Flavour‐active compounds in thermally treated yeast extracts

BACKGROUND: Aroma-active compounds and non-volatile substances determine the characteristic aroma and taste of yeast extract (YE). Changes in the characteristic aroma and taste of YE due to thermal reaction are rarely studied, and the relationship between aroma-active compounds and non-volatile compounds is not yet clear. RESULTS: Non-volatile compounds identified by HPLC and LC/MS/MS were reduced by a rise in temperature, except for some amino acids. Peptides underwent degradation. In addition, a further rise in temperature above 120 °C resulted in a bitter and sour taste. Furans, pyrazines, thiophenes, thiazoles and some branched chain sulfur compounds were derived from GC/O/MS (SPME and SAFE). Sensory results revealed that the concentration of volatile compounds increased with an increase in temperature. The overall aroma profiles of YE at 25, 100 and 110 °C were buttery, green, nutty and meaty, while YE at 140 °C had a strong sour and sulfur odour. CONCLUSION: The non-volatile compounds of YE were reduced and different volatile compounds were produced under different thermal treatments. There was a negative correlation between these two types of compounds. The different taste sensors and all precursors were correlated with each other. There are significant relationships between different odorants and aroma-active compounds of YE after thermal treatment. © 2018 Society of Chemical Industry.