Assisted ohmic heating extraction of pectin from pomegranate peel

Pomegranate peel is rich in various compounds such as pectin. The aim of this study was to first, find the optimal conditions for extracting pomegranate pectin by ohmic heating method and then, to compare the properties of this pectin with pectin extracted under optimal conditions by conventional acidic method. With conventional acidic method, the optimal extractor acid, pH and solid to solvent ratio were determined, they were hydrochloric acid, 1.5 and 1:40, respectively, and these results were generalized to ohmic heating extraction condition. Then, the effects of voltage gradient and time, during ohmic heating on the yield and galacturonic acid, were studied using the response surface methodology (RSM). According to the findings, the optimal conditions for the voltage gradient and time were 10 V/cm and 18 min, respectively. Extraction yield and galacturonic acid percentage were 8.16% and 82.86% in ohmic method and 8.93% and 73.84% in conventional method, respectively. As it can be seen, the galacturonic acid content of the pectin extracted under ohmic heating were significantly higher. The study on different pomegranate peel size showed that in ohmic heating even with bigger size of particle, the yield remained constant.

Automated summary

This study investigated the optimal conditions for extracting pomegranate pectin using the ohmic heating method, and compared its properties with pectin extracted using the conventional acidic method. The findings showed that ohmic heating extraction resulted in significantly higher galacturonic acid content in the pectin.