foundational study on the stability limitations of catechin from uncaria gambier in aqueous systems: basis for industrial applications

This study is the first to report on the stability limitations of catechin from uncaria gambier in aqueous systems. catechin, a flavonoid in gambier extract, has limited commercial use, likely due to its color instability in aqueous formulations. this research examined catechin's stability in different solvent systems, focusing on water-based solutions. a 100 mg/l solution of high-purity catechin was prepared in pure water, 50% ethanol in water, and absolute ethanol. its purity was confirmed through liquid chromatography. stability was evaluated over eight days by measuring uv-vis absorption spectra (200-800 nm) and color changes using organoleptic observation. during the 8-day storage, catechin's maximum absorbance remained stable at 278–279 nm in all samples, but spectral shape changes were observed. in solutions containing water, an increasing absorbance in the 380-450 nm range was detected, correlating with brown discoloration. this suggests transformation affecting visual appearance. in contrast, catechin in absolute ethanol showed no spectral changes, indicating superior stability in non-aqueous conditions. these finding showed that catechin content remains stable in aqueous systems, but color changes limit its use in water-based products. this study identified a key challenge affecting the market potential of catechin-derived products and emphasizes the need for stabilization strategies in aqueous formulations.