减压贮藏对辽西鲜枣衰老的影响

Effects of Hypobaric Storage on Senescence of Jujube in the West of Liaoning

以辽西的朝阳大平顶枣、义县金丝小枣为试验材料,通过测定其生理生化指标的变化情况探讨枣果的衰老影响因素及减压贮藏效果。结果表明:枣果贮藏过程中,微红果逐渐转红,硬度下降,可滴定酸、Vc含量先上升后逐渐下降,还原糖含量逐渐上升。朝阳大平顶的Vc氧化酶活性由初始值0.31μg.g-1.min-1逐渐降低后又缓慢升高,最终又下降至0.2μg.g-1.min-1;多酚氧化酶活性变化与Vc氧化酶变化基本相同;金丝小枣与大平顶枣变化趋势相似。2种酶的变化趋势与Vc的损失和果肉的褐变现象相关性较小,表明它们不是影响Vc损失和果肉褐变从而引起枣果衰老的主要因素。减压处理能进一步延缓枣果硬度、可滴定酸、Vc及还原糖的变化速率,同时可抑制Vc氧化酶和多酚氧化酶活性,减缓了枣果中Vc损失与果肉褐变速度,延缓果实衰老过程,将金丝小枣贮藏期延长到90d,好果率可达90%以上。

The materials of the study are Chaoyang Dapingdingzao and Jinsi Xiaozao. The main factors affecting jujube senescence and the effect of hypobaric storage were studied through testing the physiological and biochemical change of jujube fruits. The results of the study showed that during fresh-keeping period the green jujube turned red little by little, the rigidity value and the crisp fruit rate decreased slowly. The titratable acid content and ascorbic acid content in jujube increased slowly, then decreased slowly. The reductive sugar increased gradually. For Chaoyang Dapingding, the activity of ascorbic oxidase changed from 0.31g·g^-1·min^-1 to 0.2g·g^-1·min^-1. The polyphenol oxidase activation change was similar to the tendency of the ascorbic oxidase, The tendency of Jinsi Xiaozao was similar, During the storage period the activities of both enzymes varied gently and had little relation with the loss of ascorbic acid and the browning of flesh in jujube which indicated that they were not the main factors affecting the loss of ascorbic acid and the browning of flesh, Hypobaric storage can decrease the change speed of rigidity, titratable acid, ascorbic acid and reductive sugar, restrain furtherly the activities of ascorbic acid oxidase and polyphenol oxidase, delay the progress of senescence, extend fresh-keeping period to 90 days, keep the crisp fruit rate to 90%,