1. Department of Rural Engineering, Faculty of Agronomy and Forestry Engineering, Eduardo Mondlane University, Maputo, Mozambique.
2. Soil and Crop Sciences Department, Cereal Quality Laboratory, Texas A&M University, College Station, TX.
3. Department of Food Science, University of Pretoria, Pretoria, South Africa.
4. Corresponding author. E-mail: jtaylor@postino.up.ac.za. Phone: +2712-420-4296. Fax: +2712-420-2839.