STUDY ON EXTRACTION AND DEGRADATION OF ELLAGITANNIN TO OBTAIN ELLAGIC ACID FROM WHITE POMEGRANATE PEEL (PUNICA GRANATUM L)

Abstract

White pomegranate variety with thick skin is popularly grown in many places
in Vietnam. Pomegranate peel contains many phenolic compounds and
ellagitannin. Ellagitannin are a group of tannin compounds that can be hydrolyzed
to produce natural ellagic acid. In this study, ellagitannin were extracted from white
pomegranate peels in Hoai Duc district, Hanoi city, using solvent ethanol 60%, at
80o
C for 3 hours. By hydrolyzing ellagitannin in 5% H2SO4 solution, at 105o
C for
5 hours, ellagic acid was obtained. Ellagic acid was purified by repeated
crystallization in methanol, at a ratio of 30ml methanol/1.0g crude ellagic acid. The
type of solvent and concentration of solvent used to extract ellagitannin,
concentration of H2SO4 acid solution and hydrolysis time of ellagitannin to obtain
ellagic acid with high yield were investigated and selected. The structure of ellagic
acid was examined by infrared and nuclear magnetic resonance spectroscopy data.
The content of ellagic acid was determined by high performance liquid
chromatography (HPLC) analysis. Research results have obtained 3.0g of ellagic acid
with 93.7% content from 100g of dried pomegranate peel powder.