Authentication of Finger lime (Citrus australasica) cultivars enhances provenance in Australian native food supply chains

Traceability is critical to protect Australian Indigenous native foods, enabling market differentiation of high-value products. Finger lime ( Citrus australasica ) is a crop synonymous with this sector, yet cultivar-level identification remains a persistent industry issue. This study evaluated the application of portable near-infrared (NIR) spectroscopy combined with Soft Independent Modelling of Class Analogy (SIMCA) for the authentication of finger lime cultivars. The NIR spectra (950–1650 nm) were collected from whole fruit (n = 180) and analysed using SIMCA class models. Classification performance varied among cultivars where Rainforest Pearl, Byron Sunrise, Emerald, and Ricks Red achieved the highest classification accuracies (90–100%), while moderate to low accuracies were observed for Chartreuse, Red Champagne, Judy’s Everbearing, Red Centre Lime, and Sapphire. Lower classification in hybrids such as Red Centre Lime highlighted compositional variability as a challenge for classification. Overall, the study demonstrates that NIR spectroscopy, in combination with SIMCA modelling, provide a rapid, non-destructive, and cost-effective tool for finger lime authentication. This supports the Australian native food industry, which is dominated by small to medium enterprises, enabling real-time quality assurance, and market integrity. • Portable NIR (950–1650 nm) enables rapid, non-destructive analysis of finger limes • SIMCA models achieved high accuracy for several key cultivars (90–100%) • Hybrid cultivar (Red Centre Lime) showed reduced classification performance • Method supports traceability and provenance verification in native food supply chains • Provides a cost-effective authentication tool for small and medium enterprises