CaCl2对采后不同成熟度冬枣抗氧化及细胞壁代谢的影响

Effect of CaCl2 Treatment on Antioxidant Capacity and Cell Wall Metabolism of Post-harvest Jujube Fruits at Different Maturity Stages

摘要:

为探讨CaCl2处理对不同成熟度冬枣（Zizyphus Jujuba Mill. cv. Dongzao）抗氧化能力及细胞壁代谢的影响，试验采用1%和2% CaCl2浸泡处理白熟期（WM）和半红期（HM）冬枣果实，以水处理为对照，测定20±2 ℃贮藏过程中果实硬度、过氧化氢（H2O2）、丙二醛（MDA）、超氧化物歧化酶（SOD）、过氧化物酶（CAT）、抗坏血酸（AsA）、还原型谷胱甘肽（GSH）、多聚半乳糖醛酸酶（PG）以及细胞壁组分（水溶性果胶（WSP）、离子结合果胶（ISP）和共价结合果胶（CSP））变化。结果表明，在贮藏过程中1%和2% CaCl2处理可显著延缓WM和HM期果实硬度下降，抑制H2O2和MDA积累，维持较高水平的SOD和CAT活性以及AsA和GSH含量，同时，降低PG活性以及WSP和ISP含量，增加CSP含量，其中1% CaCl2处理对HM期果实作用效果最显著，通过提高其抗氧化活性和抑制细胞壁降解过程，使其在贮藏期间保持较好的果实品质。

Abstract:

Post-harvest jujube (Zizyphus Jujuba Mill. cv. Dongzao) fruits at white maturity (WM) and half-red maturity (HM) stage were used to investigate the effects of CaCl2 treatment on the antioxidant capacity and cell wall metabolism of post-harvest jujubes at different stages of maturity. WM and HM fruits were treated with 1% and 2% (m/V) CaCl2, while control fruits were immersed in water. During storage at 20°C ± 2°C, parameters such as fruit firmness, hydrogen peroxide (H2O2), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), ascorbic acid (AsA), glutathione (GSH), polygalacturonase (PG), and cell wall components (water-soluble pectin [WSP], ionic-soluble pectin [ISP], and covalent-soluble pectin [CSP]) were evaluated. The results showed that treatment with 1% and 2% CaCl2 significantly delayed the decrease in fruit firmness, inhibited the accumulation of H2O2 and MDA, and maintained high levels of SOD and CAT activity as well as AsA and GSH content. Meanwhile, PG activity and content of WSP and ISP were decreased, while CSP content was increased. Overall, 1% CaCl2 treatment exhibited the most significant effect on HM jujube fruits by enhancing antioxidant activity and inhibiting cell wall degradation, thus maintaining fruit quality during storage.