Serving temperature effects on milk flavor, milk aftertaste, and volatile compound quantification in nonfat and whole milk

Many people seem to prefer to drink cold milk. Research describing the flavor and aftertaste of milk and their correlation with chemical composition has not been reported previously. The study objectives were to describe milk flavor and aftertaste with a descriptive sensory panel and to quantify the headspace compounds of nonfat and whole milks as a function of serving temperature, and then to determine if correlations exist between the data sets. Headspace compounds of milk samples served at 4 degrees C and 15 degrees C were quantified by using solid-phase microextraction (SPME) gas chromatography, flame ion detection (GC-FID). Descriptive panel results indicated that serving temperature did not affect milk flavor. Nonfat milk was rated as having more sour aromatics, bitter, cooked, and fat character and as being slightly more chalky and flat, but less sweet than whole milk. Characterization of milk aftertaste at 15 s after swallowing indicated that nonfat milk had very slight sour and cooked attributes. Characterization of milk aftertaste at 90 s after swallowing indicated that nonfat milk had very slight cooked attributes and was less sweet than whole milk. Nonfat milk had a greater concentration of hexanal and lesser concentrations of benzaldehyde, ethyl caproate, heptanal, 2-heptanone, and nonanal than whole milk did. Significant correlations were found between fat derived compounds and fat influenced descriptors. These data provide evidence that fat content/composition contributes to the "flavor" and aftertaste attributes of milk more than serving temperature does.