橄榄多酚氧化酶和过氧化物酶的抑制剂筛选及其热失活动力学

Inhibitors of Polyphenol Oxidase and Peroxidase in Olive and Their Thermal Inactivation Kinetics

摘要:

本项目研究了七种抑制剂（分别为亚硫酸钠、明矾、O-异抗坏血酸、EDTA-2Na、CaCl2、多聚磷酸钠、柠檬酸亚锡二钠）对橄榄多酚氧化酶和过氧化物酶活力的影响,并采用两段模型分析了高温处理对橄榄果实多酚氧化酶(PPO)和过氧化物酶(POD)的钝化动力学。结果表明，橄榄中酚类化合物氧化分解与POD和PPO活性有关，在特定的环境条件下，O-异抗坏血酸和柠檬酸亚锡二钠抑制橄榄PPO酶和POD酶活性效果最好，譬如，其浓度为0.20 g/L时，可完全抑制橄榄PPO酶和POD酶活力；热烫时间和温度对橄榄果实PPO和POD活性影响较大，并随着热烫时间和热烫温度的增加，橄榄果实PPO和POD活性呈现先下降后处于平稳的趋势，故高温处理对橄榄PPO和POD的钝化过程符合两段模型。

Abstract:

The effects of seven inhibitors (sodium sulfite, alum, O-isoascorbic acid, EDTA-2Na, CaCl2, sodium polyphosphate and disodium citrate) on the activities of polyphenol oxidase and peroxidase in olive were examined in this study. The high-temperature deactivation kinetics of polyphenol oxidase (PPO) and peroxidase (POD) in olive fruits were analyzed using a two-stage model. The results showed that oxidative decomposition of phenolic compounds in Canarium album L. was associated with activities of POD and PPO. O-isoascorbic acid and disodium citrate disodium could the most powerful inhibitors against PPO and POD in olive under certain environmental conditions, e.g. at 0.20g/L, they could deactivate PPO and POD enzyme completely. The blanching time and temperature influenced greatly the activities of PPO and POD in olive fruits. The increase of blanching time and temperature led to an initial decrease in the activities of PPO and POD followed by a plateau. Therefore, the high-temperature deactivation process of PPO and POD in olive could be described using a two-stage model.