1. Department of Food Science, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
2. Agricultural Research Council–Grain Crops Institute, Potchefstroom, 2520, South Africa.
3. Cereal Quality Laboratory, Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843.
4. Extraordinary professor, Department of Food Science, University of Pretoria.
5. Corresponding author. Phone: +27 124204296. E-mail: john.taylor@up.ac.za