Electronic nose and SPME-GAS cromatography for the study of the odor profile of whole milk power

the present study describes the strength of the electronic nose and headspace solid-phase microextraction-gas chromatography (hs-spme-gc) in food odor analysis. these methodologies were successfully applied to odor characterization of whole milk powder manufactured in a factory of the central dairy area of argentina. an electronic nose comprised of a set of 28 conducting polymeric sensors was used. different assays were conducted in order to define the protocol of analysis and examine the discriminative capability of the e-nose. for that purpose, a series of samples were evaluated while selected e-nose parameters undergone incremental changes in a pre-assigned routine, including sample equilibrium time, loop fill time, loop equilibrium time and inject time. hs-spme was used to isolate volatiles compounds such as dimethyl sulfide, pentanal, hexanal, and butyric acid, compounds that contribute significantly to describe the odor and flavor acceptance of whole milk powder. isolated compounds were characterized and quantified by gc with fid detection. extraction curves, limits of detection, repeatability, and linearity were investigated. limits of detection ranged between 0.6-400μgkg-1. applying the spearman correlation method, differences in the lineal relation between sensors and volatile compounds were observed according to the season of powder production. this study shows that the electronic nose technology can be applied to milk powder odor characterization, complementing analytical techniques like hs-spme-gc used in food odor research.