Metabolic profiles, bioactive compounds, and antioxidant capacity in lentinula edodes cultivated on log versus sawdust substrates

Abstract

Lentinula edodes (shiitake) is a popular nutritious edible mushroom with a desirable aroma and flavor. Traditional cultivation of L. edodes on beds of logs has been replaced by cultivation on sawdust, but the effects of cultivation changes on L. edodes mushrooms have not been well charac-terized. We determined the metabolic profile, bioactive compounds, and antioxidant capacity in L. edodes grown on log or sawdust substrates. Metabolic profiles of L. edodes extracts were determined by1H nuclear magnetic resonance (NMR) and ultra-performance liquid chromatography to quad-rupole time-of-flight mass spectrometry. Principal component analysis score plots from1H NMR analysis showed clear differences between samples. Concentrations of primary metabolites, espe-cially amino acids, generally decreased in L. edodes grown on logs compared to sawdust. Phenolic compounds showed variations in concentration depending on the cultivation method. Bioactive compounds and their antioxidant capacity were analyzed spectrophotometrically. L. edodes cultivated on logs had high concentrations of bioactive compounds with strong antioxidant capacity compared to L. edodes cultivated on sawdust. Thus, the concentration of primary metabolites was high in L. edodes grown on sawdust, which produces a high growth rate. In contrast, log-cultivated L. edodes, which were similar to wild mushrooms, had high levels of bioactive compounds and high antioxidant capacity. This information is useful for determining optimal cultivation conditions for nutritional and medicinal uses of L. edodes mushrooms.