The availability of ethanol: A decisive factor in the biosynthesis of ethyl esters in enzyme-modified cheese flavor

• Published in: Food chemistry Vol. 483; p. 144245
• Main Authors: Fang, Sicong, Xia, Yixun, Chen, Maoshen, Zhong, Fang
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.08.2025
• Subjects: Alcoholysis; Biosynthesis; Cheese - analysis; Cheese - microbiology; cheeses; esterases; Esterases - chemistry; Esterases - metabolism; Esterification; Esters - analysis; Esters - chemistry; Esters - metabolism; ethanol; Ethanol - analysis; Ethanol - metabolism; Ethanol availability; ethyl acetate; Ethyl esters; Fermentation; flavor; Flavoring Agents - chemistry; Flavoring Agents - metabolism; food chemistry; Humans; lactic acid; Lactic acid bacteria fermentation; Lactobacillales - metabolism; Lactobacillus helveticus; octanoic acid; Odorants - analysis; odors; sensory evaluation; Taste; Volatile Organic Compounds - chemistry; Volatile Organic Compounds - metabolism; wines; Alcoholysis; Biosynthesis; Esterification; Ethanol availability; Ethyl esters; Lactic acid bacteria fermentation
• ISSN: 0308-8146; 1873-7072; 1873-7072
• DOI: 10.1016/j.foodchem.2025.144245

Lactic acid bacteria (LABs) exhibit a strong acid-producing capability in the manufacturing of enzyme-modified cheese flavor (EMCF), but their limited ester synthesis ability resulted in EMCF having strong sour aroma with imbalance flavor. Strains with higher esterase activity were screened by simulated fermentation. Lacticaseibacillus casei exhibited greater activity in synthesizing ethyl hexanoate and ethyl octanoate, while Lactobacillus helveticus had a higher yield of ethyl acetate. The analysis of volatile compounds revealed that ethyl esters were not detected under the conditions of both fatty acids and esterases, indicating that ethanol served as a key substrate limiting the synthesis of esters. The addition of ethanol significantly increased both the variety and concentration of volatile compounds, especially acids, alcohols, and ethyl esters. Sensory analysis indicated that ethanol contributed to the development of fruity and wine aromas. EMCF exhibitd a softer flavor at 0.5 % ethanol addition, which providing practical insights for balancing EMCF flavor. [Display omitted] •The low ethanol content was the main reason for the absence of ethyl esters in EMCF.•The addition of ethanol effectively promoted ethyl ester synthesis in EMCF.•Ethyl esters contribute to the flavor balance of EMCF and reduce sourness intensity.