Study On Preparation Of Jujube Powder Fermented By Compound Probiotics And Its In Vitro Gastric And Intestinal Digestion Simulation

The probiotics fermented jujube powder was prepared by spray drying method.The prepared juj ube powder has the advantages of low water content,good nutrition preservation,low bulk density and low cost.The main research results are as follows:1.Study on Difference of Quality Characteristics of Jujube PuLp Fermented by Different Probiotics.In this study,Lactobacillus plantplanum NXU-190035 and Bacillus coaguLants NXU-19034 were used to compound fermented jujube puLp.On the basis of single factor experiment,the response surface analysis was carried out for the compound fermented jujube puLp with inocuLation amount,strain ratio,primary fermentation time as independent variables and sensory evaluation as response value.The resuLts showed that the optimal fermentation parameters of jujube puLp with compound probiotics were as follows:Lactobacillus plantalum NXU-190035:Bacillus coaguLans NXU-34 was 4:1,and the total inocuLation amount was 3%.Lactobacillus plantarum NXU-190035 was inserted into jujube puLp for fermentation for 6 h,and then inserted into Bacillus coaguLans NXU-34 for secondary fermentation,and the total fermentation time was 18 h.The contents of flavonoids,polyphenols,polysaccharides and total acids were 1.36±0.03 mg/mL,1.24±0.04 mg/mL,14.50±0.20 mg/100mL and 3.82±0.12 mg/mL respectively.2.Study on fermentation technology of jujube powder by probiotics by vacuum spray drying.With fermented jujube puLp as raw material and air inlet temperature,atomization flow rate,peristaltic pump speed and the amount of defatted milk powder as independent variables,the response surface optimization was carried out based on single factor experiment,and the powder yield and sensory evaluation were taken as response values.The technological parameters of probiotics fermentation of jujube powder with higher viable bacteria number and sensory evaluation were as follows:Under the inlet temperature of 152?,peristaltic pump speed of 21%,atomization flow rate of 475 L/h and additive amount of fat and milk powder of 2.54%,the measured powder yield,sensory evaluation of 95.2,water content of 4.15%,buLk density of 0.251 g/mL and viable bacteria number of 1.82×109 CFU/g were 39.15%.3.Study on the external simuLation digestion characteristics of jujube powder fermented by probiotics.With jujube powder prepared from unfermented jujube puLp as blank control,the contents of flavonoids,polyphenols,dietary fiber and antioxidant of probiotics jujube powder at different stages of simuLated digestion in vitro were measured,and the bioavailability of nutrients during simuLated digestion in vitro was studied.During the whole digestion process,the content of total flavonoids,total polyphenols,free radical scavenging capacity ·OH,DPPH· and ABTS+· were decreased by 15.22%,1.19%,8.16%,2.69%and 3.15%respectively.The content of total flavonoids,total polyphenols,free radical scavenging capacity ·OH,DPPH· and ABTS+· were decreased by 5.56%,5.08%,4.97%,1.34%and 1.64%respectively.The dietary fiber content was basically unchanged,which was consistent with the resuLts of in vivo digestion study.The live count of probiotics in the fermented jujube powder was more than 107 CFU/mL,which was higher than that in the fermented jujube powder and liquid of lactobacillus plantalum NXU-190035 in the control group and the blank control group.In conclusion,the free radical scavenging ability and bioavailability of flavonoids and polyphenols of probiotics fermented jujube powder were better than that of unfermented jujube powder.Bacillus coagulans had strong resistance to stress,and the probiotics in the jujube powder fermented by probiotics had better resistance to stress than the probiotics in the jujube liquid.So probiotics fermented jujube powder is better than unfermented juj ube pulp jujube powder.