不同溶质型桃果实成熟过程中酚类代谢与抗氧化能力的研究

以不同溶质型桃果实"加纳岩"和"雨花三号"为试材,测定两个品种桃果实在树体成熟过程中的多酚含量、类黄酮含量以及苯丙氨酸解氨酶(phenylalanin ammonialyase,PAL)、过氧化物酶(peroxidase,POD)、多酚氧化酶(polyphenol oxidase,PPO)活性变化,并采用1,1-二苯基-2-三硝基苯肼(DPPH)法及2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)法对其抗氧化能力进行评价。结果表明:"加纳岩"桃果实的多酚含量和类黄酮含量在成熟过程中均显著高于"雨花三号"桃果实;软溶质型"雨花三号"桃PPO活力高于硬溶质型"加纳岩"桃,但前者POD及PAL活力低于后者,其中"加纳岩"桃PAL活力初期高,成熟过程中与多酚含量呈正相关,"雨花三号"桃PAL活力呈上升趋势,与多酚含量无显著相关性;DPPH法和ABTS法均表明"加纳岩"桃抗氧化能力高于"雨花三号"桃。

Study of Phenolic Metabolism and Antioxidant Activities of Two Peach Cultivars during Maturation

The peach (Prunus persica) cultivars, Jianayan and Yuhua 3 were used in determining the changes in the total phenol and flavonoid content, and the activities of phenylalanine ammonia lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) in the process of fruit ripening, and evaluating the antioxidant capacity of the peach fruits by DPPH and ABTS assays. The total phenol content and flavonoid content of Jianayan were significantly higher than those of Yuhua 3 during the maturation process. PPO activity in the melting-flesh Yuhua 3 peach fruits was higher than that in the non-melting-flesh Jianayan peach fruits; however, the activities of POD and PAL in Yuhua 3 were lower than those in Jianayan. PAL activity in Jianayan was high at the beginning of the maturation process, and there was a positive correlation with polyphenols. PAL activity in Yuhua 3 showed an increasing trend during the maturation process, and there is no significant correlation between PAL activity and polyphenol content; DPPH and ABTS assay methods showed that the antioxidant capacity of the Jianayan peach cultivar was higher than that of the Yuhua 3 peach cultivar.