Particle size-starch–protein digestibility relationships in cowpea (Vigna unguiculata)
2012
Tinus, T. | Damour, M. | van Riel, V. | Sopade, P.A.
The kinetics of starch and protein digestion in hammer- and cryo-milled cowpea (70–370μm) were investigated. The pH during the protein digestion reduced with time, and both the starch and protein digestion exhibited monophasic digestograms, which were suitably (r²>0.97, p<0.001) described by a modified first-order kinetic model. The in vitro protein digestibility of the cowpea (>80%) was independent of the milling conditions. The hammer-milled cowpea digested more, but the reciprocal of its rate of protein digestion was independent of the square of the particle size. The rate of protein digestion in the cryo-milled cowpea inversely depended (p<0.05) on the square of the particle size, with 67×10⁻⁷cm²s⁻¹ as the diffusion coefficient. For the starch digestion, diffusion coefficients (cm²s⁻¹) were 0.6×10⁻⁷ (hammer-milled) and 0.3×10⁻⁷ (cryo-milled). The protein digestion proceeded at a much faster (100×) rate than the starch digestion.
显示更多 [+] 显示较少 [-]