1. University of Kassel. Faculty of Organic Agriculture. Department of Agricultural & Bio- systems Engineering. Nordbahnhof str. 1a, 37213 Witzenhausen, Germany
2. University of Nairobi. College of Agriculture and Veterinary Sciences. Department of Food Science, Nutrition and Technology, P.O. Box 29053-00625, Nairobi, Kenya
3. School of Agriculture, Food and Rural Development, Newcastle University. Newcastle upon Tyne, NE1 7RU, United Kingdom