Particle size-starch-protein digestibility relationships in cowpea (Vigna unguiculata)

作者：Tinus T; Damour M; van Riel V; Sopade P A^*

来源：Journal of Food Engineering, 2012, 113(2): 254-264.

DOI：10.1016/j.jfoodeng.2012.05.041

• pH drop method
• First-order kinetics
• Digestogram
• In vitro digestion
• Milling
• Diffusion coefficient

The kinetics of starch and protein digestion in hammer- and cryo-milled cowpea (70-370 mu m) were investigated. The pH during the protein digestion reduced with time, and both the starch and protein digestion exhibited monophasic digestograms, which were suitably (r(2) > 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 x 10(-7) cm(2) s(-1) as the diffusion coefficient. For the starch digestion, diffusion coefficients (cm(2) s(-1)) were 0.6 x 10(-7) (hammer-milled) and 0.3 x 10(-7) (cryo-milled). The protein digestion proceeded at a much faster (100x) rate than the starch digestion.

• 出版日期2012-11