Discover the benefits of rice protein – a high-quality, low-allergenic dietary solution for infants, fitness, and sustainable packaging. Explore now!

Development and Application of Rice Protein

Rice is one of the world’s essential cereal crops and a crucial source of protein for humans. As the country with the highest rice production globally, China relies on rice not only as a staple for southern residents but also as a vital ingredient in the food industry, used in products such as fillings, monosodium glutamate, glucose, brewing, and maltodextrin. Among these, rice protein (RP) refers to the collective term for proteins derived from rice and is generally found in rice processing by-products. It possesses a balanced amino acid composition, easy digestibility, and low allergenicity, making it a high-quality dietary protein. Compared to wheat and corn proteins, rice protein has lower allergenicity and better digestibility, making it widely recognized as a superior dietary protein with broad prospects in infant food and high-end food products.

Extraction and Application of Rice Protein

The primary purpose of extracting rice protein is to obtain high-purity rice protein. Currently, both domestic and international methods for extracting rice protein include alkali extraction, enzyme extraction, and composite extraction.

Alkali Extraction

Rice protein contains 80% alkali-soluble protein. Alkali extraction relies on the principle that alkali-soluble proteins dissolve in alkaline solutions. The alkaline solution loosens the dense structure of rice starch bound with rice protein, disrupts secondary bonds, especially hydrogen bonds, and promotes the separation of starch and protein by dissociating certain polar groups on the protein surface. After removing impurities through centrifugation, the pH of the supernatant is adjusted to the isoelectric point of rice protein, causing most proteins to precipitate. Alkali extraction is characterized by its simplicity, high extraction efficiency, good product color, and texture, making it widely used in industrial production due to its low cost. However, it has disadvantages such as a large solid-to-liquid ratio, significant consumption of alkali and water, difficulty in desalting purification, and potential safety hazards due to the formation of toxic substances during certain reactions.

Enzyme Extraction

Enzyme extraction involves treating rice with proteolytic enzymes to separate rice protein from other components and increase its solubility for easier extraction. It can be categorized into protease extraction and non-protease extraction. Protease extraction utilizes enzymes like acidic protease, neutral protease, alkaline protease, and composite protease. Among them, alkaline protease is reported to be the optimal enzyme for rice protein extraction. Another approach in enzyme extraction is to remove non-protein components from rice using appropriate enzymes, such as amylase, during starch extraction. Enzyme extraction conditions are mild, preserving nutrients and enhancing protein digestibility. However, the high cost of enzyme preparations poses a challenge to industrial production.

Composite Extraction

Due to the drawbacks of both enzyme and alkali extraction methods, current research is shifting towards composite extraction to improve product quality and yield while reducing production costs.

Development and Utilization of Rice Protein

Bioactive Peptides of Rice Protein

Rice peptides, obtained by hydrolyzing rice protein molecules through methods such as acid, alkali, and protease treatment, are small peptide molecules. Acid and alkali methods are no longer used due to environmental and safety concerns, with enzyme methods being the most common for rice peptide processing. Enzymes used in peptide processing come from various sources such as plants, animals, and microorganisms, including papain, bromelain, ficin, pepsin, trypsin, neutral protease, alkaline protease, acid protease, and flavor protease. Rice peptides exhibit various physiological benefits, including antioxidant, anti-aging, blood pressure reduction, lipid-lowering, immune modulation, and flavor peptide effects. For example, a peptide named oryzatensin, isolated and purified from pancreatic trypsin hydrolysate of rice clear protein, has shown activities such as inducing contraction of guinea pig ileum, anti-morphine, and immune modulation.

Nutritional Supplements

Due to its low antigenicity and high nutritional value, rice protein is widely used in the development of high-protein, low-allergenic infant formula rice powder. Rice protein, being gluten-free, is suitable for individuals intolerant to wheat or those with allergies or gastrointestinal diseases. Rice concentrate protein can also serve as a supplement for patients with reduced protein intake or impaired protein digestion, helping to maintain nitrogen balance. Additionally, rice protein can aid in the treatment of digestive ulcers, osmotic diuretics, and assist in trauma recovery.

Edible Films

Edible rice protein films are environmentally friendly packaging materials with excellent freshness, gas barrier, oil resistance, and moisture-proof properties. They meet the requirements of high-quality and safe food packaging, addressing environmental concerns related to non-renewable packaging materials. Rice protein films have the potential to carry active ingredients, such as anti-browning agents, colorants, flavors, nutrients, and antibacterial compounds, extending shelf life and reducing the risk of pathogen growth on food surfaces.

Food Additives

Enzyme-treated rice bran protein, with improved solubility, foaming properties, and emulsification characteristics, especially when treated with endoprotease and exoprotease, yields protein hydrolysates with appropriate peptide chain lengths and functional properties. These hydrolysates can be used as food emulsifiers, foaming agents, and nutritional enhancers.

Instant Protein Powder

The poor water solubility of rice protein, especially rice bran protein, limits its application in beverages and nutritional protein powders. To enhance the solubility of rice protein, modifications for increased solubility are necessary. Solubility enhancement refers to increasing the solubility of rice protein while maintaining a lower degree of hydrolysis to prevent excessive protein breakdown. Common methods for solubility enhancement include glycosylation and enzymatic modification.

Rice Protein Feed

By-products of rice starch can be used as feed-grade rice protein powder, providing nutritional benefits for livestock and poultry, promoting disease resistance, and improving feed utilization efficiency. In recent years, there has been increasing recognition and in-depth research into the functional properties of rice protein and rice peptides within the academic community. From a health perspective, rice protein and peptides have been found to have various physiological effects, such as lowering blood cholesterol, promoting fat metabolism, facilitating calcium absorption, reducing blood lipids, regulating blood pressure, promoting sleep, enhancing memory, delaying aging, regulating the immune system, improving microcirculation, and thereby enhancing physical fitness and disease resistance. Moreover, research indicates that rice peptides with molecular weights mainly concentrated in the range of 200-2000 Dalton exhibit excellent antioxidant and anti-aging effects. It is believed that in the future, the application of rice protein in various fields such as food, health products, cosmetics, and feed will become increasingly widespread.

In the realm of rice protein, ETprotein stands out as a trusted provider, offering top-notch quality and innovative solutions. Their rice protein not only caters to the nutritional needs of infants and individuals with dietary restrictions but also contributes to sustainable packaging through edible films. With a commitment to excellence and a focus on bioactive peptides, ETprotein transforms rice protein into a versatile ingredient with various health benefits. Explore the possibilities with ETprotein – your go-to source for premium rice protein solutions that align with both health and environmental consciousness.