From discard to resource: unlocking the environmental and nutritional value of Bambara groundnut waste

Abstract

Introduction: Global food security is under increasing threat from population growth, environmental degradation, and climate change, highlighting the need for resilient and nutrient-rich alternative crops like Bambara groundnut. Native to sub-Saharan Africa, this underutilized legume boasts drought tolerance and nitrogen-fixing properties, making it a valuable asset for food and nutrition security. However, the processing of Bambara groundnut generates substantial waste, contributing to environmental harm, greenhouse gas emissions, and resource wastage. Current disposal methods, such as landfilling and open burning, worsen climate change and pose significant health risks to local communities. Methods: This systematic review followed PRISMA guidelines, searching Google Scholar, Web of Science, PubMed, and Scopus (May-June 2025) for studies on Bambara groundnut waste valorization. The review identified integrated valorization pathways, challenges, and relevant case studies, providing a comprehensive analysis of Bambara groundnut waste potential. Results: The review found that key pathways for valorization offer a number of benefits. Bioenergy production offers clean energy and reduces fossil fuel reliance. Soil amendments improve soil fertility, structure, and water retention, reducing the need for synthetic fertilizers while sequestering carbon. Bio-based materials mitigate plastic pollution and address water quality challenges. Furthermore, nutrient extraction yields dietary fiber, proteins, and bioactive compounds for food and animal feed enrichment, enhancing nutritional security and maximizing resource utilization. Case studies on legume wastes demonstrate potential for environmental, nutritional, and economic benefits. Discussion: Widespread adoption of valorization initiatives faces multiple challenges, including technical, economic, regulatory, and socio-cultural barriers. Overcoming these necessitates collaborative efforts encompassing supportive policy measures, dedicated research, strong stakeholder partnerships, and effective community education. Through the valorization of Bambara groundnut waste, the agricultural sector of Africa can realize opportunities for sustainable development, enhanced food systems, and economic empowerment.