Nutritional Profile and Microbial Analysis of Pleurotus ostreatus Cultivated on Agricultural Residues

Pleurotus ostreatus is a widely cultivated edible mushroom, which offers significant nutritional and medicinal benefits. In this study, P. ostreatus was cultivated on various agricultural residues: sawdust, corncob, cassava peel, and plantain peel. The agricultural residues which served as substrates were further sun-dried, soaked in water, and packed into polyethylene bags; after which they were sterilized and inoculated with P. ostreatus spawn. The inoculated bags were then incubated at 25-30°C and 90% relative humidity for the period of 20 days. The nutritional profile, mineral content, and phytochemical composition of the substrates and cultivated mushrooms were analyzed. Furthermore, the microbial load of the substrates and mushrooms was assessed using standard microbiological methods. The obtained results revealed significant differences in nutrient content among substrates and mushrooms when compared statistically. Mushrooms exhibited higher protein (2.88 ± 0.02%), fiber (3.94 ± 0.01%), and mineral content compared to the agricultural residual substrates. The analysis revealed that mushrooms cultivated on plantain peel demonstrated the highest levels of flavonoids (4.18 ± 0.01 mg/kg) and alkaloids (4.07 ± 0.11 mg/kg). Also, Microbial analysis revealed a significant reduction in microbial load in the cultivated mushrooms compared to the substrates. These findings highlight the potential of P. ostreatus cultivated on agricultural residues as a sustainable and nutritious food source. The study further emphasizes the importance of selecting appropriate substrates to optimize mushroom quality and reduce potential microbial contamination. Hence, further research is needed to explore the impact of different cultivation techniques and environmental factors on the nutritional and medicinal properties of P. ostreatus.