Preparation Of Freeze-dried Fermented Fruit And Vegetable Crisp And Study In Vitro Function

In recent years,complex fruit and vegetable products with rich nutrition and unique flavor have become popular health foods.Kefir belongs to probiotic fermented milk,which is produced by fermenting Kefir pellets.At this stage,the development of Kefir’s new products is mainly based on the replacement of raw materials.For example,replacing cow’s milk with some blended milk or vegetable protein milk for fermentation can obtain new Kefir products with unique flavors and novel tastes.In this paper,with apple pulp,ketchup and sea buckthorn juice as raw material,kefir fermenting compound fruits and vegetables,adding a certain amount of active substances such as inulin,fructooligosaccharides and barley green,then a leisure health product was made by freeze—drying in vacuum.Freeze-dried products were made into different concentration gradients dilutions,and the fermented group and the unfermented group were used as controls to analyze and determine the indexes of hypoglycemic,lipidlowering and antioxidant in vitro.This study provids a theoretical basis for the industrial production of Kefir fermenting compound fruits and vegetables freeze-dried products.The findings are as follows:1.With apple pulp,ketchup and sea buckthorn raw juice as raw materials,the effects of different raw material ratios on the combined scores of solid content,flavonoid content and sensory scores of composite fruit and vegetable pulps were studied.Through the single factor test and orthogonal test,the optimal blending combination of fruit and vegetable pulp was determined to be 70.0 g of apple pulp,20.0 g of tomato sauce,and 17.5 g of sea buckthorn juice.2.With apple-tomato-sea buckthorn compound fruits and vegetables as raw materials,inoculated with Kefir bacteria for fermentation.Through single-factor and response surface experiments,the effects of fermentation time,inoculation amount,and fermentation temperature on the total acid content and the number of live bacteria of compound fruits and vegetables were studied to optimize the best fermentation process.The results showed that the best parameters of Kefir fermenting composite fruits and vegetables were 46.4 h fermentation time,8.0% inoculation amount,and 31 ° C fermentation temperature.Under this fermentation condition,the total acidity of the fermented fruits and vegetables was 10.72 g / L,and the number of live bacteria was 11.56.lg CFU / m L.3.The above-mentioned fermented and unfermented composite fruit and vegetable pulps are respectively mixed with active substances such as inulin,fructooligosaccharides and chlorophyll,and then made those into the freeze-dried fruit and vegetable crisp products by vacuum freezedrying technology.Measure the viable count of the lyophilized fermentation product,and then the freeze-dried products were made into different concentration gradients,and compared with the fermented group and the non-fermented group,and the five methods of α-amylase inhibition rate,sodium taurocholate adsorption amount,DPPH radical scavenging rate,hydroxyl radical scavenging rate,and iron reducing power were used to study the effect of fermentation process on the hypoglycemic,lipidlowering and antioxidant activity of composite fruits and vegetables influences.The results showed that the survival rate of the live bacteria count of the fermentation product after vacuum freeze-drying was 83.5%;Both the unfermented group and the fermented group showed certain activities of reducing glucose,lipid and antioxidant activity,and the fermented group had higher glucose,lipid and antioxidant capacity than the unfermented group.Therefore,Kefir was put into compound fruits and vegetables for fermentation to fully exert its probiotic function,and the whole system’s hypoglycemic,lipid-lowering and antioxidant activities were improved.