人为调节荔枝果皮有机自由基及其与果皮变褐的可能关系  

ARTIFICIAL REGULATION OF ORGANIC FREE RADICALS IN PERICARP OF LITCHI AND ITS POSSIBLE RELATION TO PERICARP BROWNING

作　　者：林植芳[1] 林桂珠[1] 孙谷畴[1] 陈芳[1] 彭长连[1] 刘淑娴[1] 

机构地区：[1]中国科学院华南植物研究所,广州510650

出　　处：《实验生物学报》1994年第4期383-388,共6页Acta Biologiae Experimentalis Sinica

摘　　要：荔枝果实以10ppm的6-BA、NAA、GA_3+NAA或PVP(1%)+NAA处理2min,1℃贮藏8天后再于室温放2天。EPR分析表明果皮的有机自由基(g因子2.0030)比对照低9%—22%,花色素苷含量高5%—46%。离体果皮小圆片经同法浸泡1h或16h,有机自由基反而比对照高。O_2^-的捕获剂Tiron和抗氧化剂PG+CA处理果皮小圆片1h,有机自由基降低8%—11%,处理16h则自由基高于对照。邻苯二酚(pH 8.4)和H_2O_2加速果色变褐,有机自由基增高10%—370%。果皮离体后自由基的EPR波谱特征也发生变化,除了一个g因子2.0026—2.0027的主峰外,尚出现另一个小峰。结果表明荔枝果皮褐变的部分原因是有机自由基增高之故。By treating the litchi fruit with 10 ppm of 6-BA, NAA, GA3+NAA or PVP (1%) +NAA solution for 2 min, followed storing at 1℃ for 8 days, then transferred to room temperature for 2 days, the organic free radicals level decreased by 9% -22% of control, whereas the total antho-cyanin content increased by 5%-46%. In contrast, when isolated pericarp discs were treated by above growth regulators for 1 h or 16 h at room temperature, the organic free radicals level were higher than the control. Catechol (at pH 8.4) and H2O2 showed an obvious promotion of organic free radicals formation (10%-370%), and re- sulted in the pericarp browning upon the test with pericarp discs. A nonsuperfine structure signal with g factor of 2.0030 was found in pericarp EPR spectra sampling from treated fruits. However, the pattern of EPR spectra from treated discs of pericarp was slightly different. Except a main signal with g factor of 2.0026, another small signal was also observed. The results indicated that organic radicals and color of litchi pericarp could be affected by growth regulator, antioxi-dant and oxidant. Browning of pericarp at least partially related to the increase of organic free radicals.

关 键 词：荔枝 果皮 有机自由基 褐变 

分 类 号：S667.101[农业科学—果树学]