The Research Of Wheat Germ Fermention Beverage Of Lactic Acid Bacteria

Wheat germ not only contains rich quality protein, unsaturated fatty acid, but also has antioxidant and other functions. In this study, we used different lactic acid bacteria to ferment the wheat germ beverage, analyse the nutrition and physical and chemical characteristics of the fermented wheat germ, and made a further study on the sterilization process of the beverage, etc.The results of ingredients determination showed that the contents of moisture, ash,total dietary fiber, protein,fat and carbohydrate in wheat germ were 8.05%±0.14%,5.97%%±0.61%, 11.66% ± 0.93%, 31.94% ± 0.71%, 9.85% ± 0.01%, and 32.49%±0.48%,respectively.Wheat germ was fermented by five kinds of lactic acid bacteria La, Lp,St,Lc and Lb in the fermentation process of wheat germ fermentation ,the changes of viable bacteria count, pH value, titration acid, reducing sugar content, free amino nitrogen content and soluble protein content in wheat germ fermentation broth were analyzed. The results showed that Lactobacillus plantarum, Lactobacillus casei and Lactobacillus producing acid ability is strong, but the ability of protein degradation Lactobacillus acidophilus is strongest.Streptococcus thermophilus is a kind of good aroma producing lactic acid bacteria. Five kinds of lactic acid bacteria were mixed with 1:1:1 , according to the content of organic acid produced by fermentation and protein degradation ability, choose the optimal combination for fermentation:La:Lp:St.The fermentation process and parameters of fermented beverage of wheat germ lactic acid bacteria was determined by single factor experiment and orthogonal experiment. The results showed that the optimum fermentation was as follows: the inoculation amount of lactic acid bacteria was 1%, the fermentation time was 8h, the ratio of material to water was 8:100(g/mL), under these conditions, the sensory evaluation value of fermented beverage was the best.By using single factor and orthogonal experiment, the stability of fermented beverage of wheat germ was studied with the centrifugal sedimentation rate as index:0.1% guar gum, 0.04% xanthan gum, 0.03% carboxymethyl cellulose, 0.1% carrageenan.The result of flavor substance analysis of wheat germ fermention beverage of lactic acid bacteria show that there were 62 kinds of volatile compounds in fermented wheat germ. Aldehydes,alcohols, esters and other aroma components and types of content increased.The result of the antioxidant activity of wheat germ fermention beverage of lactic acid bacteria show that the activity of scavenging DPPH radical and hydroxyl radical of wheat germ beverage after lactic acid bacteria fermentation was significantly increased,and the total phenol content was 112.22?g / mL.