Recent advances in stable isotope techniques for the determination of geographical origin of plant-based foods

Authenticating the geographical origin of plant-based foods plays a critical role in enhancing consumer confidence, preventing food fraud, and resolving trade disputes. Stable isotope analysis, encompassing both light (H, C, N, O, S) and heavy (Sr, Pb) isotopes, has been widely regarded as a reliable tool for origin verification because isotopic signatures reflect environmental, climatic, and geological conditions. However, despite its broad acceptance, the technique faces ongoing challenges related to methodological variability, limited reference datasets, and uncertainties in interpreting multivariate isotopic patterns. This review critically evaluates the theoretical foundations, analytical strategies, and major isotopic systems employed in origin authentication, highlighting not only their strengths but also their current constraints. Recent methodological advancements are discussed, including the application of machine learning (ML), improved standardization of reference materials, and the expansion of target plant-based food categories. Representative case studies are used to demonstrate both the potential and the persistent shortcomings of isotope-based traceability. Overall, this review underscores the increasing utility of isotopic approaches while emphasizing the need for more rigorous validation, harmonized protocols, and integrative data frameworks to ensure robust and reproducible provenance determinations. • Stable isotope analysis provides a validated framework for food provenance studies. • The combined use of multi-isotopes and trace elements is highly effective for origin determination. • Methodological advances include ML/DL integration, & multi-element coupling. • Applications encompass processed foods, enhancing authenticity and traceability.