Abstract: 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 GC-IMS 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%.

Key words: ham; KCl replacement; gas chromatography-ion mobility spectrometry; flavor; principal component analysis; partial least squares-discriminant analysis