| 摘要: |
| 【目的】对不同发酵方式发酵苹果酒的理化性质和挥发性成分以及感官风味进行研究，为苹果酒的生产和香气调控提供参考。【方法】采用酿酒酵母（Saccharomyces cerevisiae）WLS21和异常威克汉姆酵母（Wickerhamomyces anomalus）YN6发酵苹果酒，设置WLS21、YN6纯发酵及WLS21和YN6顺序发酵、同时发酵4种发酵方式,发酵9 d，发酵过程中每天取样称重法测定酒液CO2产量，手持折射仪测定酒液糖度，pH计检测酒液pH，平板计数法统计酒液中的酵母生物量，通过气相-离子迁移谱（GC-IMS）分析4种苹果酒发酵过程中挥发性成分的变化，采用气相色谱（GC）对最终苹果酒的酒精度进行检测，并对4种苹果酒进行感官评价。【结果】WLS21纯发酵的发酵趋势与WLS21和YN6同时发酵相似，产CO2及降糖速率均较快，糖度均由起始的13.50%降至4.60%左右，最终苹果酒酒精度分别达到6.06%和5.67%；YN6纯发酵与WLS21和YN6顺序发酵的发酵速率均较慢，发酵结束时糖度分别为8.80%和5.27%，最终苹果酒酒精度为3.47%和5.37%。发酵液的pH在发酵过程中总体呈上升趋势，起始pH为3.56，发酵结束时4种苹果酒的最低pH为3.60。在顺序发酵过程中，WLS21的生长受到抑制；而在同时发酵过程中，WLS21占据主导。GC-IMS共识别到58种挥发性化合物，发酵过程中1-丁醇和1-己醇相对含量减少，乙酸乙酯、乙酸异戊酯等酯类物质随着发酵进行相对含量增加，YN6参与的发酵可以产生较丰富的酯类化合物。感官评价显示，新鲜水果香、花卉香味、香草香、烘焙香是苹果酒的主要风味，以顺序接种发酵苹果酒的总得分最高。【结论】不同发酵方式影响苹果酒的理化性质和感官性质，非酿酒酵母耗糖低，发酵产生低醇苹果酒，顺序接种发酵有利于苹果酒产生更丰富的酯类物质，进而对苹果酒的感官风味产生积极影响。 |
| 关键词: 苹果酒 发酵方式 酿酒酵母 异常威克汉姆酵母 气相-离子迁移谱 风味分析 |
| DOI： |
| 分类号: |
| 基金项目:国家“十三五”重点研发计划项目（2019YFC1606703）；陕西省农业科技创新转化项目（NYKJ-2019-XA-008） |
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| Effects of fermentation methods on physicochemical properties and volatile components of cider |
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LIU Yongping,YUE Tianli
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| Abstract: |
| 【Objective】The physicochemical properties,volatile components and sensory flavor of cider fermented by different fermentation methods were studied to provide reference for cider production and aroma control.【Method】Saccharomyces cerevisiae WLS21 and Wickerhamomyces anomalus YN6 were used to ferment apple cider using four fermentation treatments of WLS21 and YN6 pure fermentation,sequential fermentation and simultaneous fermentation for 9 days.Daily samples were collected during fermentation to determine CO2 production.The sugar content was measured by a handheld refractometer.The pH change of the fermentation liquid was monitored by a pH meter,and the change of yeast biomass was counted by the plate counting.Gas chromatography-ion mobility spectrometry (GC-IMS) was used to analyze the changes of volatile components in the fermentation process.Gas chromatography (GC) was used to detect the alcohol content of the final cider,and sensory evaluation was conducted.【Result】The WLS21 pure fermentation and simultaneous fermentation had similar fermentation trends.The CO2 production and sugar reduction rate of WLS21 and simultaneous fermentation were fast.The sugar content decreased from the initial value of 13.50% to about 4.60% with final cider alcohol contents of 6.06% and 5.67%,respectively.YN6 pure fermentation and sequential fermentation were slow.At the end of fermentation,the sugar contents were 8.80% and 5.27%,and the final cider alcohol contents were 3.47% and 5.37%,respectively.The pH of fermentation broth generally showed an upward trend during the fermentation process.With initial pH of 3.56,the lowest pH of the four ciders was 3.60 at the end of fermentation.During sequential fermentation,the growth of WLS21 was inhibited,while it dominated during simultaneous fermentation.A total of 58 volatile compounds were identified by GC-IMS.During fermentation, relative contents of 1-butanol and 1-hexanol decreased,while that of ethyl acetate,isoamyl acetate and other esters increased.YN6 participation produced more abundant ester compounds.The sensory evaluation showed that fresh fruit aroma,flower aroma,herbal aroma and baking aroma were the main flavor aromas of cider,and sequential fermentation had the highest score.【Conclusion】Different fermentation methods affected the physicochemical properties and sensory properties of cider.Non-Saccharomyces yeast consumed less sugar and produced low-alcohol cider.Sequential inoculation was beneficial to cider to produce more abundant esters,which in turn had positive effects on the sensory flavor. |
| Key words: cider fermentation method Saccharomyces cerevisiae Wickerhamomyces anomalus gas chromatography-ion mobility spectrometry flavor analysis |
