结晶麦芽类黑精对拉格啤酒酵母KS-12发酵的影响

Effects of melanoidins extracted from crystalline malt on small-scale fermentation of lager yeast KS-12

类黑精是美拉德反应的重要产物,研究结晶麦芽不同分子质量类黑精对啤酒酵母生长、代谢和啤酒风味物质含量的作用,可以为啤酒风味的调控提供理论依据。类黑精可以促进酵母在对数期对麦汁中还原糖和α-氨基氮的利用,提高酵母细胞量;随着类黑精分子质量的增加,显著提高啤酒的色度和DPPH自由基清除率(P<0.05)。进一步通过气相色谱-质谱联用和高效液相色谱技术考察类黑精对啤酒风味物质产生的影响,结果表明添加高分子质量类黑精组(MW-H)啤酒中的高级醇含量与对照组相当,但乙酸乙酯、乙酸异戊酯、乙酸苯乙酯含量与对照组相比分别提高了14.62%,11.81%和14.70%;MW-H啤酒的乳酸含量为376.40μg/mL,显著高于对照组(97.83μg/mL)。结晶麦芽的类黑精通过提高啤酒醇类、酯类和有机酸物质的含量,改善啤酒的感官品质。

Melanoidins are important products of Maillard reaction.Clarifying the effect of melanoidins with different molecular weight on yeast growth,metabolism and beer flavor substance content can provide theoretical basis for the regulation of beer flavor.Melanoidins could promote the utilization of reduced sugar andα-amino nitrogen in wort by yeast in logarithmic phase,and increase yeast density.As the molecular weight of melanoidins increased,the colority and DPPH free radical scavenging rate of beer were improved significantly(P<0.05).Furthermore,the effect of melanoidins on beer flavor substances was studied by GC-MS and HPLC.The results showed that the advanced alcohol content in the high molecular weight(MW-H)beer was similar than that of the control,but ethyl acetate,isoamyl acetate,and phenyl acetate increased by 14.62%,11.81%and14.70%,respectively.The lactate content of the high molecular weight melanoidins(MW-H)beer was 376.40 g/mL,which was significantly higher than that in the control group(97.83 g/mL).The melanoi-dins from crystalline malt can improve the sensory quality of beer by increasing the content of alcohols,esters and organic acids.