Neglected and underutilized crops in European food composition databases: Implications for nutrition, sustainability and biodiversity

Neglected and underutilized species (NUS) are increasingly recognized for their potential to contribute to sustainable diets, improved nutrition and resilient food systems. However, their integration into research, policy, and dietary assessment frameworks remains limited, due to inconsistent definitions of NUS, heterogeneous classification across data systems, and incomplete compositional information in food composition databases (FCDBs). The objective of this study is to critically examine the conceptual, nutritional and data-related dimensions of NUS with a particular focus on their representation in major FCDBs and the methodological challenges associated with harmonizing and interpreting heterogeneous data sources. Thirteen NUS were assessed using a semi-quantitative coverage mapping approach across major publicly available FCDBs and selected national databases. NUS showed variable representation across FCDBs, with generally moderate coverage for macronutrients and selected micronutrients, but limited or missing data for bioactive compounds, fatty acids and cultivar-level variation. Several species were absent or poorly represented across databases. The findings highlighted significant gaps in the representation of NUS in FCDBs and the need for improved data harmonization and structured metadata systems that integrate nutritional, biodiversity and environmental dimensions. Strengthening database interoperability and species-level resolution is essential for accurately assessing the contribution of NUS to sustainable and nutritious food systems.