油梨果皮着色与关键酶活性相关性分析

Correlation Analysis between Coloration and Key Enzyme Activities of Avocado Peel

以褐、红、黄3种不同果皮色泽的油梨果实为试材,研究其采后不同转色期果皮叶绿素、花青素、类胡萝卜素等主要色素物质含量与关键酶活性的动态变化规律及其相关性,以期探明该3种油梨果皮呈现不同色泽的生理原因。结果表明:(1)该3种果实果皮着色过程中均可测出叶绿素、花青素和类胡萝卜素。其中,红皮、褐皮油梨果皮花青素含量均随着果实转色进程而显著提升,红皮油梨着色高峰期果皮叶绿素与类胡萝卜素含量显著下降,褐皮油梨果皮叶绿素与类胡萝卜素含量在整个着色期间均无显著变化。黄皮油梨果皮叶绿素与类胡萝卜素含量均在转色高峰期显著下降,花青素含量则无显著变化。(2)红皮油梨与褐皮油梨的各个关键酶活性变化趋势相似,CHS的活性显著上升,ANS显著下降,F3H无显著变化,UFGT先下降后升高,黄皮油梨CHS的活性无显著变化,ANS先下降后升高,F3H显著升高,UFGT显著下降。(3)ANS、F3H活性与3种油梨果皮花青素含量均呈负相关,与CHS活性则均呈正相关。UFGT活性与红皮、黄皮油梨果皮花青素呈正相关,与褐皮油梨花青素含量则呈负相关。由此可见,成熟期油梨果皮所呈现的颜色是由叶绿素、类胡萝卜素与花青素等色素物质共同作用的结果,其中花青素是红皮、褐皮油梨着色的主要物质,叶绿素与类胡萝卜素的降解则与油梨果皮呈现黄色密切相关。

In order to explore the physiological reasons for the different color of three kinds of avocado fruits,the contents of chlorophyll,anthocyanin,carotenoid and other major pigment substances and the activities of key enzymes were studied by using three kinds of avocado fruits with different color of brown,red and yellow skin as test materials.The results showed that:(1)chlorophyll,anthocyanin and carotenoid could be measured in the pigmentation process of the three fruits.Among them,anthocyanin contents of red and brown avocado skin increased significantly with the process of fruit color transformation,chlorophyll and carotenoid contents of red avocado skin decreased significantly at the peak of pigmentation,and chlorophyll and carotenoid contents of brown avocado skin did not change significantly during the whole pigmentation period.The contents of chlorophyll and carotenoid decreased significantly at the peak of color transformation,while the contents of anthocyanin had no significant change.(2)The activity trends of various key enzymes in red and brown avocado were similar:CHS activity increased significantly,ANS decreased significantly,F3H did not change significantly,and UFGT decreased first and then increased;CHS activity in yellow avocado did not change significantly,ANS decreased first and then increased,F3H increased and UFGT decreased significantly.(3)The activities of ANS and F3H were negatively correlated with anthocyanin content,while CHS activity was positively correlated.UFGT activity was positively correlated with anthocyanin content in red and yellow skin,but negatively correlated with anthocyanin content in brown skin.In conclusion,the color of avocado skin at maturity stage is the result of the interaction of chlorophyll,carotenoid and anthocyanin,among which anthocyanin is the main substance for the color of red and brown avocado,and the degradation of chlorophyll and carotenoid is closely related to the yellow color of avocado skin.