Optimization of Polyphenol Extraction Process from Yunnan-Grown Olives and Analysis of Taste Capacity Using Response Surface Methodology.

Abstract

This study aimed to optimise polyphenol extraction from Yunnan-grown olives (Canarium album), investigate key factors influencing taste capacity and their underlying mechanisms, and to provide technical support for industrial scale-up. Initial single-factor experiments assessed the effects of seven operational parameters on extraction yield and sensory quality. Subsequently, ethanol concentration, extraction temperature, extraction time, and pH were selected as independent variables to optimize the process and validate the model via a Central Composite Design (CCD), using total polyphenol extraction yield and taste capacity as response values. The results showed that single-factor experiments identified 60% ethanol as the optimal solvent, with enhanced extraction efficiency at a 3 h extraction time, a temperature of 50 °C, and a pH of 3. Quantitative analysis during single-factor experiments revealed strong correlations between extraction yield and taste capacity (r > 0.88). The response surface model exhibited a high goodness-of-fit; the impact of individual factors on the extraction yield followed the order of extraction temperature > extraction time > ethanol concentration > pH, whereas the order for taste capacity was extraction temperature > extraction time > pH > ethanol concentration. Under optimal process conditions, the total polyphenol extraction yield reached 216.38 ± 3.60 mg/g, with a taste capacity of 1.27 ± 0.02, showing no significant difference between the predicted and experimental values (p > 0.05). By synergistically regulating extraction parameters, the optimized process successfully balances efficient polyphenol dissolution with desirable taste characteristics. These findings provide a solid scientific reference for the value-added development of Yunnan-grown olive polyphenols.