Biochemical Composition, Nutritional Profile, Bioactive Compound Content, Antioxidant Activity, and Technological Potential of Mycelium from Pleurotus ostreatus (Shimeji)

Pleurotus ostreatus (shimeji) is an edible mushroom widely recognized for its nutritional value and production of bioactive compounds. In addition to its fruiting body, mycelial biomass has emerged as a promising and sustainable alternative to produce bioactive compounds under controlled cultivation conditions. This study evaluated the nutritional composition, texture profile, biochemical composition, phenolic compounds, and antioxidant properties of the mycelium of P. ostreatus. Nutritional parameters were determined by FoodScan™ (NIR), while biochemical composition was assessed through spectrophotometric quantification of soluble proteins, free amino acids, reducing sugars, and total carbohydrates. Texture Profile Analysis (TPA) was performed to characterize the mechanical and technological properties of the mycelial biomass. Total phenolic compounds were quantified using the Folin–Ciocalteu method, and individual phenolics were identified by HPLC-DAD. Antioxidant activity was evaluated by ABTS, DPPH, TEAC, and hydroxyl radical scavenging assays. The mycelium exhibited high moisture content and relevant protein levels, as well as a rigid structural profile characterized by elevated hardness and gumminess. Biochemical characterization revealed considerable concentrations of soluble proteins and free amino acids, together with detectable levels of reducing sugars and total carbohydrates. The aqueous extract showed high total phenolic content and expressive antioxidant activity, with gallic acid identified as the predominant phenolic compound, followed by ferulic acid. The extracts also demonstrated efficient radical scavenging capacity in ABTS, DPPH, and hydroxyl radical assays. These findings highlight P. ostreatus mycelium as a sustainable source of bioactive compounds with potential applications as a functional ingredient in food, nutraceutical, and biotechnology sectors, reinforcing its role within circular bioeconomy strategies.