优良酵母菌株发酵特性研究

优良酵母菌株发酵特性研究

STUDY ON THE EXCELLENT YEAST FERMENTATION CHARACTERISTICS

作者：王　可　　导师：刘天明

山东轻工业学院　　发酵工程2011届硕士

摘　要

酵母菌是葡萄酒酿造的主要微生物，不同的酵母可以赋予葡萄酒不同的感官风味。近来人们开始重视众多天然酵母在原产地葡萄酒生产中的重要贡献，积极开发与商品酵母耦合发酵的原生态天然菌群，实现多菌株组合发酵，充分凸现天然酵母的优良特性，酿造味感丰富、香气浓郁、风格独具的产地葡萄酒。本研究以烟台蛇龙珠和赤霞珠葡萄为原料，用筛选的2株天然葡萄酒酵母菌株ZYFJQ、YQY和商品酵母RC212、D254组合发酵生产干红葡萄酒，从中筛选最佳组合，并重点评价优良天然菌株与商品酵母组合发酵对葡萄酒理化指标、感官质量及香气构成的影响。

酒样感官品评结果显示，多菌株共发酵酒样香气丰富 。 蛇龙珠葡萄尤以D254+ZYFJQ菌株组合发酵获得的酒样最佳，香气纯正，有愉悦的果香和醇香，品种典型性强，发酵酒在理化指标和香气协调性上较为突出。GC-MS 分析表明，陈酿后多数发酵香气种类仍然保留，新生香气主要为高级醇酯，这些香气与果香协调性较好。RC212+D254+YQY 三菌株共发酵产生 38 种香气成分，香气成分最多，醇香浓郁，口感柔和。而赤霞珠葡萄以 RC212+ZYFJQ 菌株组合发酵获得的酒样最佳，香气馥郁，入口果味突出，优雅纯正。香气分析显示，陈酿香种类在发酵香气的基础上明显增加。新生高级醇种类多，且复杂，有利于产地酒风格的形成。RC212+D254+YQY 三菌株共发酵产生 31 种香气成分，酒样口感和谐。RC212+ZYFJQ组合发酵的酒样在理化指标和香气协调性上较为突出，是烟台生产产地赤霞珠葡萄酒的理想组合。

比较酵母不同接种方式（不同时间、比例和顺序）对蛇龙珠葡萄酒品质影响研究发现，先接入天然酵母 ZYFJQ 的组合发酵都产生了较为丰富、柔和的香气，以 15#（先接 ZYFJQ 菌株 48h 再加等体积 D254菌株）为最佳，酒样共检出发酵香成分 35 种，其中 1,6-二氢香芹烯醇和橙花叔醇以往未见报道。天然菌株 ZYFJQ单独发酵时间越长，所产香气物质越多，而 ZYFJQ 接入量对葡萄酒香气的影响不明显。

关键词　天然酵母　共发酵　产地葡萄酒　烟台

Abstract

Yeast is the main microorganisms during wine-making. Different yeasts can give different types of wine flavors. Winemakers are recently focusing on the important contribution of natural yeast to make the　original wine,or in combination with commercial yeast. The wines that co-fermented by natural yeast with commercial yeasts together have rich taste and aroma,unique features as well. In this paper,two natural yeast strains ZYFJQ and YQY,separated from grape berry,were used to produce dry red wine by using single strain or in combination with commercial yeasts RC212 and D254,with the raw grape harvested from Yantai grapery. The mainly purpose of this study is to select the best combination and to evaluate the influence of selected yeast strains on the physic-chemical indexes,the sensory quality and aroma component of the wine.

Sensory evaluation showed that the co-fermented wine was rich in aroma flavors. D254+ZYFJQ is the best combination for wine with Gernischt grape,the wine has purely pleasant fruity and alcohol aroma,and cultivar’s typical flavor expresses very strong. Aroma components by GC-MS analysis showed that fermentation aromas were substantially retained,a number of super-alcohol ester was examined after ageing,and super-alcohol ester could balance better with varietal aroma. The combination of RC212+D254 +YQY produced 38 components of aromas,with thicker alcoholic bouquet and more harmonious taste.

RC212+ZYFJQ is a better combination for grape Cabernet Sauvignon,the wine has fruity taste and aroma complexity,finess and purity. Aroma analysis showed that a large number of complicated super-alcohols,except for fermentation aroma,were detected after ageing. This is good for the　formation of original wine typicality. The combination of RC212+D254 +YQY produced 31 components of aromas in wine,with more harmonious taste. D254+ ZYFJQ is a better combination for making Yantai original wine,its balance between physic-chemical indexes and aroma is more prominent.

The experiment was conducted to examine the natural yeasts impact on Gernischt wine quality by different inoculation methods (different time,seed ratio of strain,and order). The results showed that the combinations which first inoculated strain ZYFJQ produced more rich and smooth mouthfeel. 15# is the best one,which firstly inoculated ZYFJQ and then added an　equal volume of D254 after 48h. 31 aroma components were determined from the wine sample of 15#,1,6-dihydrocarveol and nerolidol were detected for the first report. The longer time ZYFJQ fermented alone,the more aromas it produced,but inoculation ratio of ZYFJQ has no obvious influence on wine aroma.

Key words　Natural yeast　Co-fermentation　Original wine　Yantai