Abstract: The changes of taste compounds in Lentinula edodes during vacuum freeze-drying (VFD) were explored using an electronic tongue (E-tongue), high performance liquid chromatography (HPLC) and an automatic amino acid analyzer. Sampling took place after pre-freezing, primary drying, and secondary drying (20, 30, 40 or 50 ℃). E-tongue results showed that L. edodes samples collected at different VFD stages were effectively distinguished. The contents of soluble sugars/mannitols and 5’-nucleotides significantly increased after pre-freezing (P < 0.05). After primary drying, the contents of soluble sugars/mannitol and free amino acids (FAAs) in L. edodes reached maximum values of 185.20 and 44.76 mg/g, respectively among all sampling points. After secondary drying, the content of organic acids increased independent of the drying temperature, while the contents of soluble sugars/mannitols and FAAs showed different decreasing trends with the drying temperature. The umami intensity of L. edodes greatly increased after secondary drying at 30, 40 or 50 ℃, leading to an approximately 2-fold increase in equivalent umami concentration (EUC) values as compared to the fresh sample. In conclusion, most of the taste compounds in L. edodes were well retained during the VFD process. These results should provide insights into understanding the mechanism of change in taste compounds in L. edodes during vacuum freeze-drying and provide an important reference for the development of seasonings based on the taste of L. edodes.

Key words: Lentinula edodes; vacuum freeze-drying; taste compounds; equivalent umami concentration; dynamic change