Abstract
The object of this experiment is to illustrate the relation between the occurrence of chilling injury and the decrease of L-ascorbic acid (ASA) content in the seeds of stored sweet pepper fruit. We determined the changes of ASA and phenols content during development of chilling injury and the changes of some enzyme′s activities concerning with phenol formation and oxidation of ASA.
1. The ASA content in sweet pepper seeds decreased remarkably during storage at 1°C. And the reducing substances (cysteine, glutathione (reduced form), and NAD(P)H) except ASA were slightly increased during storage at 1°C.
2. The total phenols and O-diphenols content, to form brown pigment, in sweet pepper seeds increased on the second day and then decreased during storage at 1°C.
3. The glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities were high during storage at 1°C rather than at 20°C. The shikimate dehydrogenase activity increased remarkably until the fourth day when the symptom of chilling injury was observed, in seeds during storage at 1°C. The polyphenoloxidase activity increased gradually during storage at 1°C and 20°C with almost no difference between the activities at both temperatures.
4. The ascorbate oxidase and peroxidase activities during storage were lower at 1°C than at 20°C. The catalase activity showed little change during storage at 1°C.
