Effects of continuous enzymolysis on the umami characteristics of Lentinula edodes and the flavor formation mechanism of umami peptides.

The purpose of this study was to explore the effect of continuous enzymolysis on the umami characteristics of Lentinula edodes and illuminate the umami mechanism of peptides. The results indicated that the continuous enzymolysis extracts (LFTE) of L.edodes had higher umami intensity and palatability than the water extracts (LWE). 1H NMR and LC-MS/MS were used to evaluate taste metabolites and peptide profiles. Among the identified peptides, LPGVAE, LDELEK, DVELSK, LPDEAR, and TTLPDK with high umami scores which threshold in the range of 0.091-0.371 mmol/L were screened by iUmami-SCM and BIOPEP-UWM, and further verified by sensory evaluation. The results of molecular docking suggested that Ser148, Asn150, Ser276, Ser278 of T1R1 and Asn68, Val277, Ala302, Ser306 of T1R3 played a key role in the umami peptides docking. The study revealed continuous enzymolysis of L.edodes could obtain more umami substances and umami peptides, which laid a foundation for researching flavor substances and developing flavor products from L.edodes.

Quality characteristics and non-volatile taste formation mechanism of Lentinula edodes during hot air drying.

In this paper, the changes of non-volatile taste substances and the formation mechanism of taste quality of Lentinula edodes during hot air drying at 50 °C were studied. The results showed that with the increase of drying time, the moisture content gradually decreased, volume shrinkage, color deepening, chewiness and viscosity first increased and then decreased. After drying for 8 h, when the moisture content reached 28.68%, the appearance, taste and the overall quality of L.edodes were better. After 12 h drying, the content of free amino acids and organic acids increased significantly, while the content of 5'-nucleotide and soluble sugar decreased significantly, and the EUC value was higher. Succinic acid has the highest TAV value, which contributes the most to the taste of dried L.edodes products. Comprehensive quality analysis of drying process and the guidance for rehydration of dried L.edodes were also predicted.