目的 探究纳他霉素与ε-聚赖氨酸复配对火龙果贮藏品质的协同作用，为火龙果保鲜技术提供参考。方法 以红肉火龙果为材料，采用3个复配浓度(纳他霉素与ε-聚赖氨酸的复配比例为1∶1，质量浓度分别为400、800、1 200 mg/L，分别记作处理1、处理2、处理3)处理火龙果，于温度(25±2)℃、相对湿度(75±5)%下贮藏，对火龙果的感官指标、内容物和抗氧化酶活性的变化进行分析。结果 贮藏0~12 d，与对照组相比，3个处理组的质量损失率明显降低，降低幅度为45.50%~57.06%(P＜0.05);腐烂率明显降低，降低幅度为16.31%~38.30%;硬度和L^*的降低幅度分别为8.88%~21.02%、4.25%~6.24%;可溶性固形物(TSS)含量和呼吸强度的降低幅度分别为3.13%~11.79%、2.41%~46.76%。在贮藏10 d期间，丙二醛(MDA)含量显著降低(19.47%~33.98%);超氧化物歧化酶(SOD)、过氧化物酶(POD)活性分别显著增加了1.09%~27.59%、1.11%~32.77%。在贮藏8 d内，过氧化氢酶(CAT)活性增加了11.52%~36.19%;在贮藏12 d时，抗坏血酸过氧化氢酶(APX)活性显著提高了1.73%~23.98%。结论 3种处理均可延缓火龙果质量损失率和腐烂率的上升，减缓果皮L^*和硬度的下降速度，降低呼吸强度和MDA含量，提高SOD、CAT、POD、APX活性。其中，处理1(即400 mg/L ε-PL+400 mg/L Natamycin)更好地维持了火龙果的商业品质。

The work aims to explore the synergistic effect of natamycin and ε-polylysine on the storage quality of pitaya to provide reference for the preservation technology of pitaya. The red-fleshed pitaya was used as the material, and the pitaya was treated with three compound concentrations (the ratio of natamycin to ε-polylysine was 1∶1 and the concentrations were 400, 800 and 1 200 mg/L, respectively, which were recorded as treatment 1, treatment 2 and treatment 3, respectively), and stored at (25±2) ℃ and (75±5%) RH. The changes of sensory indexes, contents and antioxidant enzyme activities of pitaya were analyzed. The results showed that compared with the control group, the mass loss rate of the three treatment groups was significantly reduced by 45.50%-57.06% (P<0.05), and the decay rate was significantly reduced by 16.31%-38.30%. The hardness and L value of pitaya was decreased by 8.88%-21.02% and 4.25%-6.24%, respectively. The total soluble solids (TSS) content and respiratory intensity of pitaya were decreased by 3.13%-11.79% and 2.41%-46.76%, respectively. During storage of 10 d, the content of malondialdehyde (MDA) was decreased significantly by 19.47%-33.98%. The activities of superoxide dismutase (SOD) and peroxidase (POD) were significantly increased by 1.09%-27.59% and 1.11%-32.77%, respectively. The activity of catalase (CAT) increased by 11.52%-36.19% within 8 d of storage. The activity of ascorbate catalase (APX) was significantly increased by 1.73%-23.98% at 12 d of storage. Comprehensive analysis shows that the three treatment groups can delay the increase of weight loss rate and decay rate of pitaya, slow down the decrease of peel L value and hardness, reduce respiratory intensity and MDA content, and increase SOD, CAT, POD and APX activities. Among them, treatment 1 (400 mg/L ε-PL+400 mg/L natamycin) can better maintain the commercial quality of pitaya.