Deep eutectic solvent (DES)‐assisted extraction of pectin from Ficus carica Linn. peel: optimization, partial structure characterization, functional and antioxidant activities

Abstract BACKGROUND The pectin from Ficus carica Linn. (fig) peels is a valuable and recyclable constituent that may bring huge economic benefits. To maximize the utilization of this resource, deep eutectic solvent (DES)‐assisted extraction was applied to extract pectin from fig peels, and the extraction process was optimized with response surface methodology. RESULTS When DES (choline chloride/oxalic acid = 1:1) content was 168.1 g kg −1 , extraction temperature was 79.8 °C, liquid–solid ratio was 23.3 mL g −1 , and extraction time was 120 min, the maximum yield of 239.6 g kg −1 was obtained, which was almost twice the extraction of hot water. DES‐extracted fig peel pectin (D‐FP) exhibited better nature than hot water‐extracted fig peel pectin (W‐FP) in terms of uronic acid content, particle size distribution, and solubility, but lower molecular weight and esterification degree. D‐FP and W‐FP had similar infrared spectra and thermodynamic peaks but differed in monosaccharide compositions. D‐FP also showed good antioxidant capacities and exhibited better functional activities than W‐FP. CONCLUSION These results indicated that D‐FP was of promising quality being utilized in food or medical industries and the optimal DES‐assisted extraction method might be applied as a sustainable process for the effective extraction of bioactive pectin from fig peels with the excellence of low equipment requirements and simple operation. © 2024 Society of Chemical Industry.