Study On Processing Technology And Antioxidant Activity Of Fruit Vinegar Of Date Palm

Date palm,also known as phoenix, is a common fruit in west Asia and Africa. And it is also a staple food in the middle east. At present, people are mainly eat dried date palms.And the data palm is lack of high value-added products. The sugar content of data palm is high, with data palm as vinegar fermentation raw materials, not only can expand the types of fruit vinegar products, but also for the deep processing of new ideas. This paper conducts a systematic study of data palm juice process, alcohol fermentation and acetic acid fermentation process parameters, the optimum process parameters of data palm vinegar preparation were determined, and the antioxidative effect in vitro was studied.1.Optimization of extracting date palm juiceOn the basis of single factor experiment, orthogonal test based on the juice yield, the optimal processing parameters are palm juice rate: enzyme concentration was 0.06%; the ratio of material to liquid I 1:5; enzymolysis time 4 h; enzymolysis temperature is 45?,the highest juice yield is 84%.2.Optimization of alcohol fermentation by orthogonal test and response surface methodThe single factor experiment was carried out to obtain the optimum process parameters, and the orthogonal test was used to investigate the significance of the factors.And with the response surface experiment to optimize the process parameters of alcohol fermentation of vinegar date palm. The best process of alcohol fermentation parameters for date palm vinegar 0.03% inoculation amount, temperature 24.67?, the initial sugar concentration is 21.85%, the theoretical alcohol was 9.12%, and the validating alcohol was 9.11%.3.Optimization of acetic acid fermentation by orthogonal test and response surface methodThe single factor experiment was carried out to obtain the optimum process parameters, and the orthogonal test was used to investigate the significance of the factors.And with the response surface experiment to optimize the process parameters of data palm fruit vinegar acetic acid fermentation. The best process conditions were obtained by using Design-Expert 8 to test the data. The inoculation rate was 0.02%, the temperature was about 28? the initial alcohol content was about 7.78%, the theoretical acetic acid yield was 7.26%, and the validating acetic acid yield was 7.32%.4. Antioxidant activity of date fruit vinegarThe content of total phenolic acid in date palm vinegar was determined, and in vitro antioxidant activity of date palm vinegar samples was also studied. The results showed that the total phenolic acid content of fruit vinegar was 1.44mg/mL, and it had significant scavenging effect on free radicals. When the concentration is more than 4%, vinegar of hydroxyl radical scavenging rate was 100%; when the concentration of 8%, removal of vinegar on the DPPH radical reached 97%; when the concentration of 40%, vinegar on ABTS+ radical scavenging rate reached 92%; at the same time, the date palm vinegar has a strong reducing power to Fe3+.