基于顶空气相-离子迁移谱技术对不同酵母发酵的百香果果啤香气比较

Aroma Comparison of Passion Beer Fermented by Different Yeasts Based on Headspace Phase-ion Mobility Spectroscopy Technology

酵母菌种对啤酒的风味与品质有着重大的影响。本文以皮尔森麦汁、啤酒花、啤酒酵母、百香果原浆和水等为主要原料酿造百香果果啤,采用气相-离子迁移谱(Gas chromatography-ion mobility spectrometry,GC-IMS)技术测定不同啤酒酵母(S-04、US-05、S-33、CS31和CN36)酿造的百香果果啤中挥发性香气化合物。采用主成分(Principal component analysis,PCA)与正交偏最小二乘判别分析(Orthogonal partial least-squares discrimination analysis, OPLS-DA),区分不同品种酵母酿造的百香果果啤。结果表明:采用GC-IMS共检测出37种挥发性香气成分,其中酯类16种、醇类8种、醛类6种、酮类4种、酸2种、烯烃类1种;PCA分析结果离散型较好,前两个主成分的累计贡献率为60.6%;OPLS-DA前两种成分总方差之和为68.1%,乙酸、辛酸乙酯、3-羟基-2-丁酮、己酸乙酯等17种风味化合物贡献率较大(VIP>1)。S-04发酵果啤特征性风味物质为乙酸和2-戊酮,US-05为丁酸甲酯,S-33为3-羟基-2-丁酮,CS31为辛酸乙酯、己酸乙酯、异戊醇和正丁醇,CN36为乙酸异丁酯、乙酸丙酯和丙酸乙酯。研究结果可为筛选适合生产百香果果啤专用酵母提供科学依据。

Yeast strains have a significant impact on the flavor and quality of beer. In this paper, passion beer was brewed with pearson wort, hops, yeast, passion juice and brewing water as raw materials. The volatile aroma components of passion beer brewed with different yeasts(S-04, US-05, S-33, CS31 and CN36) were analyzed by gas chromatography-ion mobility spectrometry(GC-IMS) technology. Principal component analysis(PCA) and orthogonal partial least-squares discrimination analysis(OPLS-DA) were used to distinguish passion beer brewed by different yeasts. The results showed that 37 volatile aroma compounds were detected by GC-IMS, including esters(16), alcohols(8), aldehydes(6), ketones(4),acids(2) and olefins(1). PCA showed the cumulative contribution rate of the PC1 and PC2 components was 60.6%. OPLSDA results showed 68.1% of the total difference, and 17 flavor compounds contributed significantly(VIP>1), including acetic acid, ethyl octanoate, acetion, ethyl hexanoate and so on. The characteristic flavor substances for S-04 fermented fruit beer was acetic acid and 2-pentanone, characteristic flavor substance for US-05 was methyl butyrate, characteristic flavor substance for S-33 was acetoin, characteristic flavor substances for CS31 were ethyl octanoate, ethyl hexanoate, 3-methyl-1-butanol and 1-butanol, and the characteristic flavor substances for CN36 were isobutyl acetate, propyl acetate and ethyl propanoate. The research results can provide a scientific basis for the selection of yeast suitable for the production of passion beer.