钙处理对‘南果梨’果实香气合成底物及关键酶活性的影响

Effects of calcium treatment on substrates and key enzyme activities related to aroma synthesis in ’Nanguoli’ pear fruits

为了研究钙处理调控‘南果梨’果实香气合成的生理机制,试验以商熟期前15 d钙处理‘南果梨’为材料,对梨果实成熟、后熟过程中香气代谢底物组成、含量及香气合成关键酶活性进行了研究。结果表明,‘南果梨’果实中共分离鉴定出可溶性糖4种,有机酸6种,氨基酸15种,脂肪酸32种。钙处理显著提高了‘南果梨’果实可溶性糖、氨基酸和脂肪酸的含量,其中商熟期钙处理‘南果梨’果实亚油酸含量较对照提高了123.33%,亚麻酸含量较对照提高了639.81%。钙处理显著提高了‘南果梨’果实ADH、PDC和LOX的活性,其中商熟期ADH的活性较对照提高了317.58%。综合认为,钙处理通过提高代谢底物(如亚油酸、亚麻酸)的含量及ADH、PDC和LOX等酶的活性来提高‘南果梨’果实挥发性香气物质的生物合成。

In order to study the physiological mechanism of pre-harvest calcium treatment improving aroma of ’Nanguoli’ pear(Pyrus ussariensis) fruit, the metabolic substrates, contents and key enzyme activities related to aroma synthesis were determinted in ’Nanguoli’ pear fruit treated with calcium at 15 days before harvest. A total of four kinds of soluble sugars, six kinds of organic acids, 15 kinds of amino acids and 32 kinds of fatty acids were separated and identified in ’Nanguoli’ pear fruit. Calcium treatment significantly increased the soluble sugars, amino acids and fatty acids content of ’Nanguoli’ pear fruit. The linoleic acid content of ’Nanguoli’ pear fruits treated with calcium at commercial ripening stage was 123.33% higher than that of the control, and the linolenic acid content was 639.81% higher than that of the control. Preharvest calcium treatment significantly increased the activities of ADH, PDC and LOX in ’Nanguoli’ pear fruits, and the activities of ADH in commercial ripening stage increased by 317.58% compared with the control. It was concluded that calcium treatment could improve the biosynthesis of volatile aroma compounds in ’Nanguoli’ pear fruit by increasing the contents of metabolic substrates(such as linoleic acid and linolenic acid) and the activities of ADH, PDC and LOX.