葡萄采后果梗抗氧化系统与褐变的关系

Relationship between Antioxidant Systemand Browning of Postharvest Grape Rachis

摘要:

以新疆红提、木纳格葡萄为试材，在10±0.5 ℃的温度条件下，分析贮藏期间果梗之间的差异，研究果梗褐变与抗氧化系统变化的相关性。结果表明：贮藏至第6 d，红提和木纳格葡萄果梗的总酚含量分别为5.37、5.41 A280 nm/g；PPO和POD的活性分别为0.21、1.09和0.82、0.11 U/g。红提葡萄果梗的SOD活性是26.98 U/g、CAT活性是64.44 U/g、APX活性是30.89 U/g，分别是木纳格葡萄的1.03倍、2.19倍和1.85倍。红提葡萄果梗的褐变指数、超氧阴离子（O2-·）、H2O2含量、相对电导率、MDA含量及类黄酮含量显著低于木纳格葡萄（p<0.05），分别低4.04%、43.17%、11.55%、43.32%、13.78%和30.94%。红提和木纳格葡萄果梗褐变指数均与相对电导率、丙二醛含量、总酚、类黄酮及H2O2含量呈现显著正相关（p<0.05），与PPO活性呈正相关（p>0.05)；红提葡萄果梗褐变指数与POD活性、CAT活性有良好的相关性（p<0.05)；木纳格葡萄果梗褐变指数与PAL活性及SOD活性有较好的相关性（p<0.05)。因此，葡萄品种与抗氧化系统密切相关，导致果梗褐变进程有所不同。

Abstract:

Xinjiang Red Globe grape and Munage grape were used as test materials, which stored at a temperature of 10±0.5 ℃. The differences between fruit rachis were analyzed in storage. The correlation between the browning of fruit rachis and the changes of antioxidant systems were studied. The results showed that after storage to the 6th day, the total phenol content of Red Globe grape rachis and Munage grape rachis were respectively 5.37 and 5.41 A280 nm/g. The activities of PPO and POD were respectively 0.21, 1.09 and 0.82, 0.11 U/g. The activity of SOD, CAT and APX in Red Globe grape rachis were respectively 26.98 U/g, 64.44 U/g, 30.89 U/g, which were respectively 1.03 times, 2.19 times and 1.85 times of those in Munage grape rachis. The browning index, superoxide anion (O2-·), relative conductivity of H2O2 content, MDA content and flavonoid content of Red Globe Grape rachis were significantly lower than those of Munage grape rachis (p<0.05), which were 4.04%, 43.17%, 11.55%, 43.32%, 13.78% and 30.94% lower respectively. Through correlation analysis, the browning index of the Red Globe grape and the Munage grape rachis were significantly positively correlated with the relative conductivity, malondialdehyde content, total phenols, flavonoids and H2O2 content (p<0.05), and PPO activity is positively correlated (p>0.05). Red Globe grape rachis browning index has a good correlation with POD activity and CAT activity (p<0.05). However, Munage grape rachis browning index has a good correlation with PAL activity and SOD activity (p<0.05). Therefore, grape varieties are closely related to the antioxidant system, leading to different browning process of fruit rachis.