复合乳酸菌发酵蓝莓果汁的工艺优化及功能活性研究OA

[Objective]The effects of the optimal processing technology for blueberry juice fermented with lactic acid bacteria on antioxidant activity and in vitro bioavailability of phenolic compounds in blueberry juice were investigated to provide a reference for development of functional blueberry deep-processing products.[Method]The optimal compound proportion of Lactobacillus plantarum,Lactobacillus rhamnosus and Lactobacillus fermentum for fermentation of frozen blueberries from Majiang County,Guizhou,was determined.The viable bacteria count and sensory evaluation of blueberry juice fermented with the optimal compound lactic acid bacteria proportion under different conditions of fermentation time(24 h,32 h,40 h,48 h and 56 h),temperature(28℃,31℃,34℃,37℃and 40℃),inoculum size(1.0%,3.0%,5.0%,7.0%and 9.0%)and solid-to-liquid ratio(3∶7,4∶6,1∶1,6∶4 and 7∶3)were analyzed by single-factor tests.The processing technology for blueberry juice fermented with multi-bacterial strains was optimized by an orthogonal test.The effects of lactic acid bacteria fermentation on antioxidant activity and in vitro bioavailability of phenolic substances in blueberry juice were studied by the free radical scavenging and in vitro simulated gastrointestinal digestion experiments.[Result]The optimized processing conditions for blueberry juice fermented with multi-bacterial strains were 5:3:2 of L.plantarum,L.rhamnosus and L.fermentum,5%inoculation size,solid-to-liquid ratio of 1:1 and at 37℃for 24 h.The viable bacteria count and sensory evaluation score of blueberry juice fermented under the optimized processing conditions were 8.86 lg(CFU/mL)and 96.79 respectively.Compared with the unfermented blueberry juice,the DPPH and ABTS free radical scavenging rate of the blueberry juice fermented under the optimal processing conditions increased by 34.36%and 32.49%,and the bioavailability of polyphenols,flavonoids,and anthocyanins increased by 29.23%,39.47%and 43.83%respectively.[Conclusion]The fermented blueberry juice under the optimized processing conditions has the advantages of delicate taste,uniform texture,delicious with slight sweet and sour,abundant blueberry fragrance,fermentation aroma,good antioxidant activity and in vitro bioavailability.