Nuclear magnetic resonance metabolomics in Indigenous tropical fruits: emerging trends in bioactive compound discovery, monitoring, and functional food translation

The escalating global demand for natural, health-promoting foods has intensified scientific interest in indigenous tropical fruits as reservoirs of structurally diverse and biologically active phytochemicals. This review critically examines the application of nuclear magnetic resonance (NMR)-based metabolomics for the comprehensive profiling, structural elucidation, and quantitative monitoring of bioactive metabolites derived from indigenous tropical fruits. Beyond edible tissues, the valorisation of non-edible fractions (peels, seeds, rinds) is evaluated as a strategy to enhance phytochemical recovery, promote circular bioeconomy principles, and reduce agro-industrial waste. We delineate the analytical strengths of NMR spectroscopy within phytochemical and food metabolomics workflows, including its non-destructive nature, minimal sample preparation, intrinsic quantitative capability, high reproducibility, and superior structural resolution without reliance on external reference standards. The integration of NMR-based metabolomics with multivariate data analysis is discussed as a powerful platform for authenticity assessment, quality control, and bioactivity-guided screening. Collectively, this review positions NMR metabolomics as a robust, translational analytical framework for advancing indigenous tropical fruits from traditional commodities to scientifically validated functional ingredients, while supporting sustainable agricultural systems and environmental stewardship in tropical regions.