Study On The Optimizing Technology And Control Of Formation Of Higher Alcohol During Cider Fermentation

In order to produce high quality cider and solve the existing problems of ciderindustrialized production in our country, this paper firstly screened the yeast for ciderproduction by doing yeast growth characteristics and cider fermentation tests, and thenstudied the best fermentation conditions of the high quality yeast strain, aiming atproviding theoretical support for the industrial production of high quality cider;Higheralcohol is indispensable to the wine flavor substances, but much more content of higheralcohol will bring adverse effects to the liquor. Based on the fermentation conditionsoptimizing experiments, this paper also studied the generating control of higher acoholin cider brewing process. Tests’ specific research contents and the results were asfollows:1. We screened cider yeast firstly by comparing the the advantages anddisadvantages of each strain on growth characteristics and quality of fermenting wine.Tests shew that three strains’ growth properties had not significantly differences andeach of them belonged to wine yeast; Characteristics of the three strains’ brewing baseliquor were as follows: golden yellow, fine and smooth bouquet, harmonious bouquetand fruit,"light" mellow taste,having typical style of cider, but Y2’s liquor was turbidand had relatively lowwer wine degrees, Y3’s liquor had relatively higher acidity.Comprehensively considerating, Y1strain was selected as the experimental strain.2. Having chosen Y1as the fermentation strain, the influences of five factors-theinoculation quantity, fermentation temperature, sugar content, initial pH value andadditive content of (NH4)2HPO4on the cider quality was studied by single factorexperiment and orthogonal test. The best conditions determined by tests were asfollows: inoculation amount10%, sugar content19g/100mL, initial pH value3.5,(NH4)2HPO4200mg/L and fermentation temperature20℃.3. To reduce the adverse effects of high alcohol on the liquor, this paper havestudied the generating control of cider high alcohols. A single factor experiment shewthat: among the wine brewing allowing factors’ level range, the inoculation quantity, theinitial pH value and additive quantity of (NH4)2HPO4were the main influence factors.Box-Behnken test shew that: the effect of the inoculation quantity on the generation ofhigher alcohols was extremely significant (P <0.01), the effect of the additive contentof (NH4)2HPO4and juice’s initial pH value on the generation of higher alcohols were significant (P <0.05); The best combination of fermenting conditions determined bytests was as follows: sugar content16g/100mL, fermentation temperature18℃,inoculation quantity9.3%, additive quantity of (NH4)2HPO4155mg/L and initial pHvalue3.3.