Research and Development Progress of Functional Rice and Its Food Products
Functional rice refers to rice products that regulate human physiological functions, are suitable for consumption by the general population, and are not intended for the treatment of diseases. In addition to containing the seven major nutrients necessary for human growth and development - protein, fat, carbohydrates, vitamins, minerals, water and fiber - functional rice also contains certain special components that regulate and balance human physiological functions. It can enhance physiological defense mechanisms, prevent specific diseases, delay aging, and control physical strength and energy status.
1. Processing Methods of Functional Rice
(1) Biotransformation method. The so-called biotransformation method uses microbial synthesis and transformation (such as selenium-germanium-enriched yeast), or plant seed germination transformation (such as selenium-germanium-enriched bean sprouts, brown rice sprouts, malt), through their enrichment and biochemical action, converting inorganic salt forms into organic components similar to natural forms. These organic components are basically non-toxic, have high physiological activity, are easily absorbed by the human body, and their off-flavors are modified. Then, corresponding techniques are adopted to develop functional rice rich in certain physiologically active components. For example, selenium-germanium-enriched rice processed by this method shows significantly increased content of selenium, germanium, protein, vitamin B1 and vitamin B2. It is an excellent functional food base material, and also contains various physiologically active components abundant in yeast and bean sprouts (or brown rice sprouts, malt), thus its physiological regulatory function tends to be more complete.
(2) Spraying method. This method extracts functional food components from food raw materials, prepares them into functional food base materials, and then adds them to rice to produce functional rice. During processing, some liquid or water-soluble, odorless functional food base materials are formulated into a solution and sprayed onto the rice. For example, a functional coating-processed rice device can be used, that is, adding a protein or polysaccharide aqueous solution containing functional components to the surface of rinse-free rice, using this solution as a coating solution
added to the surface of rinse-free rice, and producing functional coating-processed rice with balanced nutritional composition in a short time.
(3) Molecular biology and biological genetic engineering method. Developing functional rice is a systematic project that involves multiple disciplines such as nutrition, physiology, microbiology, biochemistry and food engineering. Using traditional breeding methods, gene mutation methods, or high-tech techniques such as molecular biology and biological genetic engineering to research and develop antiviral and anti-allergic functional rice products can prevent certain viral infections and allergic diarrhea in children.
2. Food Categories of Functional Rice
(1) Rice starch functional foods. Rice starch is a major raw material for numerous functional foods. Rice starch from different sources, or even the same source, often has vastly different characteristics before being processed and modified by physicochemical methods. The creation of new natural starch germplasm resources with special functions will provide irreplaceable important raw materials for the development of new foods. Ricemic, a rice product from the Southern Regional Research Center of the United States Department of Agriculture, is a successful example. They used rice flour as raw material, first separated the protein, and then used heating and enzyme engineering processing techniques to develop modified rice starch products capable of 100% delaying digestion, and capable of 50% accelerating digestion and 50% delaying digestion. Clinical trials have confirmed that this food can effectively reduce glycemic load, and it is expected to become a new type of food for diabetic patients.
Fat substitutes prepared from rice starch are very suitable for processing yogurt and dairy products that partially replace cream. They possess both the appearance and mouthfeel of cream, and do not cause excessive energy intake. The development of such products will undoubtedly bring good news to the growing number of obese patients. Belgian scientists have officially applied modified starch to the production of cream-free cheese, low-fat ice cream, fat-free margarine, sauces and salad dressings, achieving considerable economic and social benefits.
(2) Rice bran health foods. Rice bran accounts for about 5%-5.5% of the mass of paddy rice. China's rice bran resources are very abundant, with annual output reaching over 10 million t, but most rice bran is not rationally utilized. In addition to containing carbohydrates, fats, proteins and vitamins, rice bran also contains nearly 100 kinds of bioactive factors with various functions. Therefore, research and development on rice bran at home and abroad is quite extensive and in-depth.
Rice bran oil. Rice bran oil not only contains over 80% unsaturated fatty acids such as linoleic acid, but is also rich in nutrients such as oryzanol, vitamins, phospholipids and plant sterols. Therefore, rice bran oil is a healthful edible oil, and its nutritional value exceeds that of soybean oil and rapeseed oil. In a special report, the American Heart Association pointed out that rice bran oil can effectively alleviate heart and brain diseases, with its effectiveness manifested as reducing the concentration of low-density cholesterol in the blood and raising high-density cholesterol. Studies have shown that after consuming rice bran oil for 1 week, human serum cholesterol levels can decrease by 17%. In recent years, rice bran oil has been selling well in European and American markets, with its price higher than traditional vegetable oils such as peanut oil and soybean oil, and it is quite favored by consumers. In Thailand, a major rice-producing country, over 40% of rice bran output is used to produce rice bran oil as cooking oil. In Japan, the price of defatted rice bran is higher than that of full-fat rice bran, which is conducive to the development of the rice bran oil industry.
Rice bran nutrients, nutritional beverages and nutritional fiber. Utilizing the rich and comprehensive nutritional components and dietary fiber in rice bran to develop nutritional and health foods is the earliest researched and most numerous category of rice bran foods. For example, the rice bran nutrients (RiceXTMSol-ubles) and rice bran nutritional fiber (RiceXTMFibercomplex) produced by the American company RiceXTM.
Rice bran polysaccharides. Using different extraction processes, various rice bran polysaccharides can be obtained, such as RBS, PBF-P, RBF-PM, MDP, RON, MGN-3, etc. They all have significant anti-tumor, immune-enhancing and blood sugar-lowering bioactivities and health functions.
Rice bran ceramide. Rice bran ceramide is a functional ingredient extracted and refined from rice bran, rice germ and other raw materials. Ceramide has effects such as whitening, moisturizing and alleviating symptoms of allergic dermatitis on the skin. Currently, in the Japanese market, there are powder-type and liquid-type products containing over 0.3% rice bran ceramide, which are used as important raw materials for beauty foods. Previously, ceramide products were mainly obtained from @#@245@#@, and the products were expensive.
Rice bran anti-cancer IP6 health products. IP6 is a trace component derived from phytic acid in defatted rice bran, and has the function of inhibiting the formation of lipid peroxides in the human body. In recent years, foreign studies have found that IP6 also has effects such as enhancing immunity and anti-cancer. The U.S. FDA has confirmed its efficacy, and an IP6 market scale has already formed in the United States, with more than 100 kinds of products. For this reason, the Japanese company Tsukino Food Co. has launched products such as "IP6 rice bran extract" and "IP6 extract beverage".
(3) Germinated brown rice products. Japanese scholars discovered that brown rice germ can produce large amounts of gamma-aminobutyric acid through its own decarboxylation reaction, and thereby developed rice germ foods rich in gamma-aminobutyric acid. In recent years, various germinated brown rice foods rich in gamma-aminobutyric acid have formed series in Japan including rice products, convenience foods, beverages and pastries. Germinated brown rice products include vacuum-packed germinated brown rice, various convenience foods using germinated brown rice as raw material, beverages, and food additives with higher content of nutritional elements. Germinated brown rice and convenience foods are staple food products, and the market prospects in China, a major rice-consuming country, are very broad.
In summary, as the physiological effects of rice components are applied more extensively and deeply in clinical research and processing techniques are continuously explored, people will more widely and scientifically make full use of rice resources, further promoting the technological development of the rice processing industry, and ultimately making the rice processing industry a new type of agricultural product processing industry capable of producing high-value-added products.