小麦粉碎度与成品高温大曲理化和风味组分的相关性研究

Correlation between wheat pulverization degree and physicochemical and flavor components of high-temperature Daqu

该研究将粉碎度为不通过20目筛占比为55%、60%、65%的小麦分别用于高温大曲大试生产发酵,并对发酵过程进行监测,对理化结果进行了相关性分析、主成分分析和聚类分析;运用顶空固相微萃取结合气相色谱质谱联用技术解析了大曲挥发性风味物质演变规律;利用偏最小二乘回归法对理化特性及风味组分进行了关联分析。结果表明,小麦粉碎度为55%所制高温大曲的保水性最好;粉碎度为65%利于大曲升温生酸及麦皮中阿魏酸释放,利于生成愈创木酚。发酵结束时,3种大曲中吡嗪类、酚类和酮类物质含量占比由大到小依次对应的粉碎度分别为65%、60%和55%,醛类占比则在粉碎度为55%时最高。高温大曲中的优势风味物质主要包含异戊酸、苯乙醇、异戊醇、糠醛、3-糠醛、2,4-二叔丁基苯酚、愈创木酚、四甲基吡嗪、三甲基吡嗪、二甲基三硫等。感官结果表明,使用粗粉碎度小麦有利于提升高温大曲的烘烤香和酱香。该研究为优化高温大曲制曲工艺提供了坚实的理论与实践支持。

Wheat,as a raw material for starter-making,its crushing degree is particularly important to the quality of high-temperature Daqu.Based on the preliminary small-scale experiments,in this study,wheat with a crushing degree of 55%,60%and 65%,which did not pass the 20-mesh sieve,were used for the fermentation of high temperature Daqu,and the fermentative process was monitored.The physicochemical results were analyzed by correlation analysis,principal component analysis,and cluster analysis.The evolution of volatile flavor compounds in Daqu was analyzed by headspace solid phase microextraction combined with gas chromatography and mass spectrometry.The correlation analysis of physicochemical and flavor substances was carried out by partial least squares regression method.Results showed that the high-temperature Daqu produced with 55%wheat crushing degree had the best water retention.The crushing degree of 65%was conducive to the acid production,the release of ferulic acid in wheat bark,and the formation of guaiacol.At the end of fermentation,the proportions of pyrazines,phenols,and ketones in three kinds of Daqu,in descending order,corresponded to the wheat crushing degree of 65%,60%and 55%,respectively.The highest proportion of aldehydes occurred when the crushing degree was 55%.The advantageous flavor substances mainly included isovaleric acid,phenyl ethanol,isoamyl alcohol,furfural,3-furfural,2,4-di-tert-butylphenol,guaiacol,tetramethylpyrazine,trimethylpyrazine,dimethyl trisulfide,etc.The sensory results indicated that using coarse crushed wheat was beneficial for improving the baking and sauce flavor of high-temperature Daqu.The study provided solid theoretical and practical support for optimizing the starter-making techniques of high-temperature Daqu.