Effects of Irradiation and Heating on Extraction of Carbohydrates from Brown Seaweed, Gagome Kjellmaniella crassifolia

Changes in dissolved carbohydrates from Gagome Kjemaniella crassifolia by gamma-irradia-tion and boiling were investigated. When pulverized Gagome was irradiated in the dry state, solubilized carbohydrate levels did not change at dose levels up to 50 kGy; however, the molecular weights of main components in the soluble matter decreased. The amount of dis-solved carbohydrates increased with dosage increments of gamma rays when irradiated in water, and their molecular weights decreased markedly. When Gagome was irradiated with a dose of 10 kGy in the dry state, and then boiled in water, the amounts of carbohydrates dissolved were markedly high at 80°C during 10-h boiling in comparison with those of the non-irradiated control. On the other hand, at 100°C no difference was observed after 4-h boiling. There was no significant difference in the quantity of dissolved carbohydrates or their molecular weights between irradiated and non-irradiated samples heated at 120°C for up to 12 h. From these results dietary fibers in Gagome were found to be extracted and degradated by irradiation.