基于挥发性风味物质分析的小麦储藏年份鉴别方法研究

Identification method of wheat storage year based on volatile flavor compounds analysis

目的基于挥发性风味物质分析鉴别小麦储藏年份。方法采用固相微萃取-气相色谱-质谱法对小麦籽粒样品进行检测,采用主成分分析、凝聚层次聚类并结合偏最小二乘法判别分析对不同储藏年份的小麦样品的挥发性风味物质种类和含量进行分析,建立基于挥发性风味物质分析的小麦储藏年份鉴别模型。结果对收获期为2018年至2022年共5个年份的小麦样品进行检测,检出挥发性风味物质73种,包括醇类、醛类、酮类、杂环化合物、酸类、酯类、醚类、烃类和酚类物质。基于变量投影重要性筛选出37种对主成分分类贡献较大的差异化合物,其中γ-辛内酯、γ-庚内酯、γ-己内酯、γ-壬内酯、1-庚醇、1-己醇和1-戊醇含量与小麦储藏年份呈正相关,被确定为特征差异化合物。结论不同储藏年份小麦中挥发性风味物质含量存在差异,基于特征差异化合物构建的分类模型有望用于小麦储藏年份的快速、准确鉴别,为小麦的品质鉴别提供一定的技术支撑。

Objective To identify storage year of wheat based on volatile flavor compounds analysis.Methods Wheat grain samples were detected by solid phase microextraction-gas chromatography-mass spectrometry.Principal component analysis,agglomerative hierarchical clustering and partial least squares discriminant analysis were used to analyze the types and content of volatile flavor components in wheat samples of different storage years to establish a wheat storage year identification model based on volatile flavor compounds analysis.Results Wheat samples harvested in 5 years from 2018 to 2022 were detected.A total of 73 volatile flavor compounds were detected,including alcohols,aldehydes,ketones,heterocyclic compounds,acids,esters,ethers,hydrocarbons,and phenols.Based on the variable importance in projection as the threshold,37 kinds of differential compounds with great contributions to the classification were screened out.Among them,the content ofγ-octalactone,γ-heptalactone,γ-caprolactone,γ-nonolactone,1-heptanol,1-hexanol,and 1-pentanol were identified as the characteristic differential compounds,which were positively correlated with the storage year.Conclusion There exists a difference in the content of volatile flavor components in wheat with different storage years.The classification model based on characteristic differential compounds is expected to be used for rapid and accurate identification of wheat storage year,which provides certain technical support for the quality identification of wheat.