外源水杨酸处理对贮藏期桃果实褐变的影响

Effect of Exogenous Salicylic Acid on Browning of Peach Fruit during Storage

以中华寿桃果实为试材,研究在(1±0.5)℃、相对湿度(90±5)%冷藏条件下不同浓度水杨酸(SA)处理(1.25,2.50,5.00 mmol/L)对桃果实褐变的影响。试验分别测定了与褐变有关的果肉色泽、果实硬度、PPO和LOX活性、H2O2、·O2-、MDA和褐变指数及其值的变化。试验结果表明,SA能一定程度维持中华寿桃果肉色泽,减缓果实硬度下降速度,能降低果实中PPO和LOX活性。在活性氧代谢方面,SA能降低果肉组织中·O2-含量水平,提高贮藏前期果实组织中H2O2含量,维持活性氧较高代谢平衡。SA能够减轻MDA对细胞膜的伤害,维持细胞膜稳定性。与对照相比,水杨酸能显著降低果实褐变指数,抑制果肉褐变,但在对果实褐变指数的影响方面,水杨酸处理各水平间无极显著差异。

Zhonghuashoutao peach fruits were treated with salicylic acid（ SA） at the concentration of 1. 25,2. 50, 5. 00 mmol / L and effect of SA on browning in peach fruit during storage under（ 1 ± 0. 5） ℃ and RH（ 90 ± 5） % was studied. The experiment items respectively were peach flesh color and luster,firmness,polyphenoloxidase and lipoxygenase activity,the content of hydrogen peroxide and malondialchehyche,production rate of superoxide anion in peach pulp tissue related with fruit browning. The results showed that SA not only could retard the rate of peach fruit firmness descending to a certain degree,but also reduce the activity of polyphenoloxidase and lipoxygenase. SA also could reduce production rate of superoxide anion and enhance content of hydrogen peroxide at the earlier stage of storage. It could remain higher balance of reactive oxygen species metabolism. In addition,SA acid might alleviate the harm of malondialchehyche on cell membrane and keep its stability. SA reduced browning index obviously compared to control and restrained the development of fruit browning,but all SA treatments had no significant difference on browning index.