Process Optimization and Composition Analysis of Fermented Pomegranate Juice

The concentrated pomegranate juice as raw material, recovered and then the Lactobacillus acidophilus, Lactobacillus plantarum, and Saccharomyces cerevisiae were used as starters to make fermented pomegranate juice. And the fuzzy mathematics combined with response surface method was used to optimize the fermentation conditions of pomegranate juice. The sensory score values obtained by fuzzy comprehensive evaluation were selected as response variables to study the effect of sugar liquid, inoculated amount of Lactobacillus, fermentation time and fermentation temperature on the sensory quality of fermented pomegranate juice, and the headspace solid-phase microextraction (HS-SPME) coupled to gaschromatography-mass spectrometry (GC-MS) was used for the analysis of volatile compounds in fermented pomegranate juice. The results showed that the optimum fermentation condition of pomegranate juice was: adding sugar liquid (12% (w/w)), adding Lactobacillusplantarum (1.5%(w/w)), Lactobacillus acidophilus (1.5%(w/w)) and Saccharomyces cerevisiae (0.02% (w/w)) simultaneously, fermentation temperature (28 ℃), fermentation time (48 h). 38 volatile flavor compounds were detected in fermented pomegranate juice, mainly including alcohols and esters. The relative content of alcohols was 35.75%, and the relative content of esters was 42.59%.