Amino acid promotes the formation of enals and 1-octen-3-ol from linoleic acid during the thermal reaction between alanine-xylose Amadori compound and Agrocybe aegerita enzymatic hydrolysates

Alanine (Ala)-xylose (Xyl) Amadori compound (A-X-ARP) was found to increase the yields of 1-octen-3-ol and enals derived from linoleic acid oxidation, during the thermal processing of Agrocybe aegerita enzymatic hydrolysates (AEH). To elucidate the key intermediate contributing to this enhancement, model systems combining linoleic acid with A-X-ARP, Ala, and glyoxal (GO) were established, and the reaction products were analyzed. Ala, regenerated through the decomposition A-X-ARP, was identified as a crucial factor driving the production of enals and 1-octen-3-ol. Further thermal reaction models of linoleic acid with amino acids featuring diverse side chains revealed the universal catalytic effect of amino acids on enals and 1-octen-3-ol formation. Moreover, the amino group within amino acids was determined to be the key functional group responsible for this catalytic activity. Notably, the presence of amino acid was observed to reduce the oxygen dependence of linoleic acid oxidation in producing 1-octen-3-ol and enals. As a result, the addition of A-X-ARP during the thermal treatment of AEH increased the yield of 1-octen-3-ol, a compound with a typical mushroom-like note, from 19.3 ± 3.7 (OAV = 19) to 71.4 ± 9.8 μg/L (OAV = 71). These findings provided new insights for the development of mushroom-flavored seasonings.