关键词: 玫瑰香干红葡萄酒, 本土酵母, 分离, 鉴定, 酿造特性, 混菌发酵

Abstract: Developing indigenous yeast strains is currently one of the most important trends in the production of featured Muscat wine. In this work, 337 yeasts were isolated by using PDA medium from spontaneously fermented Muscat wine, and then they were identified, counted and classified into seven groups by using Wallerstein laboratory (WL) solid medium. According to the results of yeast counting, the dominant strains were determined and then they were inoculated to bismuth sulphite glucose glycine yeast (BIGGY) agar to select yeast strains without H2S production ability, and the selected strains were molecularly identified for further characterization of enological traits. The physicochemical indexes and volatile compounds of Muscat wine fermented with these yeasts in mono-cultures or co-cultures were studied. Based on our experimental results, the potential of using these autochthonous yeast strains in Muscat wine production were discussed. Out of 337 yeast strains, three were selected for less or no H2S production, which were cataloged as HBKS-Y1, HBKS-Y2 and HBKS-Y3, and molecularly identified as Saccharomyces cerevisiae, Hanseniaspora uvarum and Saccharomyces cerevisiae, respectively. The alcohol, SO2 and sugar tolerance of the 3 yeast strains were high and met the requirements of wine vinification. When they were used to must fermentation either in mono- or co-culture, the physicochemical indexes including reducing sugar, alcohol, total acids, volatile acids, glycerol and acetaldehyde contents were within the range for dry red wine. In mono-culture fermentation, HBKS-Y2 was a strong producer of total and volatile acids. When HBKS-Y2 was co-cultured with HBKS-Y1 and HBKS-Y3, a synergistic effect was observed, which resulted in a decrease in total acids content and a significant decrease in volatile acids content compared with single culture of HBKS-Y2 while having no disadvantageous effects on the physicochemical indexes of wine. Furthermore, significantly higher contents of terpene alcohols, the characteristic aroma compounds of Muscat wine, were produced by fermentation with indigenous yeasts especially in co-cultures compared with dry active yeast. These results suggest that HBKS-Y1, HBKS-Y2, and HBKS-Y3 can be used as a fermentation starter for Muscat wine, and their co-culture has potential use in improving the variety-specific aroma of Muscat wine.

Key words: Muscat wine, indigenous yeast, screening, identification, enological characteristics, co-culture fermentation