Effect of 60Co-irradiation on Postharvest Quality and Selected Enzyme Activities of Hypsizygus marmoreus Fruit Bodies

• Published in: Journal of agricultural and food chemistry 2007-10, Vol.55 (20), p.8126-8132
• Main Authors: Xing, Zengtao, Wang, Yaosong, Feng, Zhiyong, Zhao, Zhihui, Liu, Xinghua
• Format: Article
• Language: English
• Subjects: 60Co irradiation; Agaricales - chemistry; Agaricales - enzymology; Agaricales - radiation effects; Biological and medical sciences; Chem Process/Storage; Cobalt Radioisotopes; Dose-Response Relationship, Radiation; enzyme activity; firmness; food analysis; food composition; Food industries; Food Irradiation; Food Preservation - methods; food storage; Fruit and vegetable industries; fruit body quality; fruiting bodies; Fruiting Bodies, Fungal - chemistry; Fruiting Bodies, Fungal - enzymology; Fruiting Bodies, Fungal - radiation effects; Fundamental and applied biological sciences. Psychology; gamma radiation; Hypsizygus marmoreus; malondialdehyde; mushrooms; Nutritive Value; postharvest physiology; postharvest senescence; Quality Control; storage quality; Time Factors
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf070941w

Hypsizygus marmoreus fruit bodies were exposed to different doses of 60Co γ-irradiation, stored at 4 °C and 65–70% relative humidity, and various physiological changes associated with postharvest deterioration, as well as the activities of selected enzymes widely considered to play a role in the process of senescence, were monitored over a subsequent storage period of 25 days. Exposure to 0.8 kGy irradiation was clearly beneficial in maintaining the postharvest appearance of the mushroom sporophores compared to non-irradiated samples and fruit bodies exposed to higher doses (1.2–2.0 kGy) of irradiation. Samples treated with 0.8 kGy also exhibited smaller initial declines in soluble protein, smaller increases in reducing sugar content, and lower levels of malondialdehyde accumulation during the early storage period. Smallest increases in proteinase activity were recorded in samples dosed with 0.8 and 2.0 kGy, and levels of superoxide dismutase were significantly higher in samples exposed to 0.8 kGy compared with non-irradiated controls. Large initial increases in catalase activity were detected in samples irradiated with 0.8, 1.2, and 1.6 kGy and, although enzyme levels gradually decreased in all samples during further storage, residual levels after 25 days were still severalfold higher in irradiated samples compared with controls. The data increase the current understanding of the effects of γ-irradiation on the biochemical changes associated with postharvest senescence and should lead to more targeted strategies for reducing postharvest quality loss in H. marmoreus and other mushrooms.