Study On The Fermentation Technology Of Black Tea Beverage Fermented By Lactic Acid Bacteria

With its unique flavor and health care function,fermented tea drinks are favored by more and more consumers in daily life.In this study,the probiotics of lactic acid bacteria and the health care function of black tea were organically integrated to provide reference for the development of the production process of black tea beverage fermented by lactic acid bacteria.In this study,fujian special black tea product sachet black tea was used as the test material,the tea samples were obtained by crushing and extracting,and the composite lactobacillus was inoculated for fermentation,and the composite lactobacillus fermented black tea beverage was obtained by later mixing.The main research contents and results are as follows:1.The survival of Lactobacillus delbrueckii,Lactobacillus casei,Lactobacillus plantarum and Lactobacillus clavulgaris were studied at 37 ? for 48 hours in black tea extract samples with different amounts of black tea powder.The results showed that Lactobacillus casei did not detect viable flora in the black tea extract samples under the experimental conditions;Lactobacillus delbrueckii was soaked in 2.5%-7% black tea powder The results showed that the extract tea samples could grow and propagate,but could not survive in the 10% concentration of the extracted tea samples;Lactobacillus plantarum and Lactobacillus clavulgaris could grow and propagate in all kinds of black tea powder samples in this experiment,and 5% black tea powder was determined as the best tea powder addition proportion for producing fermented black tea powder;Lactobacillus casei was added into tea powder The results showed that 5% tea soup could not grow and propagate,and the p H value remained unchanged;Lactobacillus plantarum had the strongest acid production capacity,followed by Lactobacillus Corynebacterium,and finally Lactobacillus delbrueckii;the three Lactobacillus showed modern metabolism accumulation with time extension within 48 h fermentation time,and p H value decreased,and p H value tended to be stable after 48h;Lactobacillus plantarum and Lactobacillus Corynebacterium with similar fermentation performance were selected as production fermentation Compound strain of black tea beverage.In addition,0.5% proportion of lactic acid bacteria(Lactobacillus plantarum: Lactobacillus Corynebacterium = 1:1)was fermented in black tea with 5% tea powder under different temperature conditions.The p H value after 48 h fermentation was determined.The p H value decreased with the increase of temperature.The closer to the suitable temperature of 37 ? for lactic acid bacteria,the more organic acid accumulated,the more acid production capacity Considering the flavor of the finished product,30 ? was determined as the production temperature of lactic acid bacteria fermented black tea beverage.2.In this experiment,0.5% of compound lactic acid bacteria strains were fermented in 5% tea water at 30 ?,and the p H values of reaction samples were determined after different fermentation time.72 h was determined as the fermentation time of black tea beverage fermented by compound lactic acid bacteria.Taking the proportion of tea powder,fermentation temperature and fermentation time as independent variables,and sensory score of fermented black tea as response value,response surface analysis experiment of three factors and three levels was conducted to obtain the prediction equation of sensory quality of fermented black tea beverage.Through the optimization analysis,under the condition of 33 ?,the proportion of black tea powder was 5.6%,the reaction time after adding compound lactobacillus was 70 h.The sensory quality score of black tea beverage fermented by compound lactic acid bacteria(lactobacillus plantarum: Lactobacillus Corynebacterium = 1:1)was 93.67 points,which was close to the predicted value of 92.44 points.The volatile components and contents of black tea beverage fermented by compound lactic acid bacteria were detected by gas chromatography and mass spectrometry.The results showed that the aroma components of black tea extract tea samples after fermentation by compound lactic acid bacteria showed significant changes,among which the content of flowers and plants decreased,and the content of sweet aroma substances increased.3.through the late deployment experiment,the best sugar and acid ratio of the compound lactic acid bacteria fermented black tea beverage was 48:1,the dosage of green tea flavor was 5 g/L,0.02% sodium sorbic acid potassium +0.03% benzoate,D-sodium isoascorbate added 0.15g/kg,and sodium citrate 0.2%,which could improve the sensory quality of fermented black tea beverage while maintaining the effective fermentation of black tea beverage.Material stability.The results showed that the tea polyphenols and caffeine contents of the compound lactobacillus fermented tea beverage were 160.56 mg / kg and 29.85 mg / kg respectively,the transmittance was 92.65%,the p H was 3.92,the free amino acid content was 359.22 mg / L,and the total number of bacteria in the microbial health index was ? 5 No Escherichia coli and no pathogenic bacteria were detected,which met the requirements of the current national standard GB/T21733-2008 ?tea beverage?.