低频极化电场处理对草莓采后抗病性能及贮藏品质的作用

Effects of Low Frequency Polarized Electric Field Treatment on Postharvest Disease Resistance and Storage Quality of Strawberries

摘要:

探究了低频极化电场（Low-Frequency Polarized Electric Field, LFPEF）处理对采后草莓贮藏期间的抗病性能及品质的影响。结果表明，与对照组相比，LFPEF处理提高了贮藏末期草莓果实硬度（53.10%）、可溶性固形物含量（6.50%）和可溶性糖含量（7.72%），将失重率从4.96%降低至3.30%。此外，LFPEF处理降低了草莓灰霉病发病率及病斑直径，提高了采后草莓果实贮藏品质。在贮藏第6天，相比对照组，LFPEF处理使得过氧化氢酶（Catalase, CAT）、多酚氧化酶（Polyphenol Oxidase, PPO）活性下降32.9%和6.95%，超氧化物歧化酶（Superoxide Dismutase, SOD）、抗坏血酸过氧化物酶（Ascorbate Peroxidase, APX）和谷胱甘肽还原酶（Glutathione Reductase, GR）活性分别上升84.77%、63.15%、40.63%，诱导了H2O2迸发，促进了抗坏血酸（Ascorbic Acid, ASA）、谷胱甘肽（Glutathione, GSH）、总酚和类黄酮等抗氧化物质积累，从而提高了机体抗氧化能力。此外，LFPEF降低了草莓果实纤维素酶（Cellulase, CEL）、β-半乳糖苷酶（β-galactosidase，β-GAL）、果胶甲酯酶（Pectin Methylesterase，PME）、多聚半乳糖醛酸酶（Polygalacturonase, PG）活性，使得贮藏第6天时草莓原果胶及总果胶含量分别比对照组增加21.12%和70.21%。综上，LFPEF处理通过激活抗氧化系统和维持细胞壁结构，提高采后草莓抗病性，维持了草莓采后品质，对于采后草莓贮藏有一定参考价值。

Abstract:

The effects of low-frequency polarized electric field (LFPEF) treatments on the disease resistance and quality of postharvest strawberries during storage were investigated. The results showed that, compared with the control group, LFPEF treatment increased the hardness, soluble solid content, and soluble sugar content of strawberry fruits by 53.10%, 6.5%, and 7.72%, respectively, and reduced the weight loss rate from 4.96% to 3.30% at the end of storage. In addition, LFPEF treatment reduced the incidence of gray mold and the diameter of the lesions in postharvest strawberries and improved the quality of the strawberries after harvest. On day 6 of storage, compared with the control group, LFPEF treatment decreased the activities of catalase and polyphenol oxidase by 32.9% and 6.95%, while the activities of superoxide dismutase, ascorbate peroxidase, and glutathione reductase increased by 84.77%, 63.15%, and 40.63%, respectively. This treatment induced hydrogen peroxide (H2O2) burst and promoted the accumulation of antioxidant substances such as ascorbic acid, glutathione, total phenols, and flavonoids, thereby fortifying the antioxidant capacity of strawberries. Additionally, LFPEF treatment inhibited the activities of cellulase, β-galactosidase, pectin methylesterase, and polygalacturonase and improved the contents of protopectin and total pectin by 21.12% and 70.21%, respectively, in strawberries. In conclusion, LFPEF treatment could improve disease resistance and maintain the quality of postharvest strawberries by activating the antioxidant system and preserving the cell wall structure. These findings provide valuable insights for postharvest storage of strawberries.