Abstract The effects of a water-soluble polysaccharide from Oudemansiella radicata (ORWP) on the postharvest quality of Pleurotus ostreatus were investigated. In the present work, oyster mushroom was divided into four groups which were treated separately with distilled water (control), and ORWP at 5, 10 and 15 g L−1 concentration, respectively, and kept at 4 ℃ for 15 d. The results showed that treatment with ORWP was effective in maintaining the sensory quality of oyster mushrooms. Mushrooms that were ORWP-coated displayed, compared to the control, reduction in the following parameters: weight loss, relative electrolyte leakage, phenol peroxidase (PPO) activities and malondialdehyde (MDA) content. In addition, ORWP-coated mushrooms maintained activities of superoxide dismutase (SOD) and catalase (CAT), contents of ascorbic acid, carbohydrate, soluble protein and phenolic compounds which were all higher than those of the control. Furthermore, the antifungal activity and underlying mechanisms of ORWP against Penicillium digitatum were investigated. The minimum inhibitory concentration (MIC) was 0.25 g L-1 and the minimum fungicidal concentration (MFC) was 1.00 g L−1. A combination of hyphal membrane permeability analysis, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the antifungal activity of ORWP was attributed to disruption of hyphal cell membrane integrity, leading to leakage of intracellular materials, and impaired cellular metabolism, thereby thwarting the growth of P. digitatum. Therefore, ORWP is a promising preservative agent for postharvest oyster mushrooms and could be used as an inhibitor of fungi in food and medicine.

中文翻译：

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Oudemansiella radicata 多糖对平菇（Pleurotus ostreatus）采后品质的影响及其对指状青霉的抗真菌活性

摘要 研究了Oudemansiella radicata 水溶性多糖(ORWP) 对平菇采后品质的影响。在目前的工作中，平菇分为四组，分别用蒸馏水（对照）和 ORWP 分别以 5、10 和 15 g L-1 的浓度处理，并在 4 ℃下保存 15 d。结果表明，ORWP处理可有效维持平菇的感官品质。与对照相比，ORWP 涂层的蘑菇显示出以下参数的减少：体重减轻、相对电解质泄漏、苯酚过氧化物酶 (PPO) 活性和丙二醛 (MDA) 含量。此外，ORWP 涂层蘑菇保持了超氧化物歧化酶 (SOD) 和过氧化氢酶 (CAT) 的活性、抗坏血酸、碳水化合物、可溶性蛋白质和酚类化合物均高于对照。此外，研究了 ORWP 对指状青霉的抗真菌活性和潜在机制。最低抑菌浓度 (MIC) 为 0.25 g L-1，最低杀菌浓度 (MFC) 为 1.00 g L-1。菌丝膜通透性分析、扫描电子显微镜 (SEM) 和透射电子显微镜 (TEM) 的组合表明，ORWP 的抗真菌活性归因于菌丝细胞膜完整性的破坏，导致细胞内物质的泄漏和细胞代谢受损，从而阻碍了 P. digitatum 的生长。因此，ORWP 是一种很有前途的采后平菇防腐剂，可用作食品和药物中的真菌抑制剂。