Increase of nutritional security in Sub-Saharan Africa through the production of dried products from underutilized crops

Abstract

Currently, an estimated 20% of the population in Sub-Saharan Africa is food insecure with the incidence of hunger and malnutrition still rising. This trend is amplified by the socio-economic consequences of the COVID-19 pandemic. In contrast, more than a third of the harvestable perishable produce is lost due to a lack of preservation or failure to utilize preservation as is the case for underutilized crops (UCs). Moreover, some of the preservation techniques utilized are poor, leading to the deterioration of food quality, especially the micronutrients. In this study, we thus exemplarily investigated the impact of different drying settings on the quality of two highly nutritious UCs, namely cocoyam and orange-flesh sweet potato (OFSP) (40, 60, and 80 °C for cocoyam and 40, 50, 60, and 70 °C for OFSP) to deduce the optimum quality retention and further develop a theoretical design of processing units and processing guidelines for decentralized food processing. Drying cocoyam at 80 °C and OFSP at 60 °C, respectively resulted in a relatively shorter drying time (135 and 210 min), a lower total color difference (2.29 and 11.49-13.92), greater retentions for total phenolics (0.43 mg GAE/100 gDM and 155.0-186.5 mg GAE/100 gDM), total flavonoid (128 mg catechin/100 gDM and 79.5-81.7 mg catechin/100 gDM) and total antioxidant activity (80.85% RSA and 322.58-334.67 mg AAE/100 gDM), respectively for cocoyam and OFSP. The β-carotene, ascorbic acid and vitamin A activity per 100 gDM of the OFSP flours ranged between 6.91- 9.53 mg, 25.90 − 35.72 mg, and 0.53 − 0.73 mg RAE, respectively.