Optimization of Acetic Acid Fermentation Process of Apple Cider Vinegar

This paper studied the fermentation rules of apple cider vinegar from fruit juice,to provide a theoretical guidance for the production of apple cider vinegar.Using Fuji apples as raw materials,the process parameters(fermentation temperature,fermentation time,stirring speed,and inoculation amount)of apple cider vinegar fermentation were optimized through single-factor experiments and response surface analysis.The results indicated that the fermentation temperature had no significant effect on the total acid content of apple cider vinegar fermentation,the fermentation time had an extremely significant effect on the total acid content of apple cider vinegar fermentation,and the stirring speed and inoculation amount had a significant effect on the total acid content of apple cider vinegar fermentation.Through process optimization,the optimal process parameters for apple cider vinegar fermentation are fermentation temperature of 33℃,fermentation time of 39 h,stirring speed of 1500 r/min,and acetic acid bacteria inoculation amount of 7%.Under such conditions,the total acid content of fermented apple cider vinegar is 62.22 g/L,very close to the predicted value of the model,indicating that the process parameters of acetic acid fermentation obtained by response surface methodology(RSM)optimization are reliable and can be used for actual production prediction.

Application of Metabonomics in the Research of Lactic Acid Bacteria-fermented Foods

Lactic acid bacteria have been important industrial floras in the food fermentation production industry since ancient times.Their metabonomics technology has been widely used in the process monitoring,product classification and flavor formation mechanism of lactic acid bacteria-fermented foods.In this study,we discussed the application status of metabonomics technology in lactic acid bacteria-fermented food industry and scientific research,including dairy products,soy products,beverages and some pickled foods.Metabolomics will be applied in the research fields of lactic acid bacteria metabolism mechanism of lactic acid bacteria-fermented foods,lactic acid bacteria metabolomics database construction and expansion,metabolomics and genomics,and proteomics.In particular,the metabolomics technology will be introduced into product development and quality monitoring of traditional Chinese lactic acid bacteria-fermented foods,such as fermented bean curd and suancai,thereby perfecting industry norms and improving the level of industry development.

Screening and Properties of Functional Probiotics for Apple Fermentation

[Objectives]To screen functional probiotics for apple fermentation and study their probiotic properties.[Methods]A total of 35 strains were screened from traditional fermented foods in different regions.After primary screening,re-screening and research on growth characteristics,two characteristic strains,CTCF-LC1(LC1,with strong acid production ability)and CTCF-LT1(LT1,with strong adaptability),were obtained.[Results]The results of physiological and biochemical identification and 16S DNA-based identification show that LC1 is Lactobacillus casei and LT1 is Lactobacillus reuteri.Their fermentation performance in apple juice was tested,and it was found that the two strains grew well in the fermentation broth,and the total number of colonies could reach 10^(9) cfu/mL.The final pH value of LC1 fermentation broth dropped below 3.5,and the total acid content exceeded 12 g/L.The pH of LT1 fermentation broth dropped to 3.9,and the total acid content also exceeded 6 g/L.In the study on the antioxidation property of apple juice,it was found that after high temperature and high pressure steam sterilization,the DPPH free radical scavenging rate of apple juice extract increased by 35.8%,and potassium ferricyanide reduction capability increased by 68%.After fermentation by LC1 and LT1,the potassium ferricyanide reducing power of apple juice was increased by 42.9%.[Conclusions]This has a good application prospect in the development of fruit and vegetable juice fermented beverages.