基于气相色谱-离子迁移谱结合多元统计学分析KCl部分替代NaCl对宣威火腿挥发性风味化合物的影响

Influence of Partial Replacement of NaCl with KCl on the Volatile Compounds of Xuanwei Ham Investigated by Gas Chromatography-Ion Mobility Spectrometry Combined with Multivariate Statistical Analysis

为降低宣威火腿中的钠盐含量,采用KCl部分替代NaCl,并分析成品火腿挥发性风味的变化。以100%NaCl为对照,使用KCl分别替代30%、40%、50%和60%NaCl的低钠宣威火腿为研究对象,基于气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)技术对不同KCl替代的宣威火腿挥发性化合物进行分析。结果表明,GC-IMS可以实现对宣威火腿风味化合物差异的快速分析,共检测出49种挥发性化合物,以醛类、酮类、醇类和酯类为主;通过主成分分析和偏最小二乘-判别分析(partial least squares-discriminant analysis,PLSDA)等多元统计学方法,直观地对不同KCl替代组宣威火腿进行有效区分。此外,基于PLS-DA,共筛选出24种化合物被鉴定为特征标志物(VIP>1),其中丙酸乙酯、2-戊酮(单体)、乙酸乙酯(二聚体)和乙缩醛等,是影响不同KCl替代组宣威火腿风味差异的重要成分。通过热图聚类分析,对照组与30%KCl替代组宣威火腿在风味上较为相似。因此,为了保持传统宣威火腿的风味,KCl替代量不应超过30%。

In order to reduce the content of sodium salt in Xuanwei ham,the effect of partial replacement of NaCl with KCl on the volatile compounds of Xuanwei ham was studied.In this study,100%NaCl was used as the control,and 30%,40%,50%and 60%KCl were used to replace NaCl and considered as treatment groups.By gas chromatography-ion mobility spectrometry(GC-IMS),the volatile compounds of Xuanwei ham were analyzed.The results showed that GCIMS could quickly identify differences in volatile flavor compounds among ham samples.A total of 49 volatile compounds were detected from all samples,mainly including aldehydes,ketones,alcohols and esters.Multivariate statistical analysis including principal component analysis(PCA)and partial least squares-discriminant analysis(PLS-DA)could clearly distinguish Xuanwei ham samples with different levels of KCl substitution.In addition,based on PLS-DA analysis,a total of 24 compounds were selected and identified as characteristic markers(VIP>1),including ethyl propanoate,2-pentanone(monomer),ethyl acetate(dimer)and acetal,which were the important components contributing to the difference in flavor among Xuanwei hams with different levels of KCl substitution.According to the results of heat map clustering analysis,the control group and the 30%KCl substitution group were similar in flavor.Therefore,in order to maintain the flavor of traditional Xuanwei ham,the KCl substitution level should not exceed 30%.