The Effect of Fermented Buckwheat on Producing L-carnitine Enriched Oyster Mushroom

Abstract

L-carnitine is biological compound which serves intake of long chain fatty acids into mitochondria to metabolize. L-carnitine is considered as a nutritious supplement for weight-loss. It is synthesized in human organ, but most of L-carnitine which human intakes is originated from meat based foods. In this study, for the first time we produced L-carnitine enriched mushroom using fermented buckwheat prepared by Rhizopus oligosporus fermentation. Oyster mushroom (Pleurotus ostreatus) was used to cultivate L-carnitine enriched mushroom. The mushroom grown on buckwheat medium contained 9.9% to 23.9% higher L-carnitine concentration than basal medium without any buckwheat addition. Fermented common buckwheat added medium grown mushroom contained the highest L-carnitine content of 201.2 mg·kg-1. The size index and the lightness of mushroom pileus (L*) were the highest, respectively 100.7 and 50.6, with fermented common buckwheat (20%, w/w) added medium. The antioxidant activities of mushroom extracts (1.5 mg/ml) against DPPH radicals were 38.7 % at mushroom grown with the common buckwheat and fermented common buckwheat added medium. The cytotoxicity test against Raw 264.7 cell of mushroom ethanol extracts resulted that fermented buckwheat mushrooms showed EC50 307.2 µg·mL-1, but on normal media showed 255.1 µg·mL-1.