电子束辐照对猕猴桃品质及抗性系统的影响

以‘海沃德’猕猴桃为试材，人工接种灰葡萄孢菌（Botrytis cinerea）后采用高能电子束辐照处理，于0～1 ℃、相对湿度90%～95%条件下贮藏，每15 d取一次样，测定电子束辐照处理后果实冷藏期理化指标及抗性酶活力等指标，探究电子束辐照对猕猴桃贮藏品质的影响及对灰霉病的抑制效果，为电子束辐照猕猴桃防腐保鲜技术提供理论依据。结果表明，与对照组相比，电子束辐照处理能有效降低质量损失率，保持果实的可溶性固形物质量分数，抑制可滴定酸质量分数的下降，0.4 kGy辐照组类黄酮含量最高峰峰值升高25.52%；与对照组相比，电子束辐照组过氧化物酶、苯丙氨酸解氨酶和β-1,3-葡聚糖酶活力最高峰峰值升高，且0.8、1.2 kGy辐照组β-1,3-葡聚糖酶活力峰值首次出现的时间提前30 d，丙二醛含量提高，表明电子束辐照会引起轻微的果肉细胞膜脂质过氧化，其中以0.4 kGy辐照的果实品质变化小，诱导的果实抗性较强，说明适宜剂量的电子束辐照可以作为提升猕猴桃保鲜效果和抑制腐烂损耗的有效手段。

Effect of Electron Beam Irradiation on Quality and Resistance System of Kiwifruit

To provide a theoretical basis for developing an electron beam irradiation technique for the preservation of kiwifruit, this study investigated the effect of electron beam irradiation on the storage quality and gray mold of kiwifruit. Freshly harvested ‘Hayward’ kiwifruit were artificially infected with Botrytis cinerea, treated with high-energy electron beam irradiation, and then stored at 0–1 ℃ and relative humidity of 90%–95%. Samples were taken every 15 days to determine fruit physicochemical index and resistance-related enzyme activities. The results showed that compared with the untreated control, electron beam irradiation treatment effectively reduced the fruit mass loss, maintained the soluble solid content, and inhibited the decrease in titratable acid content. The peak value of flavonoids in the 0.4 kGy irradiation group increased by 25.52% in comparison with the control group. Electron beam irradiation increased the peak values of peroxidase (POD), phenylalanine ammonia-lyase (PAL) and β-1,3 glucanase (GLU) activity as compared with the control group, at 0.8 and 1.2 kGy doses advancing the first appearance of peak of β-1,3 glucanase activity by 30 days and elevating the content of malondialdehyde (MDA). This indicates that electron beam irradiation triggers slight lipid peroxidation in the cell membrane. Electron beam irradiation at 0.4 kGy dose caused only marginal changes in the fruit quality but induced strong fruit resistance. Accordingly, an appropriate dose of electron beam irradiation can be used as an effective means to improve the preservation of kiwifruit and inhibit the decay loss.