Study On The Color Changes In The Brewing Process Of Chinese Wolfberry Wine

Wolfberry wine is a wine with Chinese wolfberry as the raw material of the fermentation. Because of its rich in main color substances carotenoids and polyphenols, they are easy to be affected by the outside worldit to produce oxidation or degradation reaction, resulting in the color of Chinese wolfberry wine in the brewing process is prone to change. The wolfberry fruit as raw materials, mainly to study the Chinese wolfberry wine in pre fermentation, fermentation and aging period of polyphenols, carotenoids changes.At the same time, the effect of various factors to find out the fermentation system influences the level of carotenoid, has carried on the simulation study, to reveal the main cause of color change of Chinese wolfberry wine.Using high performance liquid chromatography, gas chromatography and other methods, and use origin and SPSS statistical software to analyze the experimental results.The main contents of this paper were as follows:(1) Before fermentation:Carotenoids was appropriate stable in the natural conditions and proper pectinase treatment, but with the time prolonged partial degradation. Phenolic acids at low pH, oxygen and appropriate pectinase treatment was stable, obvious color change did not occur, but at room temperature, with the storage time extension of phenolic acid and its oxidative condensation content decrease. SO2 had a protective effect on carotenoids and phenolic acids, which can effectively prevent the change of color.(2) During the fermentation process:Yeast fermentation produced ethanol while producing other metabolites, in which the organic acid causeed the pH to decline, and the low pH can prevent the fermentation liquor from oxidizing and browning. The content of phenolic acids in each monomer decreased as a whole, and the content of phenolic acids was more severe with the prolonging of fermentation time. The carotenoid content is downward trend, the change of zeaxanthin is more complex.(3) Fermentation simulation results:temperature and carboxylic acids were the main factors that affect the degradation of carotenoids. Followed by aldehydes and ketones, esters and alcohols were minimal impact solution.(4) Influence of aging conditions:the main effect of color change of Chinese wolfberry wine in the aging process factors of light, temperature and oxygen, and non-enzymatic browning mainly. Low temperature and light, full storage was conducive to prevent the occurrence of browning reaction of medlar wine during aging.