Changes of soluble protein,SOD,POD and CAT activities in orange(Citrus sinensis Osbeck) during summer fruit storage

Studies were carried out on the changes of nutrient materials?熏 soluble protein?熏 SOD?熏 POD and CAT activities in Orange (Citrus sinensis Osbeck) during fruit storage. The results showed that the changes of nutrient materials were that organic acid decreased remarkably. The content of soluble protein in peel was higher than it in flesh at the same period?熏 and the contents of soluble protein in two parts increased obviously during storage. The change curve of SOD activity was single peak. SOD activity increased at first and then decreased?熏 and the peak of SOD activity occurred in the 28th days after harvest. Changes of POD and CAT activities were different. POD activity in peel increased at first and then decreased, but POD activity in flesh tend to decrease. CAT activity in flesh was low during storage but it in peel increased remarkably at latter stage.