Rapid and Eco-Friendly Quantification of Phenolic Compounds in Roselle Powder Using ATR-FTIR Coupled with Chemometric Modeling

Phenolic compounds are key contributors to the nutritional, functional, and commercial quality of roselle (Hibiscus sabdariffa L.) calyces; however, their routine quantification commonly relies on chromatographic methods that are time-consuming, solvent-intensive, and impractical for rapid quality control. This study aimed to develop a rapid and eco-friendly analytical approach for quantifying chlorogenic acid, caffeic acid, and rutin in roselle powder using attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy combined with chemometric modeling. Fifty samples representing different cultivars, drying methods, and geographical origins were analyzed. Elastic net classification achieved high accuracies for cultivar (96) and geographical origin (92), and moderate discrimination of drying methods (80). Quantitative prediction using partial least squares regression showed excellent performance for chlorogenic acid (R2P = 0.9108), while caffeic acid and rutin showed moderate predictive ability (R2P = 0.5357 and 0.6490, respectively). External validation yielded prediction deviations generally below 10. These results demonstrate that ATR-FTIR coupled with chemometrics provides a rapid, solvent-free, and reliable platform for phenolic profiling, with strong potential for sustainable quality control and process optimization in roselle-based food products. © 2026, Walailak University. All rights reserved.