Distinction of volatile flavor profiles in various skim milk products via HS-SPME–GC–MS and E-nose

Abstract

Volatile flavor profile of skim milk relates to product quality and consumer liking. The volatile compositions of different skim milk products are challenging to discriminate due to subtle constituents and inconspicuous peculiarities. This study develops a correlative analysis protocol for the characterization and differentiation of volatile flavor components in various skim milk products via headspace solid-phase micro-extraction gas chromatography–mass spectrometry (HS-SPME–GC–MS) and electronic nose (E-nose) with multivariate statistical analysis. Sixty-two volatile flavor components were identified in six skim milk products, which were paired into pasteurized skim milk, ultra-high-temperature skim milk, and modified skim milk, respectively. Distinguishable variation trends were observed upon the aroma response values of skim milk samples through the solid-state E-nose sensors. The results of principal component analysis, cluster heatmap analysis and Venn diagram analysis showed that significant distinctions in varying degrees among the six skim milk products could be presented in both volatile flavor composition and aroma release distribution. The correlative analysis by partial least squares regression indicated an adequate combination of HS-SPME–GC–MS and E-nose for the differentiation and classification of volatile flavor profiles in skim milk products. These findings provide an insightful perspective for the efficient flavor evaluation of fluid skim milk.