In this study, solid phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GCMS) was used to investigate the volatile compound profiles of eight dairy fat products (including four butters, two creams and two cultured butters) that are popular on the Chinese market. Their key flavor compounds were identified by calculating relative odor activity value (ROAV) as well as using gas chromatography-olfactometry (GC-O). In total 40 volatiles were found in the eight milk fat products, including 7 aldehydes, 6 methyl ketones, 7 fatty acids, and 7 lactones. A total of 17 volatile compounds were identified as key flavor compounds according to their ROAV, and GC-O identified seven of these compounds. Acetic acid, butanoic acid, hexanoic acid, δ-octanolactone, δ-decanolactone and γ-dodecalactone, all of which had ROAV greater than 1 and could be recognized by GC-O, were considered the most significant flavor compounds in dairy fat products.

In this study, the effects of the denaturation degree of whey protein (WP) and whey protein/casein (WP/CN, m/m) ratio in milk powder on the emulsion stability and whipping properties of recombined cream were investigated. The results showed that the cream prepared from milk power with 60% of WP denaturation had good emulsion stability, and the stability of the system decreased with increase in denaturation degree. An increase in the degree of WP denaturation shortened the whipping time and reduced the leakage rate of whey. The emulsion stability at a WP/CN ratio of 1:4 first increased and then decreased to a level higher than the initial one with increasing proportion of WP. In addition, the whipping time of the cream was shortened, and whey leakage was reduced, while foaming rate declined and bubble collapse rate increased. In summary, the cream prepared from milk power with 60% of WP denaturation showed good emulsion stability and whipping properties; it had the best stability at a WP/CN ratio of 2:4 and better foaming capacity and foam stability at a WP/CN ratio of 1:4. Therefore, WP/CN ratio can be adjusted according to the practical needs to improve the functional characteristics of cream products.