摘要
适应了产区风土条件的非酿酒酵母菌株,能够与酿酒酵母共接种发酵生成多元化的次级代谢产物,改变葡萄酒口感和香气特征。因此明确本土非酿酒酵母菌株的酿酒学特性差异,对定向调控葡萄酒风味品质具有重要应用价值。该研究以筛选自河西走廊葡萄产区的葡萄汁有孢汉逊酵母(Hanseniaspora uvarum)HX-1、HX-3,美极梅奇酵母(Metschnikowia pulcherrima)HX-2、HX-4和戴尔有孢圆酵母(Torulaspora delbrueckii)HX-6、HX-7为供试菌株,测定其生长曲线与酿酒因子耐受性后,分别接种于‘美乐’葡萄汁中进行纯种发酵,分析各菌株对酒样酿酒学参数及挥发性香气化合物的影响。试验结果表明,同一种属的菌株生长曲线相似,对高质量浓度葡萄糖和SO_(2)均有较好的耐受性;但在不同培养温度、pH值及乙醇体积分数条件下,菌株之间具有明显差异。HX-1、HX-3、HX-6和HX-7菌株表现出良好的低温耐受性,HX-1、HX-2、HX-3和HX-4菌株在低pH值条件下能正常生长,HX-6、HX-7菌株的乙醇耐受性最强。纯种发酵试验显示,HX-6、HX-7菌株在‘美乐’葡萄汁中发酵能力强、乙醇和甘油生成量较高。其中HX-7菌株与正庚醇、异戊醇、乙酸异戊酯等挥发性化合物的生成强相关,HX-6菌株能有效增加葡萄酒中癸酸乙酯、辛酸乙酯等酯类化合物的含量。2株H.uvarum均显著(P<0.05)增加了葡萄酒中总酸与苹果酸含量,并有助于葡萄酒中C_(13)-降异戊二烯的生成;但HX-1菌株的还原糖利用率较差,酒精发酵在第8天停滞。HX-4菌株相对高产挥发酸,HX-2菌株能够显著增加葡萄酒中香茅醇、柠檬烯等品种香气化合物的含量。综合分析,本土T.delbrueckii和H.uvarum菌株在纯种发酵过程中的酿酒学参数及香气特征具有种内相似性,而M.pulcherrima的发酵特性呈现菌株依赖性。研究结果可为精准设计葡萄酒混菌酒精发酵策略提供科学参考。
Non-Saccharomyces yeast(NS)strains can be adapted to generate diverse secondary metabolites,in order to alter the flavor and aroma characteristics of wines.Particularly,the NS strains are co-inoculated with Saccharomyces cerevisiae in the terroir of the production area.Therefore,it is of great significance to identify the differences in the oenological characteristics of autochthonous NS strains,in order to regulate the wine flavor.In this experiment,the test strains were selected as Hanseniaspora uvarum(HX-1,HX-3),Metschnikowia pulcherrima(HX-2,HX-4),and Torulaspora delbrueckii(HX-6,HX-7)isolated from spontaneously grape juice in Hexi Corridor wine region.A systematic measurement was performed on the growth curves of these 6 non-Saccharomyces yeast strains,together with their tolerance to vinification factors.The results showed that the NS strains belonging to the same genus showed similar growth curves,and all strains were well tolerant to the high concentrations of glucose and SO_(2),among which HX-2,HX-6,and HX-7 still grew normally at a glucose concentration of 300 g/L.Except for the HX-6 strain,the growth of the rest strains was only slightly inhibited at an SO_(2) concentration of 300 mg/L.Notably,there were significant differences among the tested strains under different culture temperatures,pH,and ethanol levels.Among them,HX-1,HX-3,HX-6,and HX-7 strains showed excellent low-temperature tolerance,where their OD600 values reached more than 0.6 under the fermentation temperature of 15℃.In addition,HX-1,HX-2,HX-3,and HX-4 strains grew normally under low pH conditions.HX-6 and HX-7 strains showed the strongest tolerance to ethanol.In particular,the growth of HX-6 was slightly inhibited,where the absorbance value reached 0.569 when the ethanol level reached 9%.All the test strains were inoculated into Merlot grape juice for pure fermentation,in order to investigate the vinification performance of these NS strains.The oenological parameters of the wine samples were determined to detect the volatile aroma compounds using HS-SPME-GC-MS.Pure culture fermentation experiments showed that the HX-6 and HX-7 strains exhibited strong fermentation ability and high production of ethanol and glycerol during Merlot wine making.Torulaspora delbrueckii strain HX-7 was closely related to the formation of volatile compounds,such as 1-heptanol,isoamyl alcohol,isoamyl acetate,isoamyl acetate,and ethyl acetate,while the HX-6 strain was effectively improved the content of ester compounds,such as ethyl caprate and ethyl caprylate in wine samples.Hanseniaspora uvarum strains HX-1 and HX-3 significantly enhanced the content of total acidity and malic acid,with great contribution to the formation of C_(13)-norisopentadiene in the wines.The limited reducing sugar by the HX-1 strain resulted in the alcohol fermentation stagnation on the 8th day after inoculation.The HX-4 strain shared a high yield of volatile acidity.The HX-2 strain significantly increased the content of varietal aroma compounds,such as citronellol and linalool in Merlot wine.Hierarchical clustering of the oenological parameters combined with the aroma compounds revealed that there were significant intraspecific or interspecific differences in the fermentation characteristics of the tested NS strains.Comprehensive analysis showed that the oenological parameters and aroma profile of the autochthonous Torulaspora delbrueckii and Hanseniaspora uvarum strains during pure culture fermentation showed intraspecies similarity,while the fermentation characteristics of Metschnikowia pulcherrima showed strain dependence.The finding can provide a scientific reference to regulate the flavor quality of wines using mixed fermentation.
作者
徐彬艳
张璇
石琳
王媛
祝霞
杨学山
XU Binyan;ZHANG Xuan;SHI Lin;WANG Yuan;ZHU Xia;YANG Xueshan(College of Food Science and Engineering,Gansu Agricultural University,Lanzhou 730070,China)
出处
《农业工程学报》
北大核心
2025年第2期318-327,共10页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(32260637,32060581)
甘肃省葡萄酒产业发展基金项目(20180820-08,20180820-07,GCJ-2019-125-1)
甘肃农业大学校列科研项目(GSAU-ZL-2018-8)。
关键词
非酿酒酵母
纯种发酵
挥发性化合物
层次聚类分析
偏最小二乘法判别分析
non-Saccharomyces yeasts
pure culture fermentation
volatile compounds
hierarchical cluster analysis
partial least squares discrimination analysis
