Optimization Of Processing Technology And Antioxidant Activity Of Lycium Ruthenium Fruit Vinegar

As a kind of nutritious small berry food,Lycium ruthenicu is a high-quality raw material for processing into functional health food.It has always been favored by consumers and favored by the market.However,there are relatively few researches on its application and development at present.In this topic,through the determination of anthocyanin content and its stability in Lycium ruthenicum,the research on the content of anthocyanin in Lycium ruthenicum with higher anthocyanin content was carried out to optimize the fermentation conditions of fruit vinegar.The antioxidant properties were compared with those of hawthorn vinegar and Qianhe zero-added pit vinegar,in order to provide a certain theoretical basis for the development and utilization of Lycium ruthenicum.The test results are as follows:（1）Through the determination of anthocyanin content and stability of Lycium ruthenicum in different regions of Xinjiang,the results show that the content of anthocyanin in the dried fruit of Lycium ruthenicum from different regions is quite different,and the content of anthocyanin in the dried fruits of Hetian,Shihezi and Aksu is quite different,the contents of anthocyanins were 14.7 mg/g,26.12 mg/g,and 9.64 mg/g,respectively;the effect of light conditions on the stability of anthocyanins in Lycium ruthenicum was slightly higher than that under dark conditions;the anthocyanins have different heat resistance,and the maximum heating temperature cannot be higher than 60℃;Al³⁺can protect and enhance the color of anthocyanins,while K⁺and Ca²⁺will reduce the stability of anthocyanin solution;the mass concentration is 0.5～1.5 g/100m L of sodium chloride has a protective effect on anthocyanins;the p H value of the solution has an obvious effect on the stability of the anthocyanin.In order to keep the anthocyanin from Lycium ruthenicum stable,the p H value of the solution should be kept below 6;sucrose and glucose with a mass concentration of less than 1.0 g/100 m L can significantly improve the absorbance of anthocyanin solution,while ascorbic acid will reduce the stability of anthocyanin solution.（2）Through single factor test,orthogonal test and response surface test,the optimal process conditions for alcoholic fermentation and acetic fermentation of Lycium ruthenicum vinegar were determined.The most suitable strain for alcoholic fermentation is wine cider yeast,the addition of dried Lycium ruthenicum was15%,and the optimal process conditions for alcoholic fermentation were initial sugar content of 17%,fermentation temperature of 32℃,and inoculum volume of 4%.The most suitable strain for acetic fermentation is Shanghai Brewing 1.01 Acetobacter,the optimal process was fermentation temperature of30℃,inoculum volume of 7%,and liquid filling volume of 42 m L/250 m L.The acidity of the obtained Lycium ruthenicum vinegar is 3.763 g/100 m L,and the anthocyanin content is 0.548 g/L.（3）By measuring the total phenolic and flavonoid content of Lycium ruthenicum vinegar,and comparing its antioxidant activity,the results obtained:the total phenolic content of Lycium ruthenicum vinegar,hawthorn vinegar,and Qianhe zero-added pit vinegar were 0.875 g/L,0.673 g/L,0.337 g/L,and the flavonoid contents were 0.650 g/L,0.565 g/L,0.263 g/L,respectively;the three vinegars were DPPH free It has good scavenging ability,ABTS free radical and hydroxyl free radical,and has high reducing ability.The correlation analysis shows that polyphenols and flavonoids have a significant effect on the antioxidant capacity of vinegar.Further,UHPLC-Q-TOF MS technology was used to analyze the antioxidant capacity of vinegar.A total of 58 kinds of polyphenols and their derivatives were identified by co-analysis of the three vinegars,including 22 kinds of flavonoids,11 kinds of phenols,9 kinds of cinnamic acid and its derivatives,etc.