Tropentag, September 10 - 12, 2025, Bonn "Reconciling land system changes with planetary health"

Micronutrient density of neglected and underutilised African crops

¹Justus Liebig University Giessen, Agronomy and Crop Physiology, Germany
²University of Dschang, Faculty of Agriculture and Agricultural Sciences, Cameroon
³Ghent University, Laboratory of Functional Plant Biology, Dept. of Biology, Belgium
⁴Max-Planck-Institute of Molecular Plant Physiology, Germany
⁵International Institute of Tropical Agriculture (IITA), Nigeria
⁶International Institute of Tropical Agriculture (IITA), Benin
⁷Africa Rice Center (AfricaRice), Côte d'Ivoire
⁸The Alliance of Bioversity International & CIAT, Food Environment and Consumer Behaviour, Benin
⁹University of Abomey Calavi, Faculty of Agronomic Sciences, Benin
¹⁰The Alliance of Bioversity International & CIAT, Food Environment and Consumer Behaviour, Kenya
¹¹Africa Projects Development Centre, Nigeria

Abstract

The world's food security largely relies on a few highly developed major crop species, while many edible plant species remain neglected and underutilised. This trend can lead to one-sided and unbalanced diets. Within the project HealthyDiets4Africa, we aim to combat malnutrition in Africa by diversifying the entire food system. This includes analysing and promoting neglected and underutilised crop species, also called opportunity crops. To this end, we have compiled a list of 23 priority species from four different countries based on the following criteria: (i) perceived untapped potential in combating malnutrition; (ii) representation of fruits, seeds, leafy vegetables, and root crops; and (iii) limited information available in the scientific literature regarding nutritional values. Samples of these species were collected from farmers' fields or markets in Cameroon, Nigeria, Benin, and Côte d'Ivoire in 2023 and 2024 using a standardised protocol and documentation. The freeze-dried samples of the edible parts were subjected to nutrient analyses, focusing on protein, essential microelements such as zinc and iron, phytate, phenolics, and vitamins (especially B vitamins and vitamin C). Our initial results demonstrate the outstanding potential of some species to provide essential nutrients. Seeds of the leguminous tree species Parkia biglobosa (African locust bean) contain almost 35% protein. Leafy vegetables such as Basella alba (vine spinach) and Crassocephalum crepidioides (Fireweed) scored particularly high in terms of micronutrients like iron, zinc, and B vitamins. Fruits of Canarium schweinfurthii (African elemi) were particularly high in phenolics, indicating high antioxidative potential. However, we also observed substantial intra-species variation in nutrient concentrations, suggesting that factors such as variety and growing conditions, harvesting time and storage, can significantly affect the nutritional values of these plant foods. To harness the immense nutritional potential of these neglected and underutilised crop species, we need to target the entire food chain by developing growing systems, productive varieties, value chains, recipes, products, and consumer acceptance.

Keywords: Diversification, malnutrition, micronutrients, underutilised crops

Contact Address: Michael Frei, Justus Liebig University Giessen, Agronomy and Crop Physiology, Heinrich-Buff-Ring 26, 35392 Giessen, Germany, e-mail: michael.freiagrar.uni-giessen.de