Table of Contents
Advances in Pharmaceutics
Volume 2014, Article ID 262807, 8 pages
http://dx.doi.org/10.1155/2014/262807
Research Article

Evaluating the Effect of Gamma Radiation on the Total Phenolic Content, Flavonoids, and Antioxidant Activity of Dried Pleurotus ostreatus ((Jacq. ex. Fr) Kummer) Stored in Packaging Materials

1Graduate School of Nuclear and Allied Sciences, Department of Nuclear Agriculture and Radiation Processing, P.O. Box LG 80, Legon, Ghana
2Department of Botany, University of Ghana, P.O. Box LG 55, Legon, Ghana
3CSIR-Food Research Institute, P.O. Box M20, Accra, Ghana
4Applied Radiation Biology Centre, Ghana Atomic Energy Commission, P.O. Box AE 1, Atomic, Accra, Ghana
5Radiation Technology Centre, Ghana Atomic Energy Commission, P.O. Box AE 1, Atomic, Accra, Ghana

Received 30 April 2014; Revised 22 July 2014; Accepted 31 July 2014; Published 24 August 2014

Academic Editor: Maria Cristina Bonferoni

Copyright © 2014 Nii Korley Kortei et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Dried Pleurotus ostreatus mushrooms stored in polythene and polypropylene packs were exposed to gamma radiation from a cobalt-60 source at doses of 0, 0.5, 1, 1.5, and 2 kGy at a dose rate of 1.7 kGy/hr and stored for a period of 1 month. Total phenolic contents, flavonoids, and free radical scavenging activity DPPH (2,2′-diphenyl-1-picrylhydrazyl) were determined using aqueous, ethanol, and methanol extracts by Folin-Ciocaultaeu method as a source of potential natural antioxidants. Total phenol content ranged 0.56 ± 0.01–10.96 ± 1.7 mg/GAE, flavonoids ranged 1.64 ± 0.05–8.92 ± 0.6 mg/QE, DPPH radical scavenging activity also ranged 7.02 ± 0.10–13.03 ± 0.04%, and IC50 values also ranged 0.08–0.16 mg/mL. Statistical differences (P < 0.05) were recorded for the extracts and the treatment doses of mushrooms stored in polythene and polypropylene packs. A significant linear correlation was confirmed between values for the total phenolic content and antioxidant activity of mushroom extracts. The high contents of phenolic compounds indicated that these compounds contribute to high antioxidant activity. Pleurotus ostreatus can be regarded as a promising candidate for natural mushroom sources of antioxidants with high value. The use of low dose gamma radiation by the local food industry could improve the hygienic quality, extend shelf-life, and preserve nutrients and antinutrients.