Comparative Effects of Different Proteases on the Non-Volatile Taste Compounds and Volatile Flavor Fingerprints of Sarcodon imbricatus Hydrolysates

Enzymatic hydrolysis with proteases efficiently releases taste active and volatile compounds from mushroom matrices; however, how protease specificity impacts the flavor characteristics of Sarcodon imbricatus (S. imbricatus) remains unclear. In this study, S. imbricatus was treated with Flavourzyme, Protamex, and Bromelain to produce hydrolysates, and the resulting changes in non-volatile taste-active compounds and volatile flavor characteristics were systematically evaluated by free amino acid analysis, 5′-nucleotides determination, electronic tongue, and HS-GC-IMS. The results show that enzymatic hydrolysis significantly affects its flavor characteristics. Flavourzyme treatment resulted in the highest degree of hydrolysis (29.24 ± 0.65%) and free amino acid (47.46 ± 1.02 mg/g) accumulation, whereas Protamex produced the highest equivalent umami concentration (EUC) value (115.81 g MSG/100 g), indicating stronger umami synergism between amino acids and 5′-nucleotides. Bromelain also altered the flavor characteristics after hydrolysis, but to a lesser extent. Electronic tongue analysis further showed that enzymatic hydrolysis generally enhanced umami and reduced bitterness, with Flavourzyme exhibiting the most pronounced effect. Meanwhile, HS-GC-IMS identified 69 volatile compounds and showed that FSIH and PSIH had more pronounced effects on the volatile profiles of S. imbricatus. Furthermore, 16 discriminatory markers (VIP > 1) were screened, indicating distinct volatile modulation by different proteases. Overall, Flavourzyme exhibited the most balanced performance and was considered the preferable protease for S. imbricatus hydrolysis under the present conditions. These findings provide a theoretical basis for its further processing and natural seasoning development.