Deep eutectic solvents (DES) mediated extraction of pectin from Averrhoa bilimbi: Optimization and characterization studies.

The Box-Behnken design was applied to optimize the extraction of pectin from Averrhoa bilimbi (ABP) using deep eutectic solvents (DES). The four variables of extraction were percentage of DES (X₁), extraction time (X₂), temperature (X₃), and molar ratio of DES components (X₄). The quadratic regression equation was established as a predicted model with R² value of 0.9375. The optimal condition was X₁ = 3.74% (w/v), X₂ = 2.5 h, X₃ = 80 °C, and X₄ = 1:1. No significant difference between the predicted (14.70%) and experimental (14.44%) maximum yield of sample was noted. Characterization of physico-chemical properties characterization of ABP was performed. The main components of ABP were galacturonic acids, arabinoses, and xyloses. ABP also showed good functional properties such as water holding capacity (3.70 g/g), oil holding capacity (2.40 g/g), and foaming capacity (133.33%). The results also showed that ABP exhibited free radical scavenging activity (41.46%) and ferric reducing antioxidant power (1.15 mM).