Fresh water caltrop （Trapa acornis Nakano） fruits are very perishable and susceptible to browning, thus resulting in a short shelf life. In this study, fresh water caltrop fruits were coated with chitosan solutions at concentrations of 0.0, 1.0 g/ 100 mL and 2.0 g/100 mL, respectively, and stored at （4 ± 1）℃ and relative humidity of （90 ± 2）% for 15 days. Fresh weight loss, and the contents of vitamin C, total phenolics, total soluble sugar, sucrose, reducing sugar, total soluble solid and malondialdehyde （MDA）, as well as the activities of polyphenol oxidase （PPO）, ascorbate peroxidase （APX）, superoxide dismutase （SOD） and catalase （CAT） were determined periodically to evaluate the effect of chitosan coating on the quality and physiology of fresh water caltrop fruits during storage. The results showed that chitosan coating at concentrations of 1.0 g/100 mL and 2.0 g/100 mL significantly reduced the fresh weight loss of fruits, and retarded the decline of vitamin C, total phenolics, total soluble sugars, sucrose, reducing sugar and total soluble solid contents when compared with the control, thus maintaining fruit quality. Furthermore, chitosan coating at both concentrations also inhibited PPO activity, delayed the increase of APX and SOD activities, and decreased MDA accumulation when compared with the control. In conclusion, chitosan coating is effective in preserving the quality properties, delaying the senescence and prolonging the shelf life of water caltrop fruits.%以新鲜南湖菱果实为试材,研究壳聚糖涂膜对南湖菱果实贮藏期间品质和生理的影响。用1.0g/100mL和2.0g/100mL壳聚糖溶液对果实涂膜后,4℃±1℃、相对湿度（90±2）%条件下贮藏15d,测定果实贮藏期间质量损失率、VC、总酚、可溶性总糖、蔗糖、还原糖和可溶性固形物含量变化与多酚氧化酶（PPO）、抗坏血酸过氧化物酶（APX）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）比活力以及丙二醛（MDA）含量的变化。结果表明：1.0g/100mL和2.0g/100mL壳聚糖涂膜显著减少果实表面失水,减缓VC、总酚、可溶性总糖、蔗糖、还原糖和可溶性固形物含量下降,维持果实营养品质;同时抑制褐变酶PPO比活力,减缓抗氧化酶APX和SOD比活力上升,减少膜脂过氧化产物MDA积累。因此,1.0g/100mL和2.0g/100mL壳聚糖涂膜能够有效地保存果实营养物质,延缓果实衰老,可以作为安全廉价的保鲜方法应用于南湖菱果实贮藏保鲜。
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