The digestible carbohydrate and dietary fibre contents of common sri lankan plant foodstuffs

Abstract

The dietary fibre and digestible carbohydrate contents of over 50 typically Sri Lankan plant food sources is reported. Digestible carbohydrate was determined by specifically hydrolysing carbohydrate enzymatically (heat stable α- amylase, amyloglucosidase and invertase) followed by determining reducing sugar formed colorimetrically. As expected, this gives lower values than carbohydrate determined "by difference" as reported by the food composition tables of the region. This in turn lowers the true energy value of the food. The over-estimation was maximum (5-12 fold) in case of leafy vegetables and minimum in case of starchy tubers(<1.15 fold) and cereals and pulses(<1.2 fold). The digestible carbohydrate values were over-estimated by 1.5 fold in case of non-starchy tubers and fruits. In the case of fruit vegetables the variation in over-estimation was high. (1-5 fold). Dietary fibre has been quantified using an enzymic digestion process of Asp and co-workers followed by gravimetry. This has resulted in the determination of both soluble and insoluble dietary fibre which would be vitally important to nutritionists, physicians and the public, if incorporated into Sri Lankan food composition tables.