Lipase-catalyzed alcoholysis of butter for acid value reduction: a comparative study with lipase-catalyzed hydrolysis

Lipase-catalyzed hydrolysis can improve butter flavor but may cause acid accumulation and undesirable taste. In this study, ethanol was employed as an acyl acceptor to establish an lipase-catalyzed alcoholysis system, and its effects on butter properties and volatile profiles were compared with lipase-catalyzed hydrolysis. After 72 h, lipase-catalyzed hydrolysis increased the acid value from 0.75 to 8.74 and 3.03 mg KOH·g −1 for Palatase 20,000 L and lipase MHA 10SD, whereas ethanol reduced it to 0.72 mg KOH·g −1 (91.8% reduction) and 0.85 mg KOH·g −1 (71.9% reduction). Volatile analysis showed that hydrolyzed butter was characterized by acids, ketones, and lactones, whereas alcoholyzed butter exhibited low acids and ester-dominated profile, with ethyl butyrate and ethyl octanoate as major esters. Lipase-catalyzed alcoholysis effectively reduced acid accumulation and shifted the flavor toward fruity and creamy profile, providing a promising strategy for producing high-quality flavored butter with improved sensory properties and industrial application potential.