Macronutrient composition, antioxidant and antibacterial properties of Pleurotus pulmonarius’s fruiting body vs. stem waste

¹ Faculty of Agro-based Industry, Universiti Malaysia Kelantan, 17600 Jeli, Kelantan, Malaysia
² Functional Agroproduct Research Group, Faculty of Agro-based-Industry, Universiti Malaysia Kelantan, 17600 Jeli, Kelantan, Malaysia
³ Institute of Food Security and Sustainable Agriculture (IFFSA), Universiti Malaysia Kelantan, 17600 Jeli, Kelantan, Malaysia

^* Corresponding author: azwanida@umk.edu.my

Abstract

The increasing cultivation of mushrooms has led to substantial waste production, ranging from 5-20% of total volume mushroom harvested. This study aimed to compare the macronutrient composition and bioactivities of oyster mushroom (Pleurotus pulmonarius), focusing on its stem waste versus fruiting bodies. Macronutrients analyzed include moisture, ash, fat, fiber, protein, and carbohydrates using proximate analysis. Antioxidant activity was assessed via DPPH and ABTS assays, while antimicrobial activity was evaluated using microdilution techniques. Results indicated that mushroom stem waste contained significantly higher levels of carbohydrates (46.2 ± 0.69%), ash (8.2 ± 0.04%), and fiber (15.4 ± 0.10%) compared to the fruiting bodies (carbohydrates: 38.1 ± 0.84%, ash: 6.7 ± 0.12%, fiber: 9.1 ± 0.02%). Conversely, the fruiting bodies exhibited superior antioxidant activity with IC50 values ranging from 166.1 to 503.5 μg/mL. Similar minimum inhibitory concentrations (MIC) were observed between both parts, except for E. coli, where the fruiting bodies showed an MIC of 2000 μg/mL compared to 1000 μg/mL for stem waste. In conclusion, this study highlights the bioactive potential of mushroom stem waste and further purification could enhance its suitability for diverse bioactive applications.