Technology Optimization Of Lactobacillus Fermented Cherry Juice And Preparation Of Cherry Fruit Powder

With the improvement of health consciousness,people's consumption demand for beverage has also undergone a qualitative change,from "focusing on taste" to "function".Plant drinks are favored by consumers because of their natural,nutritional and safety characteristics,while fermented plant drinks are a new health drink,which can produce special flavor and improve quality after fermentation to meet people's pursuit of healthy diet,and have strong competitiveness in the market.Sweet cherry is rich in many kinds of vitamins and minerals.It has the functions of preventing cardiovascular and cerebrovascular diseases and anticancer.But its fresh fruit is not resistant to storage and easy to rot,so it needs to be processed to improve its added value.Juice is one of its processed products.In order to enrich the variety of cherry juice and enhance its functional activity,this project uses fresh cherry as raw material,Lactobacillus bulgaricus and Streptococcus thermophilus as 1:1 lactobacillus to ferment,optimize the optimal fermentation process,detect the changes of main components of cherry juice with and without fermentation,and evaluate the quality of fruit juice.The fruit juice was prepared into convenient fruit powder,which provided theoretical basis for the deep processing and utilization of cherry.1.Determination of the best fermentation technology of cherry juice by Lactobacillus.Taking SOD activity,sensory evaluation and superoxide anion radical scavenging rate as comprehensive evaluation indexes,the optimal fermentation process was optimized by single factor experiment and orthogonal experiment.The results showed that the optimum fermentation conditions were: the inoculation amount of mixed lactobacillus was 2.5%,fermentation temperature was 35?,and fermentation time was 24 hours.The cherry juice prepared under this condition had an SOD activity of 2605.263 U / m L,a superoxide anion radical scavenging rate of 82.7%,and a sensory score of 95 points.The changes of the main components in cherry juice before and after fermentation were detected,and it was found that the content of flavonoids,phenols and anthocyanins in cherry juice after fermentation of lactic acid bacteria increased significantly,but total sugar and ascorbic acid content increased but not significant.2.The preparation of cherry fruit powder: the cherry juice with and without fermented was prepared cherry fruit powder by spray drying.The drying process was optimized by single factor experiment and orthogonal experiment with the powder yield as the evaluation index.The results showed that the best conditions for spray drying were: air inlet temperature was 190?,material flow was 600 m L/h,and the ratio of maltodextrin and cherry juice solids was 3:7.Under these conditions,the yield of cherry powder was 17.79 %.The fruit powder was reconstituted,and the main components and antioxidant activity of the cherry juice before and after spray drying were detected.The results showed that the content of phenols and total sugar increased significantly,while the content of flavonoids,anthocyanins,ascorbic acid and organic acids decreased,the antioxidant capacity decreased.