【作者】 郭志刚；

【导师】 赵长增； 刘天明；

【作者基本信息】 甘肃农业大学 ， 果树学， 2008， 硕士

【摘要】 本文以分离自甘肃的146株野生酵母为材料,通过杜氏管发酵法初筛出24株发酵力强、香味浓的酵母作为供试菌株。抗性(耐SO2、耐高渗、耐高温、耐酸碱、耐高浓度葡萄糖及耐酒精)评价结果表明:其中23株酵母耐SO2浓度达650 mg/L ;17株耐NaCl浓度高达280.0 g/L;8株耐50℃高温;9株耐pH在1.5～12.5之间;23株耐650.0 g/L的葡萄糖;6株耐18%(Vol)的乙醇。模拟发酵结果表明:菌株QCH7、HYHT6、HYHP3C、HYHT1C、GS38A起始发酵快,其中菌株GS38A产酒度为8%(Vol),GS13F产浓郁果香。以筛选的3株天然葡萄酒酵母菌株GS13F、GS38A、HYHP3C和商品葡萄酒酵母RC212进行单菌株发酵和组合发酵生产甘肃原产地干红葡萄酒,葡萄原料赤霞珠和蛇龙珠采自武威黄羊镇。酒样理化指标及香气成分的GC-MS分析结果表明,以天然酵母菌株发酵的酒样,理化指标均符合葡萄酒国标要求,菌株GS38A发酵酒的酒度(7.2%)与RC212 (8.0%)接近,而菌株GS13F的发酵香种类多、比例协调,主要有乙酸异戊酯(27.54%)、乙酸苯乙酯(15.67%)和2-苯乙醇(9.85%)。菌株配伍发酵后GS13F产香特性与GS38A、RC212高酒度特性优势互补,且发酵香种类和含量均增加,酒体骨架更为丰厚协调,可用于甘肃产地葡萄酒的生产。此外,以采自甘肃武威和山东烟台的赤霞珠葡萄为原料,用酵母菌株GS13F和GS38A发酵酿造干红葡萄酒,分别对葡萄汁和酒样进行香气成分的GC-MS分析。结果表明,两产区葡萄的香气成分均检出8种,但其种类和含量有显著差异。采自武威的主要是邻苯二甲酸二甲酯(68.48%)和邻苯二甲酸二乙酯(10.05%);而采自烟台的主要是邻苯二甲酸二甲酯(46.62%)和2-苯乙醇(7.69%)。葡萄酒样中香气成分的种类和含量很大程度上由葡萄本身所含的香味物质决定。在酿造过程中使用不同的酵母菌株对葡萄酒香气成分的种类和含量的贡献值明显不同。这表明不同生态因子和不同酵母菌种(株)对地域特色葡萄酒的风格形成有重要影响。对8株优良菌株依据形态学特征和26S rDNA Dl/D2序列分析进行鉴定,共鉴定出4属4个种(或变种),其中优势属为Candida和Kodamaea。更多还原

【Abstract】 146 yeast strains were separated from Gansu province in China and used in the experiment. 24 strains with high fermentation capacity and thick flavour were screened out by Durham tube method. The results of resistance evaluation of some strains(tolerant to high concentration of SO2, NaCl, high temperature and acidity , as well as glucose and alcohol) showed that 23 strains could grow in high concentration of SO2 over 650 mg/L, 17 strains grow in high concentration of NaCl over 280g/L , 8 strains grow at 50℃, 9 strains grow at pH1.5～12.5, 23 strains grow in 650 g/L glucose medium and 6 strains could grow in 18%(vol)alcohol medium. The results of the formulation fermentation showed that strains QCH7、HYHT6、HYHP3C、HYHT1C、were short for fermenting primary period, that GS38A alcoholicity was 8%(Vol), and SQ4 is thick aroma.Three natural yeast strains(GS13F,GS38A,HYHP3C)were used in single or combination for original dry red wine fermentation with two grape cultivar Cabernet sauvignon and Cabemet gemischt harvested from Wuwei , commercial yeast RC212 as the control. The results of the chemical index and aroma-component analysis with GC-MS showed that the chemical index of the wine with natural strains could satisfy the demand of China wine standard, that the alcoholicity of the wine with strain GS38A(7.2%)was close to that of RC212(8.0%), that most aroma components were from fermentative process, that GS13F produced more suitable and more kinds of aroma components,the main aroma components were n-Amyl acetate(27.54%)、2-Phenylethyl acetate(15.67%)and 2-Phenylethanol(9.85%).In combining with GS38A and RC212, the characteristic of producing aroma components of GS13F was complemented with the high alcoholicity of GS38A or RC212,and the aroma type and content increased, the wines tasted more rich and harmonious, suggesting their potentiality in producing original wine. Meanwhile, Two Cabernet sauvignon grapeberry material(harvested from WuWei and YanTai ) were used for dry red wine fermentation with two natural wine yeast strains(GS13F and GS38A). aroma-component analysis for the grape bunch and wine respectively, The results showed that 8 aroma-components were found in each grapes for each area, but the type and content were significant different. The main aroma components of the grape harvested from WuWei were Dimethyl phthalate(68.48%)and Diethyl phthalate(10.05%),while the main aroma components of the grape harvested from YanTai were Dimethyl phthalate (46.62%)and 2-Phenylethanol(7.69%). The type and content of aroma components of wine were largely decided by aroma components of grape. In the course of brewing, different yeast strains have apparently different contribution to the aroma components type and content of the wine.8 yeast strains were identified based on the combination of morphology and 26S rDNA Dl/D2 domain sequence analysis, the 4 species of them (or variety)belonging to 4 genera. The dominant genera identified were Candida and Kodamaea .更多还原