Determination of phenolic acids in pomegranate juices by HPLC- DAD

Abstract

In this study, five phenolic acids, gallic, chlorogenic, caffeic, p-coumaric and ferulic acid were determined in freshly squeezed pomegranate juice, commercial pomegranate juice and pomegranate juice concentrate beverages. For this purpose, an analytical method using high-performance liquid chromatography (HPLC), with a combination of photodiode array detection (DAD), was developed for the characterization and quantification of phenolic acid in pomegranate juices. Then the analyses of pomegranate juices were performed. The limit of detection (LOD, S/N=3) of individual compounds was gallic acid 0.1 mg/L, chlorogenic acid 0.01 mg/L, caffeic acid 0.03mg/L, p-coumaric acid 0.02 mg/L and ferulic acid 0.04 mg/L. The limit of quantitation (LOQ, S/N=10) of individual compounds was gallic acid 0.4 mg/L, chlorogenic acid 0.05 mg/L, caffeic acid 0.1 mg/L, p-coumaric acid 0.1 mg/L and ferulic acid 0.1 mg/L. The relative standard deviation (% RSD) in commercial pomegranate juice was found to be gallic acid 0.08%, chlorogenic acid 0.32%, caffeic acid 0.21%, p-coumaric acid 0.08% and ferulic acid 0.38%. The relative standard deviation (% RSD) in freshly squeezed pomegranate juice was found to be gallic acid 0.01%, chlorogenic acid 0.46%, caffeic acid 0.17%, p-coumaric acid 0.04% and ferulic acid 0.8%. The relative standard deviation (% RSD) in pomegranate concentrate juice was found to be gallic acid 0.78%, chlorogenic acid 0.25%, caffeic acid 0.49%, p-coumaric acid 0.36% and ferulic acid 0.17%.