Characterization of the aroma-active compounds in different infant formula using gas chromatography-mass spectrometry and odor activity value

In order to characterize the potential odor-active compounds in different infant formula, the study was carried out by aroma sensory evaluation, Gas Chromatography-Olfactometry-Mass Spectrometry combined with Aroma extract dilution analysis (AEDA), Gas Chromatography-Mass Spectrometry and Odor Activity Value (OAV). Multivariate analysis classified the 20 infant formula brands into five clusters, with hexanal, 1-octen-3-one, and (Z)-2-heptenal identified as the potential odor-active compounds distinguishing the brands. AEDA further revealed that aroma-active compounds such as 1-octen-3-one, (E,E)-2,4-nonadienal, and (E,E)-2,4-decadienal had flavor dilution (FD) factors of up to 256, demonstrating their important contribution to the aroma. Quantitative analysis revealed that a total of 38 volatile compounds were detected. The aldehydes contained 20 kinds, which were the most abundant substances among all the volatile compounds. Among 20 aldehydes, the content of 3-furaldehyde, hexanal, and heptanal was significantly higher than other components. Based on OAV calculation, 27 compounds were preliminarily screened as potential odor-active candidates, such as 1-octen-3-one, 1-penten-3-one, and 1-octen-3-ol. The 1-octen-3-one had the highest OAV among the 20 different brands. It is worth noting that there was an enormous gap between different brands of infant formula in terms of saturated aldehyde content. These findings will provide insights for subsequent in-depth research on the flavor of infant formula.