The development of Chinese liquor depends on technological progress. The combination of traditional Chinese and American traditional techniques and modern science and technology has done a lot of work in transforming traditional techniques, especially the application of “artificial old man†in microbial technology innovation. Liquor is promoted to the whole country. Subsequent research has deepened microbial technology into enzymology research. On the basis of the National Natural Science Foundation of China, which is based on the "Biosynthesis of Ethyl Acetate Esterification and Enzymatic Properties", the authors and co-workers have studied the application of innovative esterase technology on Chinese liquor. An innovative achievement is of great significance for improving the quality of Chinese liquor and developing ecological food.
Red song is an invention in ancient China. Red yeast is used in wine making, brewing food, medicine, etc. Today's application to Monascus is highly valued internationally. In recent years, many international conferences have been held. The lipid-lowering drug containing Monacolin produced by Monascus is an example involving food safety and ecological environment. In Europe, natural monascus pigment has been used as a coloring agent for fermented sausages, replacing other chemical pigments and has antiseptic effects. The authors and other research results of red esterification enzymes were considered to have filled a gap in the study of Monascus in an international symposium on the culture and application of Monascus in Toulouse, France. The esterification enzyme biosynthesis of scent ester technology will be an inevitable trend in the production of liquor in China's liquor production towards ecological production today.
1, esterification bacteria and esterase
Esterified bacteria are not the name of microbial taxonomy, but a generic term for specific microorganisms that have special functions of acid and alcohol esterification. Esterase is also not an enzymatic term. It should be a general term for lipase and esterase - lipolytic enzyme
1.1, sputum-type red yeast
The author of the esterification bacterium M-101, etc., found a functional bacterium capable of producing aroma in the microbial strain of the sputum type Daqu. The bacteria were on the malt agar plate. The colonies were white and felt-like. After 3 days, the colonies were grayish white with wrinkles. The microscopic colonies were separated and separated by a diameter of 3 to 9 μm. Containing oil droplets, 5d cultured a large number of quilts, spherical shape, size 6 ~ 9μm, conidia pear type or round, single or chain, size 5 ~ 10μm. The liquid culture in the wort and synthetic medium produced a small amount of pigment, and a large amount of red pigment was produced in the corn starch medium, which was identified as Monascus Fulginosus M-101 strain.
1.2, red yeast lipase and esterase properties
Studies have found that lipase and esterase produced by Monascus strain M-101 exist simultaneously, but their enzymatic properties are different. In terms of temperature, the esterase temperature reaction range is wide, the temperature curve is gentle; the lipase temperature is narrow, and the curve reaction is narrow. Both enzymes showed high heat resistance in thermal stability, and 100% retention at 45 ° C for 24 h, but at higher temperatures, it showed that esterase heat resistance was higher than lipase, pH effect The range of lipase is wide, the reaction range of esterase is narrow, and the stability of pH-stabilized esterase and lipase is 100% under certain conditions.
2, acid alcohol esterification and white wine flavoring
The main component of Luzhou-flavor liquor is ethyl hexanoate. The fermentation of hexanoic acid in sputum is produced by the production of hexanoic acid bacteria, while the synthesis of ethyl hexanoate from hexanoic acid depends on the action of ester-producing bacteria. The bacteria has this function, and now only the new esterification enzyme technology, the exogenous ester to produce the ester fragrance liquid, can be used for the production of Luzhou-flavor liquor, which can improve the quality of the product, improve the quality of the wine, shorten the fermentation cycle, and it is more suitable for the north. Production of Luzhou-flavored wine in short fermentation period. Others can be used in liquid fermentation or solid-liquid combination to produce Luzhou-flavor liquor.
Esterase technology includes enzyme-producing strain culture, enzyme production conditions, and esterification process control. The esterification enzyme technology theoretically produces ethyl hexanoate, which is basically an enzyme reaction in an organic solvent, and an acid and an alcohol are enzymatically synthesized into an acid ester, and the enzyme has a plurality of synthetic functions. If ethyl hexanoate is enzymatically synthesized from hexanoic acid and ethanol, ethyl lactate is synthesized using lactic acid or ethanol as a substrate. The production of acid and alcohol esterified ester scent liquid oxime esterification liquid 有 depends on the esterification enzyme.
Gansu Minxi Lishui Wine Group introduced this technology at the end of 2003. Now it has produced ethyl hexanoate biosynthetic ester liquid. The content of ethyl hexanoate in the synthetic ester liquid is calculated as ester content in 100ml ester liquid: esterification The amount of 10d raw ester was 1080mg, 30d was 2370mg, 60d was 4180mg, and 90d reached 7230mg level. According to the factory, the currently produced ester scent has been used in finished wines, and the low-grade wine cellar is considered to be significantly better than the purchased spices. The main advantage is that the wine has a strong natural feeling, sweet and strong, and the main body is outstanding. In addition to the fragrance, the ester scent is also planned to be used in the production of white wine to enhance the scent of traditional liquor, to lose the scent of liquor, to combine solid and liquid to prepare wine and fragrant.