<i>In vitro</i> starch digestibility of by-products of sorghum starch extraction

Abstract

The aim of the present study was to assess the nutritive value of by-products of sorghum starch extraction, as dietary starch from feed grains. Five by-products differing in their particle sizes and starch contents were collected. The mean values of fraction yields and starch contents, for first, second and third fraction of sorghum gluten feed were respectively 16.13 – 52.63 %, 01.97 – 44.08 % and 04.99 – 56.75 %, while for sorghum gluten meal the values were 22.27 – 71.13 %. The substrates from whole grain meal, prepared by dry milling, and from by-products differed in their in vitro starch digestion. The mean values for kinetic parameters ranged from 0.0066 to 0.0147 min^-1 for the rate constant (k), from 53.66 to 98.58 % for the starch hydrolysis at infinite time (C_∞) and from 6.06×10³ to 8.47×10³ %.min for the area under the hydrolysis curve (AUC). Generally, a high digestibility of by-products of sorghum starch isolation with a great potential for sorghum in livestock and animal feeds are considered in this work.

Keywords: Sorghum, Starch extraction, By-products, Starch digestion, Animal feed