Enhancing the Nutritional Value and Antioxidant Activity of <i>Auricularia polytricha</i> Through Efficient Utilization of Agricultural Waste

<i>Auricularia polytricha</i>, a nutritious edible wood-rotting mushroom, faces cultivation challenges due to the limited availability of wood chips. It is urgent to find suitable flat substitutes to replace the current material. This study explores the use of 12 types of agricultural waste as alternative growth substrates, analyzing their effects on the physiological and biochemical characteristics of both mycelia and fruiting bodies. The agricultural waste that demonstrated greater suitability for the growth of <i>A. polytricha</i> was then selected as a substrate to evaluate its effect on the nutritional composition and antioxidant capacity of the fruiting bodies. The research findings have highlighted the potential for cotton straw, coix seed straw, and wheat straw to serve as the most efficient substrates in the cultivation of <i>A. polytricha</i>. The utilization of agricultural waste as a growth medium has been found to markedly enhance the activity of enzymes such as laccase, cellulase, and polyphenol oxidase within the mycelia, resulting in a significant reduction of the cultivation cycle by 16 days. These substrates also improved the nutritional composition of fruiting bodies, increasing crude fat, crude protein, total sugars, and mineral contents of iron (Fe) and zinc (Zn) in the fruiting bodies, with increases of 1.6-fold, 2.6-fold, 2.2-fold, fourfold, and sevenfold, respectively. Additionally, the in vitro antioxidant activity of <i>A. polytricha</i> was assessed, revealing an enhancement in the DPPH free radical scavenging ability by up to 36.06%. This study highlights the utilization of agricultural waste to enhance the nutrient profile of <i>A</i>. <i>polytricha</i>, providing innovative approaches for optimizing its production. Additionally, it offers significant insights into advancing technologies related to "transforming wood-rotting mushrooms into agents for straw degradation."