Chemometric authentication of branded and crude spices using integrated GC–MS fingerprints and elemental profiling

Abstract

Counterfeit and substandard spice products present significant risks to food safety, nutritional quality, and consumer confidence. This study applied an integrated chemometric approach, GC--MS chemical profiling, and elemental analysis to authenticate and discriminate among crude, genuine-branded, and potentially adulterated spice products. Twenty spice samples from curry, ginger, turmeric, nutmeg, and thyme were analysed using gas chromatography--mass spectrometry (GC--MS) for volatile compounds, flame photometry for macroelements, and atomic absorption spectrometry (AAS) for microelements, respectively. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed clear separation between crude and branded spices. An optimized model framework using two principal components explained 70.55% of the total calibration variance (70.29% cross-validated variance). The hierarchical cluster analysis (HCA) dendrograms confirmed distinct clustering, highlighting close substitutability among certain spices based on their nutrient profiles. Elemental analysis indicated significant variation across samples: branded curry 3 and branded ginger 3 were rich in zinc and selenium, while branded nutmeg 1 exhibited exceptionally high iron content. Conversely, some branded products, such as branded curry powder, consistently showed low or absent levels of essential micronutrients. GC--MS profiling identified dominant fatty acids, including Octadec-9-enoic acid and Octadecanoic acid. These compositional differences underpin the discriminatory power of chemometric models, enabling reliable authentication of the crude and branded spices and the detection of potential adulteration. The study demonstrated that integrated chemical fingerprinting with multivariate analysis provides a robust framework for quality assurance and regulatory monitoring of commercial spice products.