Estimation of nutritional postharvest losses along food value chains: A case study of three key food security commodities in sub-Saharan Africa

Abstract

Postharvest losses (PHLs) amplify food insecurity and reduce the amount of nutrients available to vulnerable populations, especially in the world's Low and Middle Income Countries (LMICs). However, little is known about nutrient loss at the various postharvest stages. The objective of our study was to develop a methodology and a tool to estimate nutritional postharvest losses (NPHLs) along food value chains for three distinct food commodities in sub-Saharan Africa. The study used a combination of literature, laboratory and field data to investigate NPHLs caused by both changes in quantity and quality of food material (quantitative and qualitative NPHLs, respectively). The method can be expanded to various other food value chains. A user-friendly predictive tool was developed for case studies involving maize and cowpea in Zimbabwe, and for sweet potato in Uganda. Quantitative and qualitative NPHLs were combined and converted into predicted nutrient loss and nutritional requirement lost due to postharvest losses. The number of people who may not meet their daily nutritional needs, as a result of the food and nutrient losses at country level, was estimated. The estimates consider nutritionally vulnerable groups such as children under five years and pregnant women. The nutrient density of the harvested food material, the level of food production, the postharvest stages along the food value chain, the levels of pest damage along the value chain, and the susceptibility of the nutrients to degradation e.g. during storage, are all important factors that affect NPHLs. Our modelling work suggests that reducing PHLs along food value chains could significantly improve access to nutritious food for populations in LMICs.

The Fall Armyworm and Larger Grain Borer Pest Invasions in Africa: Drivers, Impacts and Implications for Food Systems

“…Human health is also affected by product contamination in storage, i.e., infestation by P. truncatus can increase the moisture content of the stored grains, inadvertently creating a favourable environment for fungal growth, e.g., Aspergillus flavus which can produce some carcinogenic aflatoxins in food products [ 193 ]. Furthermore, insect feeding also causes nutritional postharvest losses reducing basic access to nutritious food for consumers [ 17 , 215 ]. Cereal grains comprise 30–60% of the daily caloric intake for humans around the globe [ 216 ].…”

“…Increased global connectivity, anthropogenic climate change and a surge in the human population size have accelerated the rate of biological invasions with no indications of imminent saturation [ 1 , 12 , 13 , 14 ]. The SDG 12 emphasises improved and sustainable production (improved yields) reinforced by sustainable consumption and even sets specific targets related to the reduction of food loss and waste, including postharvest management [ 15 , 16 , 17 , 18 ].…”

Research and Technologies to Reduce Grain Postharvest Losses: A Review

“…Among the essential crop grains, cereals experience the highest proportion of postharvest losses [ 22 ]. Hence, postharvest intervention over the whole food supply chain reduces PHL.…”

“…Farooq et al [ 25 ] recently estimated that the global need for rice will persist upward, with projections indicating an increase from 479 million tonnes in 2014 to approximately 536–551 million tonnes by 2030, driven by anticipated population growth. Moreover, rice contributes to one-fifth of the global calorie supply [ 22 ].…”

Distribution, transportation, and coordination in African indigenous vegetables value chains: A scoping review

“…Post-harvest losses tend to amplify food and nutrition insecurity through both quantitative and qualitativei.e., nutritional losses. Reduction of PHLs can contribute to SDG 12.3, which aims to reduce food waste by 2030 by half, by reducing food losses along production and value chains (Bechoff et al, 2022;Jacob-John et al, 2022).…”