Study On Processing Technology Of Physalis-Jujube Juice Fermented By Lactic Acid Bacteria

This article mainly studies on the production process of fermented juices,with tested materials of Physalis and jujube,as well as finds the best fermentation condition for Physalis-jujube beverage.The experimental results are as follows:(1)The optimal fermentation strain and ratio study of Physalis-jujube beverage.The optimal strain and ratio are obtained through the change of lactic acid content,pH value and viable count of different lactic acid bacteria within 48 hours.The optimal fermentation strain are Lactobacillus acidophilus(Ld)and Lactobacillus plants(Lp).According to the compounding experiments with different proportions between the two kinds of lactic acid bacteria.The optimal fermentation ratio was La:Lp 2:1,and these had a cooperative fermentation capability.(2)The optimal fermentation conditions study of Physalis-jujube beverage.The optimal formula is obtained through single factor and response surface experiments.The best fermentation conditions are inoculation amount 10%,fermentation temperature 37℃ and fermentation time 20h.Sensory evaluation was used as the main indicator to adjust the flavor of fermented juice.Through single factor and orthogonal experiments,the best embedding process for fermented juice was adding 0.01%β-CD at 20℃ and stirring for 30 min.Aspartame,acesulfame K,fructose syrup,and citric acid were added in amounts of 0.04%,0.02%,8%and 0.03%.Through layering and sensory evaluation,the optimum amount of xanthan gumthe was 0.1%,and the fermented juice was smooth and no agglomeration.(3)Study on Active Components and Antioxidant Activity of Physalis-jujube beverage.This experiment measured the content of polyphenols,flavonoids and vitamin C in fermented juices,which were 0.1mg/mL,0.6mg/mL,0.15mg/mL.Five different methods were used to compare the antioxidant properties of the two juices.The results showed that anti-oxidation of fermented juice stronger than the puree·(4)Twenty one kinds of flavoring substances were newly generated in fermented juice.Among them,esters and phenols decline,and aldehydes,vinyls,acids and ketones increase.The compound beverage is stored at 4℃ and 26℃ respectively comparing its changes of pH,viscosity,centrifugation precipitating rate,soluble solids and hygienic indicator.The opital storage condition of compound beverage at 4℃.