Optimization of alcohol insoluble polysaccharides (AIPS) extraction from the Parkia speciosa pod using response surface methodology (RSM)

Central composite design (CCD) was employed to optimize the incubator temperature (X1X1: 60–90 °C), extraction time (X2X2: 1–3 h) and pH (X3X3: 3–6) to obtain a high alcohol insoluble polysaccharide (AIPS) yield with high uronic acid content and antioxidant property from Parkia speciosa pod. Analysis of variance (ANOVA) showed that the contribution of quadratic model was significant for the responses. Optimization study using response surface methodology (RSM) was performed and 3-D response surfaces were plotted from the mathematical model. The optimal conditions were: extraction temperature of 90 °C, extraction time of 2.8–3.0 h, and pH of 3.0. These optimum conditions yielded AIPS of ∼17–18%, uronic acid content of ∼97–99 mg/g and %DPPHsc of ∼48–50% and close agreement between experimental and predicted values was found.