A model for the involvement of lignin degradation enzymes in phenolic antioxidant mobilization from whole soybean during solid-state bioprocessing by Lentinus edodes

Solid-state bioprocessing (SSB) of food substrates by dietary fungi is a promising and innovative strategy for the production of phenolic-enriched foods and food ingredients. Previously we reported the involvement of carbohydrate-cleaving enzymes (CCEs) and laccase in SSB of soybean by dietary fungi. Here, we investigated the involvement of lignin degradation activities in SSB of soybean by Lentinus edodes. Total peroxidase, manganese(II)-peroxidase (MnP), and β-glucuronidase activity were investigated in addition to total soluble phenolic content, antioxidant activity of the phenolic extracts, and the enzymic activities of laccase, amylase, α-glucosidase, and β-glucosidase. Phenolic mobilization from soybean during SSB was associated with MnP and laccase activity, in addition to amylase and β-glucosidase activity. Further, decreased antioxidant activity was associated with total peroxidase and laccase activity. A model for SSB of soybean by dietary fungi, such as L. edodes was hypothesized and discussed.