquatic feed can not only improve the digestive performance of fish, but also control its excretion, thus keeping the water quality clarified and controlling water pollution.
Enzymatic digestion of rice protein can produce flavor peptides to replace monosodium glutamate (MSG), which can effectively mask the bitter taste, enhance the viscosity and improve the palatability of feeds, and can chelate trace elements and minerals, which can increase the feed intake of the animals and at the same time ensure the safety and harmlessness.
Liu Weidong et al. added 1.5%~2% of rice protein as chicken feed significantly increased the egg production rate, feed intake, total protein in blood and survival rate of chickens.
Edible film
Rice edible protein film made from rice milling industry by-products of broken rice, is a kind of green packaging film with good freshness, gas barrier, oil barrier, moisture resistance, promoting the development of edible packaging film materials, for renewable agriculture to open up a new way.
Wu Yinghua and other research on rice protein film molding conditions show that, at a constant temperature of 4O ℃, with a mass fraction of 80% ethanol dissolution of rice protein, can be formed on a smooth stainless steel plate with a certain strength of edible film, and the addition of oleic acid and glycerol can improve the transparency of the film and tensile strength. South Louisiana Research Center in the United States developed a tensile and water vapor resistant edible film, which is made of rice protein concentrate and pullulan polysaccharide conjugate, the edible film can be used as flavor substances, nutrient additives carrier or as a separation, protection and preservation of isolates.