高产乳酸耐热克鲁维酵母的筛选及其在葡萄酒中增酸潜力研究

Screening of high-yield lactic acid Lachancea thermotolerans and their potential to increase acid in wine

通过比较16株耐热克鲁维酵母(Lachancea thermotolerans)的产乳酸能力及耐受性,筛选高产乳酸的优良菌株,并将其与商业酿酒酵母(Saccharomyces cerevisiae)EC1118按1∶1配比共发酵制备霞多丽葡萄酒,评估其酿造特性。结果表明,耐热克鲁维酵母菌株LT-XJ24、LT-XJ59、LT-ZX03与LT-GS27的耐受性较好,且产乳酸能力较强,在葡萄汁中的乳酸产量分别为6.41 g/L、6.52 g/L、7.89 g/L和6.21 g/L。优选的4株耐热克鲁维酵母与商业酿酒酵母共发酵均能完成霞多丽葡萄酒的酒精发酵,且均具有良好的生物增酸能力,其中菌株LT-ZX03混合发酵的霞多丽葡萄酒中的乳酸产量最高,达6.66 g/L。尽管混合发酵组提高了葡萄酒的挥发酸含量,但仍然符合相关标准要求(≤1.2 g/L)。从霞多丽葡萄酒样品中共检出41种香气物质,包括23种酯类、11种醇类、5种酸类以及2种其他类化合物,其中13种物质的香气活度值(OAV)>1。不同耐热克鲁维酵母对霞多丽葡萄酒中挥发性香气物质的影响存在差异,其中菌株LT-GS27和LT-ZX03影响较大,能够提高葡萄酒中具有花果香气的丁酸乙酯、己酸乙酯、辛酸乙酯和癸酸乙酯等物质含量。

In this study,the superior strains with high-producing lactic acid were screened by comparing the lactic acid-producing ability and tolerance.16 strains of Lachancea thermotolerans co-fermented with Saccharomyces cerevisiae EC1118 according to ratio of 1∶1 to produce Chardonnay wine,as well as their brewing characteristics were evaluated.The results showed that L.thermotolerans LT-XJ24,LT-XJ59,LT-ZX03 and LT-GS27 had great tolerance and strong lactic acid production capacity,with lactic acid production of 6.41 g/L,6.52 g/L,7.89 g/L and 6.21 g/L,respectively.Co-fermentation of the 4 screened strains of L.thermotolerans with commercial S.cerevisiae could complete the alcoholic fermentation of Chardonnay wine,and all had good bioacidification ability,among which the lactic acid yield of Chardonnay wine by mixed fermentation with strain LT-ZX03 was the highest,reaching 6.66 g/L.Although the mixed fermentation group increased the volatile acid content of Chardonnay wine,it still met the relevant standard requirements(≤1.2 g/L).A total of 41 aroma compounds were detected from Chardonnay wine samples,including esters 23,alcohols 11,acids 5 and others 2.Among them,the odor activity value(OAV)of 13 compounds was greater than 1.The effects of different L.thermotolerans on volatile aroma substances in Chardonnay wine were different.Among them,the strains LT-GS27 and LT-ZX03 had the greatest effect,which could increase the contents of ethyl butyrate,ethyl hexanoate,ethyl caprylate,and ethyl caprate with floral and fruity in wine.