The Impact of Substrate Composition and LED Light Spectra on the Bioefficiency, Nutritional Compounds, and Morphology of Oyster Mushrooms

Abstract

The popularity of specialty mushrooms, such as oyster mushrooms (Pleurotus ostreatus), has increased as people become more interested in meatless and nutrient-dense foods. Specialty mushroom production is a growing industry, and production is mainly within controlled environment agriculture facilities, where humidity, temperature, CO2, and lighting are tightly controlled. Oyster mushrooms can colonize and thrive on various waste substrates, transforming agricultural residues and organic byproducts into nutrient-rich biomass. In this study, P. ostreatus was inoculated on two substrates consisting of a 70/30 mixture of straw/cottonseed or straw/mesquite pod and placed under one of three light spectra: blue (450 nm), red (625 nm), or white (broad spectrum). Bioefficiency, nutritional content, and morphology were measured at harvest. The results demonstrated that substrate composition was a positive driver in bioefficiency, beta-glucan content, crude protein content, amino acid content, and total antioxidant content in the fruiting bodies of P. ostreatus with consistently statistically significant results. LED exposure did not have significant effects in most cases. Regarding morphology, blue and white light exposure increased cap size but decreased the number of caps produced per cluster. Red light encouraged the development of clusters with significantly smaller caps but with a greater number of caps per cluster.