采后钙处理对梨果实钙的形态和果胶及相关代谢酶类影响的研究

Effects of Calcium Treatment on Calcium Forms, Pectin Content and Related Enzyme Activities in Harvested Pear Fruits

研究了黄花梨经浸钙处理后,果实钙形态转变及果胶含量、多聚半乳糖醛酸酶(PG)和果胶甲酯酶(PME)活力的变化,以及果实硬度的变化。结果表明:浸钙处理的果实总钙含量显著提高,其硬度明显高于对照,且有利于细胞膜透性的保持;梨果实中的NaCl溶性钙最多,其次是水溶性钙,醋酸溶性钙和HCl溶性钙含量较少。在果实贮藏21d时,水溶性钙含量有一个上升的过程,而NaCl溶性钙则有一个下降的过程。浸钙处理后,除醋酸溶性钙外,果实中的水、NaCl和HCl溶性钙含量均有显著的提高。浸钙处理明显抑制了果胶的降解进程与PG的活力,但对PME抑制作用不明显。浸钙处理能提高果实硬度可能与浸钙处理抑制了PG活力有关。

Harvested pear （Pyrus pyrifolia） fruits were dipped in calcium solution to investigate the effects of calcium chloride solution treatment on the content of pectin, the contents of different soluble calcium, the changes in activities ofpectinesterase （PME） and polygalacturonase （PG） and on the fruit firmness. The results showed that calcium solution treatment significantly increased total calcium content in fruits, improved fruit firmness and maintained permeability of cell membrane significantly. The content of NaCl soluble calcium was highest in treated fruits, followed by water-soluble calcium, calcium acerate and HCl-soluble calcium. An increasee in water-soluble calcium was observed on the 21 st day in treated fruits, while NaCl soluble calcium decreased. The contents of water-, NaCl- and HCl-soluble calcium increased significantly after calcium treatment except for acetic acid soluble calcium. Calcium treatment delayed degradation process of pectin and inhibited PG activity, but had no obviously inhibitory effect on PME activity. Effect of calcium treatment on fruit firmness was probably related with the inhibitory effect of PG activity.