Reassessing fatty acid divergence: climatic and geographic constraints on origin traceability in global oil crops.

Global agricultural trade requires reliable tools to trace product origins and combat fraud. We propose two novel metrics-the Geographical Differentiation Index (GDI) and Environmental Heritability Index (EHI)-to quantify spatial variation in fatty acids and their environmental drivers. We systematically investigated the fatty acid profiles of four main oil-rich crops (olive, camellia, walnut, and peony seed) and revealed that fatty acid distributions follow elevation- and latitude-dependent patterns, with peony seed oils showing the strongest latitudinal sensitivity. Key fatty acids like stearic acid (C18:0) and linoleic acid (C18:2) correlated significantly with geographic factors globally, while the biomass of certain specific fatty acids varies significantly in high-altitude/low-latitude regions. These findings establish specific fatty acid signatures as a robust tool for geographic authentication. Our approach provides a chemically grounded framework for precision origin discrimination in global oil food systems.