Phenolic Acids Composition of Fruit Extracts of Ber (Ziziphus mauritiana L., var. Golo Lemai)

Abstract

Fruits of Ziziphus mauritiana L. (ber) are consumed in fresh and dried/processed form in many countries across Asia including Pakistan. In the present study, we analyzed the composition of total phenolic acids (free, soluble-bound and insoluble-bound) from ber fruit extracts by applying a pressurized liquid base hydrolysis extraction (PLBHE) using Dionium cells. Nine phenolic acids (protocatechuic, p-hydroxybenzoic, ferulic, chlorogenic, vanillic, caffeic, vanillin, o- and pcoumaric acids) were extracted, separated, and quantified by HPLC-DAD. Identification of phenolic acids was achieved by comparison of retention times, ultraviolet, and mass spectral data with authentic commercial standards. Results showed that p-coumaric acid (3719 ± 22 µg/g) was the predominant phenolic acid extracted from ber samples. In addition, four phenolic acids, namely p-hydroxybenzoic (2187 ± 71 µg/g), vanillin (2128 ± 20 µg/g), ferulic (2629 ± 96 µg/g), and o-coumaric acids (2569 ± 41 µg/g) were obtained in intermediate amounts from dried Ziziphus mauritiana L. fruit. The total phenolic acids content was determined as 18231 ± 306 µg/g dry matter basis (DMB). This study indicates that ber fruit is a good natural source of phenolic acids and that PLBHE can be used for the assay of phenolic acids.