低乙醛啤酒酵母风味优势菌株的选育

Screening of low-acetaldehyde beer yeast with flavor advantages

啤酒发酵过程中的乙醛主要由啤酒酵母代谢产生,其含量极大地影响啤酒的风味和品质。目前已有大量研究通过选育啤酒酵母来降低啤酒中乙醛含量,但由于大部分采用了分子手段或不符合食品安全条件的方式,尚未真正投入到啤酒的实际生产应用中去。本研究中,以啤酒企业提供的啤酒酵母YJ为出发菌株,经过常压室温等离子体诱变(Atmospheric and room temperature plasma,ARTP)处理,双硫仑平板初筛,摇瓶发酵复筛,获得了遗传稳定性和发酵稳定性良好的低产乙醛诱变菌株S48,进而在啤酒工厂进行100 L小试的发酵验证。结果发现,与出发菌株相比,诱变菌发酵的啤酒样品中乙醛含量降低了23.69%,其酒精度有所提高,苦味质、总酸和双乙酰含量更低,主要风味物质无较大差异,醇酯比及感官分析结果更加协调。

Acetaldehyde is mainly produced by yeast during beer fermentation,and its modification greatly affects beer flavor and quality.There are a lot of researches about the relationship between low-level acetaldehyde beer and yeast,however,due to the food safety,none of them have been applied to industrial beer production yet.In this study,we mutated the parent strain saccharomyces pastorianus YJ provided by beer company via ARTP(Atmospheric and room temperature plasma)and used a resistant plate combining disulfiram and ethanol to do the first round screening.Later,we selected the mutant strain S48 by several times of different flask fermentation.Compare with the parent strain,mutant strain(S48)lowered the amount of acetaldehyde by 23.69%,while alcohol was stronger,amaroid,total acid and diacetyl were lower in the factory fermentation tests.The flavor of fermentation liquor was better,and the alcohol with ester was more regulated.