Umami-enhancing effect of Agaricus bisporus-pork bone stocks based on the EUC value and sensory evaluation

In this study, Agaricus bisporus and pork bone stocks (PBS) were enzymatically digested, and the equivalent umami concentration (EUC) value, sensory evaluation and hydrolysis degree (DH) were used as indexes to find the optimal enzyme digestion conditions. Finally, the optimal enzymatic solution was mixed and analyzed for flavor compounds in the optimal enzymatic solution before and after Maillard reaction (MR) by GC × GC-O-MS. The results showed that the enzymatic digestion of mushroom stocks (MS) with a combination of Cellulase-Protamex™ (C-P) yielded high levels of flavor amino acids (40.733 ± 0.340 g/L), and 5′-nucleotides (12.807 ± 0.239 mg/g), and EUC values up to 1755.786 ± 40.759 g/100 g. Meanwhile, the simultaneous enzymatic hydrolysis of PBS with a combination of Flavourzyme™-Protamex™ (F-P) yielded high levels of flavor amino acids (51.265 ± 0.550 g/L) and 5′-nucleotides (17.477 ± 0.260 mg/g) with EUC values up to 3420.619 ± 114.193 g/100 g. Using the DH and sensory evaluation as indicators, the results showed that the greatest DH and the highest sensory scores were obtained with the addition of C-P-MS and F-P-MS at 7:3 (m/m). Finally, the compounds with large changes in concentration were mainly mushroom flavored 1-octen-3-ol (2208.614 ± 12.879 μg/kg), sweet-flavored 3-octanone (269.871 ± 11.691 μg/kg), floral-flavored benzyl alcohol (156.704 ± 14.859 μg/kg), green flavored 2-pentylfuran (190.470 ± 12.934 μg/kg), and almond-flavored furfural (523.555 ± 5.674 μg/kg).