Dietary fiber content and composition of fruits in Taiwan

Forty-one fresh fruits frequently consumed in the Taiwan area were analysed for their dietary fiber content by an enzymatic-gravimetric method. Total dietary fiber (TDF) of these fruits ranged from 0.2 g (per 100 g edible weight) in grapes to 8.6 g in eggfruit. In citrus fruit, the proportion of soluble fiber in TDF was more than 50%. However, in some fruits like guavas and waxapple, soluble fiber took less than 30% of TDF. Soluble fiber in almost all fruit was comprised of a large amount of uronic acids, while the composition of insoluble non-cellulose polysaccharides (INCP) varied a great deal. Mangos and pummelos of different varieties were different in their sugar composition of INCP. Insoluble non-cellulose polysaccharides of a crisp type of persimmon had more arabinose and galactose, but those of soft persimmon contained mainly xylose. These results show that different types of fruit are distinct in their composition and hence, the properties of their dietary fiber. These data are useful for dietary assessments in Taiwan and South-East Asia.