| Research Abstract |
We studied the impact of heating on Al ion binding amount of IDF (insoluble dietary fiber) and SDF (soluble dietary fiber) fraction extracted by the modified Prosky methed from 14 kinds of food after different heat treatments. In order to examine each of the fractionated sugars, ion exchange chromatography with DEAE cellulose was employed. Aloe fractions were further subjected to gel chromatography in order to examine the effect of heating on molecular weight.
As a result the following facts could be disclosed. The SDF fractions of anhydrous samples of okra, cabbage, celery, bitter gourd, and carrot were large when autoclaved, while that of aloe was largest when unheated, and those of eggplant, edible burdock,Japanese radish, hijiki, and nameko were large when microwaved. The SDF fractions of moroheiya and okra includes acid polysaccharides in large quantities, and acid polysaccharides increased further with autoclaving. The SDF fraction of celery did not
show as pronounced a tendency for heat-induced increase of acid sugar. Al binding of unheated IDF was high in edible burdock, carrot, cabbage, and hijiki. Heating- marginally raised Al binding amount of aloe and okra, but the other samples showed a tendency of Al binding amount to fall by heating. Al binding of unheated SDF was extremely high in aloe, which has a high mucilage content, followed by okra, while eggplant, celery, cabbage, common mushroom, edible burdock, carrot and moroheiya also had high values. Whereas non-mucilaginous foods had lower binding capacities when heated, such viscous foods as aloe, okra, and moroheiya increased their binding capacities by microwaving, IR analysis confirmed that heating affected the functional groups of SDF fraction.
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