1-MCP和UV-C处理对采后苹果抗氧化活性的影响
Effect of 1-MCP and UV-C on Antioxidant Capacity in Apple (Malus pumila Mil.) Fruit during Storage
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摘要: 以红富士苹果为试材,研究了2 μL/L 1-MCP和2.5 kJ/m2短波紫外线(UV-C)处理对苹果在4 ℃下贮藏过程中品质、次生代谢物合成以及抗氧化能力的影响。结果表明:1-MCP和UV-C处理后的苹果经贮藏28 d后,能提高果实中抗坏血酸含量,增加了酚类物质和类黄酮物质的含量,从而较好的保持了果实的营养品质和贮藏特性。1-MCP联合UV-C处理显著(p<0.05)提高了苹果果实的苯丙氨酸解氨酶(PAL)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的活性,降低了H2O2含量和O2-·的产生速率。2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)法和1,1-二苯基-2-三硝基苯肼(DPPH)法均表明1-MCP联合UV-C处理显著提高了苹果果实的抗氧化能力,且总酚和类黄酮含量与抗氧化能力呈极显著正相关(p<0.01),相关系数最高分别达0.879和0.715。由此说明,1-MCP和UV-C处理能提高苹果果实的抗氧化能力,改善果实的营养品质,延缓果实的衰老,研究结果为苹果的贮藏保鲜提供了一定的实验依据。Abstract: Effects of 2 μL/L 1-Methylcyclopropene (1-MCP) and 2.5 kJ/m2 UV-C radiations on quality, secondary metabolism and antioxidant capacity of apple fruit were evaluated. Results showed that 1-MCP and UV-C promoted accumulation of ascorbic acid, phenolic and flavonoids, and maintained storage quality. Combined effect of 1-MCP and UV-C radiation treatment significantly improved activities of PAL, SOD and CAT, reduced H2O2 content and O2-·generation rate (p<0.05). Two methods of ABTS and DPPH proved that 1-MCP combined with UV-C significantly enhanced the antioxidant capacity of apple fruits. The contents of phenolic and flavonoids were significantly correlated with antioxidant activity (p<0.01) and the correlation coefficients were 0.879 and 0.715 respectively. These results suggested that 1-MCP and UV-C irradiation could be used to maintain postharvest quality, enhance antioxidant capacity and delay ripening and senescence in apple fruit. The results provide an experimental evidence for apple storage.