DIGESTIBILITY OF DIETARY FIBER IN BROWN ALGA, KOMBU, BY RATS

Digestibility of the edible brown alga kombu was studied by feeding ra ts for 28 days. Food intake of both rats fed with basal and kombu diet s was statistically similar. Body weights of kombu groups were signifi cantly lighter, but their fecal weights were heavier, when compared wi th their counterparts with diets excluding kombu. There were no major differences in the weights of liver, pancreas, and kidney, but cecum, small intestine, and large intestine of rats fed with kombu were signi ficantly heavier than those without kombu. With the kombu diet, in the early feeding period protein digestibility was significantly lower th an in the control, but the digestibility of kombu groups recovered to the level of the control in the late feeding period. Fat digestibility in the kombu diet was significantly higher than that in the basal die t. Digestibility of insoluble and total dietary fibers in the kombu di et tended to increase in the feeding period. Alginate digestibility si gnificantly increased, and the molecular weight of alginate was down b y 60%. Since the molar ratio of mannuronic and guluronic acids in algi nate decreased significantly in the feeding period, mannuronic acid ma y he more decomposable in comparison with guluronic acid in rats.