Abstract
Potato tubers, sweet potato roots and carrot roots were irradiated with cobalt-60 gamma rays, and then cut into thin disks, which were incubated aerobically at 30°C under high humidity. The effects of gamma radiation on metabolic changes in the tissues in response to cutting were investigated. The polyphenol content in potato tissues increased as compared with the nonirradiated sample. However, the increase in polyphenol content in response to cutting was lower in the irradiated sample. In the case of sweet potato and carrot tissues, the in crease in polyphenol content in response to cutting was significantly stimulated in the irradiated sample. In sweet potato tissues irradiated with 90 krads, the increase in polyphenol content was correlated with the increase in phenylalanine ammonia-lyase. The effect of radiation on peroxictase development in sweet potato tissues was similar to that of polyphenol production. No significant effect on o-diphenol oxidase development was observed in sweet potato tissues. Even though gamma radiation stimulated the production of polyphenols and peroxidase development in sweet potato tissues in response to cutting, formation of lignin-like substance was inhibited by radiation.
