基于GC-MS分析两种梨蜡质差异对果实营养品质的影响

为探究发育阶段梨果实蜡质与果实营养指标的相关关系，选择外观差异明显的金坠梨和鸭梨，利用气相色谱-质谱（GC-MS）分析盛花后60 d的两种梨蜡质组分，并测定果实不同部位总酚和黄酮的含量，利用主成分分析（PCA）和相关性分析找到两者的关联。结果表明，2种梨果实中共鉴定出25种蜡质组分：C22-C29烷烃、C22-C28醇、C28-C34醛和7种三萜。金坠梨中C29烷烃、C28醇、C32醛、C34醛和Urs-12-en-28-al, 3-(acetyloxy)-, (3β)-等主要成分及脂肪族、三萜类和总蜡质等含量均低于鸭梨中的含量。金坠梨果皮总酚和果心黄酮含量低于鸭梨中的含量，但果心总酚含量却高于鸭梨中的含量。PCA表明，总蜡质、三萜类和脂肪醇代表两种梨果皮营养特征，而烷烃、脂肪醛和脂肪族蜡质代表两种梨果心营养特征。以上表明盛花后60 d，金坠梨和鸭梨果实蜡质组分与果实不同部位总酚和黄酮含量具有一定相关性。

Effect of difference in two kinds of pear wax on nutritional quality of fruit based on GC-MS

In order to explore the correlation between fruit wax and fruit nutritional indexes at the development stage, 'jinzhui' and 'yali' pear with obvious differences in appearance were selected to analyze the 2 wax components at 60 d after flowering by GC-MS. The contents of total phenols and flavonoids in different parts of the fruit were determined. The correlation between them was found by principal component analysis (PCA) and correlation analysis. The results showed that a total of 25 wax components were identified in 2 kinds of pear fruits: C22-C29 alkanes, C22-C28 alcohols, C28-C34 aldehydes and 7 triterpenoids. The contents of C29 alkane, C28 alcohol, C32 aldehyde, C34 aldehyde, and Urs-12-en-28-al, 3-(acetyloxy)-, and (3β)-), etc. and the aliphatic, triterpenoids and total wax in 'jinzhui' pear were all lower than those in 'yali' pear. The contents of total phenols in the peel and flavonoids in the core of 'jinzhui' pear were lower than those in 'yali' pear, but the contents of total phenols in the core of 'jinzhui' pear was higher than that in 'yali' pear. PCA showed that total waxes, triterpenoids and fatty alcohols represented the nutritional characteristics of 2 kinds of pear peel, while alkanes, fatty aldehydes and aliphatic waxes represented the nutritional characteristics of 2 kinds of pear core. The above results showed that there was a certain correlation between waxy components of 'jinzhui' and 'yali' pear fruits and the contents of total phenols and flavonoids in different parts of fruits after flowering for 60 d.