Chemical characterisation and in vitro assessment of the nutritive value of co-products yield from the corn wet-milling process

Abstract

The chemical characteristics of co-products recovered during a laboratory-scale wet milling procedure as well as that of whole corn flour were characterised and their digestibility and fermentability value determined using a 2 steps in vitro digestibility and fermentation model of the pig digestive tract. Five co-products differing in their chemical composition were collected and analysed. These co-products differed in their in vitro dry matter Digestibility and in their kinetic of fermentation. High coefficients of digestibility were observed for starchy samples, while low coefficients of digestibility were observed for samples rich in lignocellulosic components. Fermentation patterns of samples analysed were different as well as the profile of volatile fatty acids produced during the fermentation. The production of straight-chain fatty acids produced was significantly correlated with the proportion of starch in the sample, while branched-chain fatty acids were correlated to proteins concentration of samples.

Keywords: Corn; Digestion; Fermentation; Milling; Volatile fatty acids.