Comparison of umami-taste active components in the pileus and stipe of pine-mushrooms (Tricholoma matsutake Sing.) of different grades

Umami-taste active components in pine-mushrooms (Tricholoma matsutake Sing.) were compared according to different grades (first, second, third, and fourth) and parts (pileus and stipe). The contents of umami-taste active free amino acids, such as aspartic acid and glutamic acid, decreased in the order of second grade > third grade > fourth grade > first grade. Also, the contents of umami-taste active 5′-nucleotides were highest and lowest in pine-mushrooms of second and first grades, respectively. All the contents of umami-taste active amino acids and 5′-nucleotides were higher in the pileus than in the stipe, irrespective of pine-mushroom grades. Equivalent umami concentration values of pine-mushrooms ranged from 13.26 (in the stipe of first grade) to 204.26 g (in the pileus of second grade) per 100 g. All the quantitative data obtained in this study are highly consistent with our previously data on umami sensory intensities of pine-mushrooms.