Evaluating the ability to enrich the polyphenol content in the lotus seed epicarp extract by macroporous resin

Abstract

The lotus seed epicarp is a byproduct of lotus seed processing, mostly discarded or dried for use as fuel. Polyphenols, a group of compounds with antioxidant properties that protect cells from damage caused by free radicals, have been found in the lotus seed epicarp. An effective enrichment method is required to enhance the total polyphenol content in lotus seed epicarp extract while utilizing natural medicinal resources for disease prevention. Currently, macroporous resins have been much concerned due to their potential applications in the adsorption, isolation and purification of bioactive compounds such as phenolics, alkaloids, flavonoids, tannins, and saponins from plant extracts. With a simple implementation and operation process, low cost, avoidance of toxic solvents, and the ability to be reused, the enrichment of polyphenols using macroporous resins is considered a feasible and promising approach. This study evaluates several factors affecting the polyphenol enrichment process using macroporous resin. The results show that HPD 750 resin exhibits good adsorption and desorption capacities, with values of 18.96  0.16 mg/g and 68.56  1.28 %, respectively, under the following conditions: extract concentration of 5,000 ppm, adsorption time of 30 minutes, desorption solvent of 96% ethanol, and desorption time of 180 minutes. The polyphenol content in the extract before and after enrichment was determined to be 363.89  6.27 and 517.48  4.73 mg GAE/g. From these results, it can be concluded that the polyphenol enrichment method using macroporous resin is effective.