外源褪黑素处理对采后火龙果贮藏品质和活性氧清除能力的影响

王斌; 袁晓; 林冲; 王欣悦; 刘堂茂; 曹秋艳

doi:10.13386/j.issn1002-0306.2023120053

外源褪黑素处理对采后火龙果贮藏品质和活性氧清除能力的影响

Effects of Exogenous Melatonin Treatment on Storage Quality and ROS Scavenging Capacity of Harvested Pitaya Fruit

摘要

摘要: 为研究外源褪黑素（melatonin，MT）处理对采后火龙果的保鲜效果，以不同浓度（0.05、0.10和0.50 mmol/L）MT处理采后火龙果果实，并测定其贮藏品质和活性氧清除能力。结果表明：外源MT处理的保鲜效果与其浓度有关，相较于0.05 mmol/L和0.50 mmol/L，0.10 mmol/L MT处理能显著地抑制果实鳞片黄化，降低失重率，延缓总可溶性固形物和可滴定酸含量的下降，降低腐烂率。0.10 mmol/L MT处理还显著地提高了过氧化氢酶、过氧化物酶和抗坏血酸过氧化物酶活性及总抗氧化能力，增强对DPPH·和超氧阴离子自由基的清除能力。以上结果表明MT处理通过提高抗氧化酶活性及时清除衰老过程中产生的活性氧，缓解活性氧对采后火龙果造成的氧化损伤。

Abstract: To investigate preservative effects of exogenous melatonin (MT) treatment on pitaya fruit, different concentrations (0.05, 0.10, and 0.50 mmol/L) of MT were used to treat harvested pitaya fruit, and the storage quality and scavenging capacity of reactive oxygen species (ROS) of MT treatment were measured. The results showed that preservative effects of MT depended on treatment concentration, and 0.10 mmol/L MT treatment significantly enhanced storage quality in relative to 0.05 mmol/L and 0.50 mmol/L concentrations. 0.10 mmol/L MT treatment effectively inhibited scale yellowing, reduced weight loss, delayed the decline in total soluble solids and titratable acid content, as well as minimized decay rate. Furthermore, 0.10 mmol/L MT treatment significantly enhanced the activities of catalase, peroxidase, and ascorbate peroxidase, along with the total antioxidant capacity, thereby enhancing the scavenging ability to DPPH· and superoxide anion radicals. The above results suggested that MT treatment enhanced antioxidant enzyme activity, facilitating the timely removal of ROS generated during fruit senescence and reducing oxidative damages caused by ROS.