Improved differentiation of carbohydrate pools using a multiphasic model to describe gas production from cell wall and cell content fractions compared with that from the whole food

Abstract

Whilst it is recognized that most foods contain a number of different carbohydrate pools most applications of the gas production technique do not allow them to be differentiated despite their likely different nutritional attributes. Schofield and Pell (1995) reported that improved fermentation kinetics of the carbohydrate pools could be obtained by making gas production measurements on the whole food and on its neutral-detergent fibre (NDF) fraction, the data on the neutral-detergent solubles (NDS) being calculated by difference. More recently Doane et al. (1996) proposed an expansion of this to include incubation of the ethanol insoluble residue, to enable the NDS fraction of the food to be separated into a soluble carbohydrate and organic acids fraction and a starch and pectin fraction. Another approach is that of Groot et al. (1996) who used a multiphasic model of whole food gas production to show that the gas is produced from more than one food fraction. The objective of the present work was to combine these two approaches to examine the value of the multiphasic model applied to gas production from the isolated NDF and NDS fractions.