Factors influencing the post-harvest quality and consumer preference of sweet potato and other products in sub-Saharan Africa

The first theme covers sweetpotato in the marketing chain from farm to consumer. In East Africa, research explored ways of improving the handling and transport of sweetpotato, shelf life and storage of fresh roots on the farms to increase incomes and food security. Transport and handling were investigated using a novel ‘electronic sweet potato’ where it was found that it was the large number of minor vibrational type impacts that cause the most root damage. Reducing the sack weight and using fibreboard boxes reduced damage. A shelf-life investigation into the types of injury occurring through poor handling suggested that skinning injury, followed by broken roots caused the greatest shelf-life losses. The second theme explores sensory evaluation and consumer preference of sweetpotato and other food commodities. Research explored the variability of sensory parameters and acceptability of sweet potato cultivars with location and season in Tanzania and developed a model for predicting the acceptability of new cultivars derived from breeding programmes. The approach was extended to the acceptance of biofortified sweetpotato containing s-carotene differences in acceptance between locations and ethnic groups for rice and cassava products, variations in roasting conditions and shelf-life of peanut butter, and relationships between acceptability, market price and affordability of rice. Over 1,800 consumers were interviewed. This research suggests consumers in rural and urban Africa tend to be open to new products and this is contrary to views often held. Consumer acceptance was found to be ‘multi-modal’ with distinct variations within populations. Consumers in these different segments also had distinct socio-economic populations. Acceptability differed for rice and cassava products with respect to location, gender and age but not within ethnic group.