Studies Of Treatments Of Apple Juice And Yeasts On Cider Brewing

The key that develops apple industry steadily, healthily and continuously is to enhance the benefit of the apple processing industry. Advancing the processing technology and new apple product quality is an important way to raise the benefit of the apple industry. The apple-fermented products have upstanding market vista. The base to develop this market is to apply advanced techniques. As the core of this research, the treatments of apple must have important influence on cider brewing. By the advanced statistics analysis, brewing and analysis techniques, the influences of fresh pressing apple juice treaments, the cider yeast and raw material on cider brewing were researched. Primarily study results as follows:1. The clarifying of apple juices was effected significently by adding CaCl2. More brilliantly clear juices were obtained in less clarifying time compared with the control. The higher acidity and lower pH value of fermented apple juice was reached with the CaCl2 treatment. There were no significant differences on alcohol fermentation. The Clarified apple cider with CaCl2 treatment had higher titration acidity, lower residual sugar, total extract, and good taste with fresh fruit aroma. The optimal dosage of CaCl2 was 0.4g/L when the must treatment time was less than 12h, however the 0.3g/L was enough as the time up to 18-22h.2. The Vc treatment increased the acidity and decreased the pH value and color strength of the cider. In the prophase fermentation, the propagation and fermentation of ther yeast was restrained by adding Vc to 1.00g/L. The good taste and typical fruit aroma cider was obtained with 0.75g/L Vc added.3. In the prophase fermentation, the propagation and fermentation of wild yeast was restrained by adding SO2. The clarified juice was easily reached. The lower color strength juices that compared with the control were obtained,however the color strength of apple juicees were decreaseing with the increasing of SO2. By 0.75g/L SO2 added, the cider had good taste and obvious fruit aroma.4. By the analysis of RSM equation and the experiments, when apple must was treatment with CaCl2, Vc, and SO2, A(SO2)＝0.76, B(Vc)＝－0.19, C(CaCl2)＝0.57 were the optimum selection.5. Among the four yeasts used in this reasch, Yeast 3# was fittest to brew cider in this experiment. The cider with good taste, the typical fruit aroma and typical style was obtained.6. In contrast with apple juice concentrate, fermentation of fresh apple juice resulted in higher and more stable fermenting speed. The cider was endowed with higher alcohol degree, the lower residual sugar and fine color. During fermentation, the titration acid was increased by 0.8-1.0g/L; however, more combined sulfur dioxide was obtained in the cider brewed by fresh apple juice.