Abstract: The flavor and flavor stability of fresh and stored liquid Cheddar and Mozzarella wheys were compared. Pasteurized, fat separated, and unseparated Cheddar and Mozzarella wheys were manufactured in triplicate and evaluated immediately or stored for 72 h at 3 °C. Flavor profiles were documented by descriptive sensory analysis, and volatile components were extracted and characterized by solvent extraction followed by gas chromatography-mass spectrometry and gas chromatography-olfactometry with aroma extract dilution analysis. Cheddar and Mozzarella wheys were distinct by sensory and volatile analysis (P < 0.05). Fresh Cheddar whey had higher intensities of buttery and sweet aromatic flavors and higher cardboard flavor intensities following storage compared to Mozzarella whey. High aroma impact compounds (FDlog3 > 8) in fresh Cheddar whey included diacetyl, 1-octen-3-one, 2-phenethanol, butyric acid, and (E)-2-nonenal, while those in Mozzarella whey included diacetyl, octanal, (E)-2-nonenal, and 2-phenethanol. Fresh Cheddar whey had higher concentrations of diacetyl, 2/3-methyl butanal, (E)-2-nonenal, 2-phenethanol, and 1-octen-3-one compared to fresh Mozzarella whey. Lipid oxidation products increased in both whey types during storage but increases were more pronounced in Cheddar whey than Mozzarella whey. Increases in lipid oxidation products were also more pronounced in wheys without fat separation compared to those with fat separation. Results suggest that similar compounds in different concentrations comprise the flavor of these 2 whey sources and that steps should be taken to minimize lipid oxidation during fluid whey processing.
Practical Application: Cheddar and Mozzarella wheys are the primary sources of dried whey ingredients in the United States. An enhanced understanding of the flavor of these 2 raw product streams will enable manufacturers to identify methods to optimize quality.