Microwave assisted extraction of flavonoids from pomegranate peel and its antioxidant activity

Ju Huang,Weiping He,Xiaoqin Shi,Chen Yan,Xihua Du,J.Q Cheng,I Kim,J Zhang,H.L Moffitt,Z.T Chi

doi:10.1051/bioconf/20170803008

Abstract

Pomegranate peel, a waste generated from fruit processing industry, which contains maximum amounts of bioactive compounds than the juice, is a potential source of active ingredient such as flavonoids that are known for their antioxidant properties. Microwave-assisted extraction (MAE) of flavonoids from pomegranate peel and its antioxidant activity were investigated. Three independent and main variables, including ethanol concentration(%), solvent/solid ratio(mL/g) and MAE time(min), which were of significance for the yields of flavonoids were studied. The optimal conditions were determined by the orthogonal design. The maximum extraction yield of 4.260% was achieved at ethanol concentration of 60%, ratio of solvent to material of 40:1 and MAE time of 3min. In vitro antioxidant assays showed that the extract exhibited a strong DPPH radical-scavenging ability with IC50 value of 0.187 mg/mL. Results indicated that MAE was a suitable approach for the extraction of flavonoids from pomegranate peel.

Highlights

Pomegranate (Punica granatum L.) is a shrub or a small tree widely distributed in both tropical and subtropical areas
The results showed that the effect on the yield of total flavonoids was decreased in the following order when Microwaveassisted extraction (MAE) was used to extract total flavonoids from Pomegranate peels: ethanol concentration, the ratio of solvent to material and MAE time, that is A>B>C
DPPH free radical-scavenging of flavonoids from Pomegranate peels was less than that of VC, but the results indicated that flavonoids extracted by MAE had a strong DPPH radical-scavenging activity, with an IC50 value of 0.187 mg/mL

Summary

Introduction

Pomegranate (Punica granatum L.) is a shrub or a small tree widely distributed in both tropical and subtropical areas. It is an important source of bioactive compounds and has been used for folk medicine for many centuries [1]. Compared with the traditional methods, MAE has many advantages, such as higher extraction rate, shorter extraction time, use of less solvent, better productivity and higher quality products. It is a widely used technique for the extraction of valuable bioactive components from plant materials. The accelerated extraction may be attributed to synergistic action of temperature and concentration gradients [5,6,7]

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