A Sustainable CE-DAD Screening Method for Multi-Class Polyphenol Profiling in Rosehip-Based Herbal Tea and Supplement

Rosehip-based products are rich in polyphenols with recognized health benefits, making accurate characterization essential for quality control and functional evaluation. Conventional analytical approaches for polyphenol determination are often time-consuming, costly, and environmentally demanding. In this study, a sustainable analytical method based on capillary zone electrophoresis coupled with diode array detection (CE-DAD) was developed as a green and accessible screening method for polyphenol analysis in rosehip-based products. Twelve polyphenolic compounds belonging to different classes (stilbenes, flavonols, flavanols, flavanones, and flavones) were used to optimize the electrophoretic conditions, including the buffer pH, voltage, and electrolyte concentration. Herbal tea and supplement samples were analyzed before and after a simple cartridge-based clean-up step to reduce matrix interferences. The method enabled simultaneous profiling of multiple polyphenol classes in a single CE-DAD run, showing excellent linearity (R² > 0.99), run to run reproducibility (RSD 0.8-1.6%), and sensitivity (LOD 0.4-1.4 μg/mL; LOQ 0.9-4.7 μg/mL). Eight target polyphenols were identified and quantified in real samples. Polyphenol profiling was complemented by DPPH and ABTS antioxidant assays, allowing a functional interpretation of compositional data and a case-based comparison between different product formulations. Specifically, the herbal tea showed the values of a 13.8 mg Trolox/g sample (80.5% DPPH inhibition) and 15.3 mg Trolox/g sample (98.5% ABTS inhibition), whereas the food supplement presented a 7.4 mg Trolox/g sample (34.2% DPPH inhibition) and 7.4 mg Trolox/g sample (54.1% ABTS inhibition). Method sustainability and applicability were also evaluated using the Blue Applicability Grade Index (BAGI), confirming a low environmental footprint.