HS-SPME-GC-MS combined with multivariate statistical analysis reveals off-flavor composition and biomarker generation mechanism of whole milk powder

• Published in: Journal of food composition and analysis 2025-01, Vol.137, p.106962, Article 106962
• Main Authors: Ning, Miao, He, Kairu, Zhang, Dexi, Liu, Shengjia, Zhang, Yuxin, Min, Jie, Wu, Rina, Wu, Junrui, Zhang, Shuli
• Format: Article
• Language: English
• Subjects: Biomarker; biomarkers; discriminant analysis; dried milk; food composition; gas chromatography-mass spectrometry; grasses; headspace analysis; Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS); multivariate analysis; Multivariate statistical analysis; odors; off flavors; Off-flavor; principal component analysis; solid phase microextraction; whole milk; Whole milk powder
• ISSN: 0889-1575
• DOI: 10.1016/j.jfca.2024.106962

Milk powder is prone to producing off-flavor when it is not handled properly during production or storage. In order to identify the off-flavor compounds of whole milk powder (WMP), headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with cluster heatmap analysis was used, orthogonal partial least squares discriminant analysis (OPLS-DA) and principal component analysis (PCA) were used to investigate the off-flavor substances of whole milk powder. Cluster heatmap analysis showed that there were certain differences in the relative contents of volatiles among the eight milk powders. Further, OPLS-DA was applied to the relative contents of volatile substances in milk powders with and without unpleasant odor, a to obtain the main difference components of the 28 with variable importance in projection (VIP) greater than 1, with off-flavor substances being the main ones. Finally, the volatile compounds positively correlated with off-flavors in milk powder were screened by principal component analysis and combined with relative aroma activity values greater than 1 to identify (E)-2-hexenal and (E,E)-2,4-decadienal as the major off-flavor compounds of milk powder, and also described the mechanism of generation of (E)-2-hexenal (a marker of soya flavor) and (E,E)-2,4-decadienal (a marker of grass flavor) in milk powder. The results provide a reference for the analysis of flavor profile and possible off-flavor components of milk powder, which is beneficial for the optimization and improvement of whole milk powder. •The development of off-flavors such as oxidative, grassy and soya flavor in whole milk powder is related to volatile flavor substances•Headspace solid-phase microextraction gas chromatography-mass spectrometry coupled with model evaluation and multivariate statistical analysis for effective identification of off-flavors in whole milk powder•Low moisture content, high peroxide value and elevated stearic and oleic acid content explain the oxidative flavor of whole milk powder•(E,E)-2,4-decadienal and (E)-2-hexenal can be used as biomarkers for milk powder grassy and soya flavors