Qualitative and quantitative estimation of soluble indigestible polysaccharides as substrate for hindgut fermentation...

Pectin, guar gum, transgalactosylated oligosaccharide and glucose were estimated as substrate for hindgut fermentation by measuring the volume of gas released from a 1 ml scale batch culture using rat cecal contents. The amount of short-chain fatty acids (SCFA) in cultures of glucose and pectin was also measured. The amount of SCFA (Y mumol/culture) or volume of gas released (Y ml/culture) was expressed as an exponential function of incubation time (t) (Y = A+B x (1-e-kt); A, B and k are constants). The amount of potential production of gas and SCFA (B) for glucose was higher than that for pectin and the rate constant of gas and SCFA (k) for pectin was higher than that for glucose. The volume of gas released (ml/culture) correlated positively and linearly with the amount of total SCFA (acetic, propionic and n-butyric acids, mumol/culture). A single regression stood for both glucose and pectin. The gas release followed saturation kinetics. The half maximal concentration and maximal velocity for gas release from pectin were higher than those from other substrates (glucose, guar gum and transgalactosylated oligosaccharide).