Effect of substrates on the chemical compositions of oyster mushroom (Pleurotus ostreatus)

Abstract

The study investigated the effect of different substrates (log of dead wood (LDW); a mixture of rice husk and sawdust (RH+SD) on the chemical compositions of oyster mushroom (Pleurotus ostreatus). The mushroom samples were prepared in flour, and their proximate, mineral, vitamin, antioxidant, and antinutrient compositions were analysed using standard methods. The data obtained were analysed using an Independent T-Test at a 5 % level, revealing significantdifferences (p<0.05) in the values of proximate, mineral, vitamin, antioxidant, and antinutrient contents of the oyster mushroom. LDW-grown mushroom had higher protein (23.47 %) and fibre (15.51 %), while RH+SD-grown mushrooms had higher ash (8.01 %) and carbohydrate (56.36 %). LDW and RH+SD-grown mushrooms had higher magnesium (7.97 mg/100g) and calcium (4.97 mg/100g); zinc (7.97 mg/100 g) and iron (7.38 mg/100 g), respectively. Similarly, RH+SD and LDW-grown mushrooms had higher concentrations of vitamin A (4.23 mg/100g), vitamin D (216.82 mg/100 g) and vitamin E (4.08 mg/100 g), respectively. Antioxidant levels indicated that RH+SD-grown mushrooms had higher flavonoid (2.01 %) and total phenolic content (22.75 mg/100 g), while LDW had higher beta-carotene (13.39 mg/100 g). LDW-grown mushroom also had higher trypsin inhibitor (11.19 mg/100 g) and haemagglutinin (3.26 mg/100 g), while RD+SDgrown mushrooms had higher phytate (38.54 mg/100 g). These findings highlighted that substrates have significant effects on the chemical compositions of oyster mushroom, which offer promising nutritional and health benefits, supporting sustainable food production and dietary supplementation. Incorporating both LDW and RH+SD-grown oyster  mushrooms into diets to provide a range of nutritional benefits while also supporting sustainable food production practices is highly recommended.