The Research Of Rose Beverage By Lactic Acid Bacteria

The aim of this study was to evaluate the use of Rose as substrate for producing a probiotic beverage by Lactobacillus plantarum.We could get the probiotic beverage which strong rose fragrance and possessed much anthocyanins.The experiment mainly studied the extraction process,fermentation process,the blending of probiotic beverage and the storage period of cold storage.The main experimental results are as follows:1.Firstly,the optimization of the extraction process of rose extract was first optimized.The rose was broken and the rose liquid was extracted with pectinase and cellulase.The effect of extraction temperature,time and compound enzyme ratio on the extraction of rose liquid was studied with the anthocyanin content of extraction liquid as the index.Based on the single factor experiment results,the response surface methodology was applied to optimize the extraction process.The optimization results were as follows: the extraction temperature was 52?,the extraction time was 144 min,and the pectinase and cellulase ratio was 1:0.8.2.Then the parameters of the rose fermentation process was optimized.The response surface optimization method was used to optimize the initial pH and fermentation temperature.I determined the fermentation temperature range of this experiment was 10?~44?,pH 4.5~7.5,optimization basis for the number of live bacteria,anthocyanin content and sensory evaluation scores.The best results were achieved by fermentation at an initial pH of 4.7,reaching maximal cell density of 9.04Lg(CFU/mL)and total anthocyanin content54.2mg/L after 36 h at 30?.3.The rose probiotic beverage was allocated and the storage period was explored.The content of sugar acid ratio and stabilizer was tested after the fermentation of rose probiotic beverage.By adding sucrose gradient,the beverage could get the highest sensory score when the amount of addition was 3%.Different stabilizers were selected to explore the effect of different stabilizers on the stability of beverage.On the basis of single factor experiment,the response surface methodology was used to optimize the centrifuge sedimentation rate.The optimized results were carrageenan 0.03%,xanthan gum 0.04% andCMC-Na 0.03%.The rose beverage was placed in the refrigerator at 4 degrees centigrade,and the number of living bacteria,anthocyanin content,pH,acidity and sensory scores at different time were measured.On the 30 days of refrigeration,pH decreased from 4.15 to3.9,the number of viable bacteria decreased from 9.18 Lg(CFU/mL)to 7.98 Lg(CFU/m L),the anthocyanin content decreased from 52.9mg/L to 44.2mg/L,the acidity increased from0.52% to 0.728%,and the sensory score decreased from 83 to 69.They were all within acceptable range,so the beverage could be stored for 30 days.