Patent literature often reports that chemical synthesis has high cost and low yield, and dangerous solvents and even toxic solvents are used in the production process. Therefore, GABA prepared by chemical synthesis can not be used in food, nor can it be considered as a natural food additive.
Biosynthesis is a safe and low-cost method. In the early research, GABA was produced by fermentation with Escherichia coli as the production strain, and the fermentation medium was bran hydrolysate, corn steep liquor, peptone, minerals and so on. In the fermentation process, L- glutamic acid is converted into GABA by decarboxylase in Escherichia coli, and then GABA products are obtained by separation and purification. However, if food development is to be carried out, there are undoubtedly various safety problems in the use of Escherichia coli. According to the latest research report and patent literature, some microorganisms with high safety, such as lactic acid bacteria, yeast and Aspergillus, have been applied to the preparation of GABA food, which makes the biosynthetic GABA products can be used as ingredients of advanced functional health food.
manufacturing method
There are synthesis method and fermentation method. 1. The synthetic method is prepared by ring-opening of pyrrolidone. Lime is digested with distilled water to form lime milk, pumped into the hydrolysis reactor, and pyrrolidone is added, and the temperature is raised to 125- 130℃, the reaction pressure is kept at 0.29MPa, and the reaction time is kept at 10- 14 hours. After the reaction, the temperature was reduced to 30℃, and the product was discharged, filtered and washed with distilled water. Ammonium bicarbonate was added to the filtrate until calcium ions could not be detected, then activated carbon was added to decolorize at 80℃ for 30 minutes, filtered at 60℃, washed with distilled water, washed with filtrate, concentrated under reduced pressure at 60℃ until crystals were precipitated, added with ethanol, cooled, filtered and dried, and the finished product was obtained with a yield of over 85%. 2. The fermentation method uses Escherichia coli as a strain. The fermentation medium is bran hydrolysate, corn steep liquor, peptone, magnesium sulfate and sodium chloride. Soybean oil was used as defoamer, the dosage was about 0. 1%, and the fermentation unit was about 100 enzyme unit /ml fermentation broth. In the refining process, L- glutamic acid is converted into γ-aminobutyric acid by decarboxylase of Escherichia coli, which can be dissociated into cations in aqueous solution. Ion exchange, ammonia elution, extraction, resin purification, concentration, crystallization and drying are carried out with strongly acidic styrene cation exchange resin to obtain the finished product. As an active factor, γ -aminobutyric acid has good physiological activity and broad application prospects in functional foods. It is reported that tea and rice germ can enrich GABA through natural fermentation. In addition, natural food raw materials such as bean products, tomatoes and Chlorella can enrich GABA through processing. At present, many Japanese companies and research institutes are engaged in the development of this field. Although GABA is widely distributed in nature, it undoubtedly needs a lot of work to develop it into a functional factor of health food. The content of GABA in animal and plant tissues is low, for example, the content in soybean leaves is only 0.04μg/g fresh weight, so it is not feasible to extract GABA directly from animals and plants as food ingredients, mainly because GABA exists in a small amount and is difficult to separate.
As the development of food, we should not only have the idea of homology between medicine and food, but also distinguish the concepts of medicine and food. The application of γ -aminobutyric acid in food is not simply adding medicinal γ -aminobutyric acid, but starting from the source of preparation, using natural substances and adopting biotechnology methods to produce edible γ -aminobutyric acid which can be safely used in food and can be regarded as a natural additive. Firstly, GABA additives can be prepared from grain processing by-products. In the mid-1990s, Japan Rice Oil Chemical Company developed a health food additive named GABARICEGERM. Soon after, Japan Food Science and Technology Society reported the remarkable effect of this product in improving insomnia, depression and climacteric syndrome, confirmed various physiological functions of GABA, and pointed out that foods rich in GABA are functional foods. In China, at present, the development and utilization of rice germ is not sufficient, and the by-product of rice processing is rich in nutrition, but it is difficult to separate, so many rice mills leave it in rice bran as feed. In fact, the abundant rice germ resources are promising and can be further processed into various foods or food ingredients. Rice germ is rich in nutrients such as protein and minerals, and also contains a certain amount of GABA, but the content is very low, even after separation and concentration, it is still difficult to reach a higher content. If it is used as a basic raw material, the added value of rice germ can be greatly improved and the benefits can be increased by increasing the GABA content, enhancing the health care function and improving the flavor of the product through biotechnology.
Secondly, GABA additives can be biosynthesized by fermentation. That is to say, GABA preparation is produced by screening excellent and high-yield safe strains and purely applying microbial technology. At present, yeast and lactic acid bacteria are recognized as a kind of safe microorganisms. GABA is an ideal component of green food and organic food advocated by 2 1 century, and it is also an ideal health food and medicine for preventing and treating senile diseases. The human body ingests 30-50 mg of pure natural GABA every day, which can play an ideal health care role. Because the dosage is very small, it can be matched with other plant extracts to make nutritional supplements in the form of capsules, soft capsules, tablets, powders and the like suitable for various consumer groups. Can be used for health food and common food.
Third, develop functional dairy products. The consumption of dairy products is very large, and it is also one of the most common consumer goods. The dairy products fortified with GABA can be said to be an ideal combination, because rich GABA can further enhance the functionality of dairy products and make them more competitive. However, strengthening GABA dairy products is only an idea at present. The application of GABA in milk powder has been reported in foreign patent literature, but it is rarely used in other varieties, and a lot of development work is needed.
Fourth, the application in sports food. Fatigue caused by work, study and exercise is a physiological phenomenon. Sports drinks prepared with GABA can meet the needs of high-intensity exercise and have become popular abroad.
Fifth, it is applied to baked goods. With the implementation of the market access system, the baking industry has entered a "threshold" improvement. In recent years, developed countries such as Europe and America have put forward the development trend of baking food ingredients with the theme of green health. Bread has developed into a worldwide popular food. Adding a small amount of GABA to bread can effectively reduce the incidence of cardiovascular diseases. Adding proper amount of GABA to cookies and cakes can make healthy food suitable for the elderly or children.
Sixth, the application in beverages. In recent years, the annual output of beverages in China has increased at an annual rate of more than 20%, and the beverage market has become one of the fastest growing markets in China's food industry. Consumers' demand for natural, low-sugar and healthy drinks has promoted the rise of new varieties. Functional drinks, tea drinks and juice drinks with GABA will be favored by more consumers. In 2007, Coca-Cola Company of Japan introduced the GABA functional drink "AQUARIUSSHARPCHARGE", which is geared to the public and has the functions of relaxation and anti-tension.
Uses: Used in biochemical research and medicine to treat various diseases caused by hepatic coma and cerebrovascular diseases. Pharmaceutical intermediates. 4-aminobutyric acid has the function of reducing blood lipid, and is suitable for treating and preventing various types of hepatic coma. It can be used to treat poliomyelitis and cerebral hemorrhage, and can also be used as an antidote for gas poisoning. It is also used in biochemical research and organic synthesis. On September 27th, 2009, the Ministry of Health approved γ -aminobutyric acid, colostrum basic protein, * * conjugated linoleic acid, * * glyceride of conjugated linoleic acid, Lactobacillus plantarum (strain number ST-Ⅲ) and Eucommia seed oil as new resource foods, and γ -aminobutyric acid entered a new era in China. The main domestic GABA producers are Zhejiang Yiwan Biotechnology Co., Ltd. and Anhui Frye Hi-Tech Co., Ltd.