Study On The Oxidation Of Chinese Rice Wine With Storage Process

In the process of Chinese rice wine aging, many chemical and physical changes will happen, leading to the improvements of wine quality, wine mouthfeel and wine fragrance. As a major kind of chemical reactions in the process of aging, the oxidation reaction exerts a significant effect on the process and result of wine aging. However, production enterprises occupy a lot of money and resources due to the slow natural aging process. As a result, it seems particularly urgent and important to study the changing regulation of interaction of each substance in the Chinese rice wine and discuss the improvement measures of Chinese rice wine aging process.This study tested the material contents in different vintages of Chinese rice wine and analyzed the main factors of oxidation reaction in the process of aging. Moreover, this study applied two kinds of oxidants and ultra-high pressure technology to treat new brewed wine, followed by testing the effects of these processing conditions on the material contents. This study also established an alkyd simulation system to analyze the influence of micro-oxygenation treatment and ultra-high pressure treatment on the content of acetaldehyde and ethyl acetate. Based on these results, this study preliminary discussed the improvement measures of Chinese rice wine aging process via improving the reaction speed of oxidation and esterification. The specific conclusions are as follows:(1) In the natural storage Chinese rice wine within five years, pH value and the contents of alcohol, total phenol and tannin were decreased year by year, while the contents of iron ion and total ester were increased year by year. The amount of oxygen and the contents of alcohol, iron ion and total phenol were the main factors of oxidation process from alcohol to aldehyde.(2) Hydrogen peroxide, as a strong oxidant, could greatly accelerate the process of wine oxidation reaction, which was accompanied by the ultra-high pressure treatment to enhance the esterification reaction, resulting in the acceleration of aging. When the concentration of hydrogen peroxide reached 18mg/L and the pressure 300 MPa maintained 20 min, the contents of total phenol, total acid and total ester were 0.783 g/L (close to that of natural storage for one year),4.68 g/L (equal to that of natural storage for five years),42.58 mg/L (approximate to that of natural storage for a year), respectively. Overall, the processed wine was equal to that of natural storage for one year.(3) Based on the physical and chemical index, the established alkyd simulation system could eliminate the interference of other organic compounds in oxidation reaction of wine, leading to getting the experiment data of oxidation process and esterification process intuitively and reliably.(4) This study suggested the following technological measures to accelerate the aging of Chinese rice wine through the test of the alkyd simulation system:a. Adding a reasonable amount of iron ions and polyphenols in wine filtration process and stirring properly will accelerate the coupling of phenol with quinone, resulting in the generation of hydrogen peroxide and acceleration of the oxidation process.b. In the condition of plenty of oxygen, it will be benefit for the promotion of oxidation reaction and esterification reaction in new brewed wine to treat the wine with ultra-high pressure processing timely.