The intensity of blue light-emitting diodes influences the antioxidant properties and sugar content of oyster mushrooms (Lentinus sajor-caju)

- B-LED of mushrooms significantly promoted the accumulation of dry biomass.
- Different light intensities variably affected the antioxidant system of the mushroom, and higher light intensities resulted in an increased DPPH radical-scavenging effect, Fe-chelating ability, and reducing power.
- 40 PPFD of the B-light source caused greater accumulation of soluble sugars than other B-light intensities.

In this study, we examined the influences of four light intensities on mushroom biomass and effects of a blue (B) light-emitting diode (LED) source with 10-40 μmol m−2 s−1 of photosynthetic photon flux density (PPFD) on the antioxidant capacity and soluble sugar content of the edible oyster mushroom L. sajor-caju Fr. which is popularly cultivated in Taiwan. Fruiting body initiation and development of mushrooms cultivated on blocks made of sawdust, rice-bran, and wheat-bran media were carried out with an 8-h photoperiod at 26 °C and 85% relative humidity under LEDs lights inside growth chambers. When the basidiome has began development, mushroom blocks containing primordia were exposed to different light conditions for 7 days. Results showed that B-LED PPFD of mushrooms significantly promoted the accumulation of dry biomass. This study explored the relationship between the light intensity of B-LED and antioxidant properties. Different light intensities variably affected the antioxidant system of the mushroom, and higher light intensities resulted in an increased DPPH radical-scavenging effect, Fe-chelating ability, and reducing power. In addition, 40 PPFD of the B-light source caused greater accumulation of soluble sugars than other B-light intensities. Precise management of B light may hold promise in promoting the nutritional value of edible mushrooms cultivated in controlled environments with future utilization of LEDs on an industrial scale.