Characterization of aqueous extracted pectin from pomegranate peel at optimized condition using response surface optimization

The research shows Box–Behnken experimental design coupled with response surface optimization a useful technique for aqueous extraction of pectin from waste pomegranate peel and visualize the effect that some experimental factors exert on several analytical responses. All experimental data obtained were analyzed by Design-Expert software version 7.0 and Microsoft Office Excel 2013. The obtained statistical results revealed that R 2 or the coefficient of determination was a statistical measure in a regression model provided an adequate fit to your data. The results showed that the optimal conditions for the maximum yield of pectin (9.91%) were achieved at time of 70.5 min, temperature = 89.8 °C, and liquid/solid of 20.3 mL/g. Degree of esterification of pomegranate peel extracted pectin was 31.18% demonstrating that pectin is classified as low-methoxyl and the results suggested a low Mw (1.693 kDa), high GalA content (about 65.9%). The finding showed the emulsifying activity was of 47.8% and water holding capacity and oil holding capacity were 3.8 g/g and 1.6 g/g, respectively. Pomegranate peel pectin also showed a viscosity of 23.7 mPa s in the concentration of 2% and a TPC of 17.92 mg GAE/g pectin with good antioxidant activity (IC50: 5.14 mg/mL). Gas chromatography analysis showed the major area of pectin consists of homogalacturonan (about 59.5%) also arabinan and arabinogalactan were the main side chains in rhamnogalacturonan-I. In final, structural characteristics of pectin were examined using FTIR, H-NMR and XRD analysis, and SEM was also used to study the surface properties.