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Effect Of Apple Variety And Yeast On Quality Characteristic Of Apple Wines

Posted on:2014-09-24Degree:MasterType:Thesis
Country:ChinaCandidate:G W LiFull Text:PDF
GTID:2251330401472663Subject:Food Science
Abstract/Summary:PDF Full Text Request
In this paper, apple wines were fermented from different apple varieties which wereproduced chiefly in shaanxi province (Jonagold, Fuji, Qinguan, Yuhua Early-Fuji,starkrimzon) and by different yeasts (WLP775、#4766cider、EXCE-SP、HARM-N°5).Influence of apple varieties and yeasts on physical and chemical characters, polyphenolprofiles and antioxidant activities of fermented liquors and fresh apple wines, aromacomponents of fresh apple wines were studied. The aim is to give theoretical foundation tostudy and produce high quality apple wines. The following are the main results:⑴Certain gap on physical and chemical characters between apple juice made from shaanxichiefly produced apple and ideal apple juice were existed, especially sugar of starkrimzon, pHand titrable acid of Qinguan.⑵Difference of fermented property of the four yeasts studied in this paper were found.Yeast1#(WLP775) has higher flocculation ability, but lower fermented ability and lowertolerance of alcohol and SO2. Yeast2#(#4766cider) and4#(HARM-N°5) have faster growthrates, higher fermented abilities, and higher tolerances of alcohol and SO2, but lowerflocculation. Yeast3#(EXCE-SP) has higher tolerance of alcohol and SO2, but lowerflocculation, and need longer time for adapting.⑶Apple variety has no obvious effect on total variation trend of physical and chemicalcharacters during fermentation of apple wine, but has effect on level of each index, time ofvariation emerged and amplitude of variation. Apple variety has obvious effect on physicaland chemical characters (except reducing sugar) of fresh apple wines. In addition, physicaland chemical characters of fresh apple wine has significant correlation with that of juice(P<0.05). Apple variety also have obvious effect on variation trend of polyphenols contents(catechin, ellagic acid, chlorogenic acid and caffeic acid) and antioxidant activities (exceptreducing capacity) during fermentation, and polyphenol profiles and antioxidant activities offresh apple wines. The analysis of aroma of fresh apple wines shows: the varieties andcontents of aroma of apple wines fermented from different apple varieties have obviousdiversity, but the relative content of ethanol, isopentyl alcohol, isoamyl acetate, ethylcaprylate and octanoic acid in these apple wines are all higher than1%. These aroma could beconsider as main aroma of apple wine. Apple wines studied in this research had been divided into two parts according to the content of alcohols and esters, and all apple wines fermentedfrom Fuji had been put into the same part which marked high alcohols content. Apple winesfermented from starkrimzon and Fuji had higher and stable sensory evaluation scores. Thus,we should pay more attention to starkrimzon and Fuji apple varieties in apple winefermentation.⑷Yeast has no obvious effect on total variation trend of physical and chemical characters,contents of polyphenols and antioxidant activities during fermentation of apple wine, but haseffect on time of variation emerged and amplitude of variation. Yeast has significant effect onphysical and chemical characters of fresh apple wines, but has no regularity. Yeast also has noobvious effect on polyphenol profiles and antioxidant activities of fresh apple wines. Thevarieties and contents of aroma of apple wines fermented by different yeast have obviousdiversity, it illustrates that yeast partly affect the aroma of fresh apple wines。Difference ofsensory evaluation had been found among apple wines fermented by different yeasts but noregularity been found.
Keywords/Search Tags:Apple wine, Apple variety, Yeast, Evaluation index
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