Study On Oats Fermented Beverage

The paper is aimed to fill the blank in the area of oats fermented beverage. One kind of oatsfermented beverage was made by the combination of enzymolysis and fermentation technology. Theeffect of strains and fermentation process on the beverage was studied. A unique process, includingenzymolysis and a two steps fermentation was explored in beverage manufacturing. At the sametime, the formula was optimized to improve the taste and stability of the beverage. Moreover, thebasic components and the change of volatile components during fermentation were illustrated toprovide theoretical basis in future research.Firstly, the method for preparation of oat syrup was established. The conditions of enzymatichydrolysis were optimized by taking reducing sugar content as the index. The optimum conditionsof middle temperature α-amylase were shown as following: enzyme12U/g, temperature60℃, pH6.0and hydrolysis time50min. The optimum conditions of glucoamylase were shown as following:enzyme100U/g, temperature65℃, pH4.5and hydrolysis time50min.Secondly, the effect of different fermentation orders of strains on beverage was studied. Theresults showed that the process of firstly fermented with Lactobacillus, and then Yeast was suitablefor oats fermentation. Fermentation characteristics of each Lactobacillus and Yeast were studied,Lactobacillus bulgaricus and Streptococcus thermophilus were chosen for the Lactobacillusfermentation, and Saccharomyces cerevisiae were chosen for the Yeast fermentation.Thirdly, the fermentation conditions of Lactobacillus and Saccharomyces cerevisiae wereoptimized by taking the sensory value as the index. The optimum conditions of Lactobacillus wereshown as following: inoculation3%, temperature41.9℃and time9.15h. The optimum conditionsof Saccharomyces cerevisiae were shown as following: inoculation0.13%, temperature33℃andtime1.5h. Under the conditions, the sensory value was80.5.Fourthly, the sugar-acid ratio was confirmed by taking the sensory value as the index. Theresults were shown as following: sugar10%and the sugar-acid ratio was50:1. The stability ofbeverage was optimized by using SR as the index. The results were shown as following: arabic gum0.077%, PGA0.027%and sodium alginate0.017%.Lastly, the nutritional components of the beverage were determined. The results were shown asfollowing: protein content0.43%, β-glucan content428.75mg/L, alcohol content0.278%(w/v),total amino acid2.94g/100g dry base, the ratio of essential amino to total amino acid26.84%, totalfree amino acid0.31g/100g dry base and the ratio of essential free amino acid to total free aminoacid30.42%. The volatile components of the beverage were also analyzed. The ratio of esters afterYeast fermentation was higher than Lactobacillus fermentation obviously.