1. Department of Chemistry and Chemical Technology, National University of Lesotho, Roma 180, Lesotho
2. Department of Biochemistry, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa
3. Department of Biotechnology and Food Technology, University of Johannesburg, Doornfontein Campus, P.O. Box 17011, Johannesburg 2028, South Africa
4. Department of Food Technology, University of Ibadan, Ibadan, Nigeria