Straightforward and rapid detection of C. canephora adulteration in roasted and ground Coffea arabica by near-infrared hyperspectral imaging and chemometrics.

Coffee is one of the most widely consumed beverages worldwide and plays a major role in global agricultural trade. Brazil is currently the world's largest producer and exporter of coffee. Two coffee species dominate the international market: Coffea arabica L. and Coffea canephora Pierre ex A. Froehner. Among them, Arabica is generally more highly valued in the specialty coffee market because of its more complex sensory profile and typically lower perceived bitterness. Consequently, the higher commercial value of Arabica creates favorable conditions for its adulteration with the less expensive Canephora coffee. To mitigate this type of food fraud, current Brazilian federal legislation requires the declaration and verification of the coffee species in commercial roasted and ground coffee products. However, regulatory agencies and the coffee industry still lack officially validated analytical methods to verify compliance with this requirement. Furthermore, conventional microscopy-based methods are challenged by the heterogeneous nature of roasted and ground coffee, making representative sampling difficult. To address this challenge, this study developed and validated a rapid, simple, and robust analytical method for detecting the adulteration of roasted and ground Arabica coffee with C. canephora at different roasting degrees. This was achieved by combining near-infrared hyperspectral imaging with chemometric analysis. The proposed method achieved an accuracy of 98%, specificity of 99%, and sensitivity of 93% for detecting adulteration levels greater than 5% (w/w), making it well suited for routine inspection and regulatory screening. Moreover, hyperspectral imaging enables the localization of suspicious particles for targeted confirmatory analysis, representing a practical and reliable approach for species authentication in roasted and ground coffee.