JOURNAL OF FOOD COMPOSITION AND ANALYSIS
Journal of Food Composition and Analysis 20 (2007) 337–345 www.elsevier.com/locate/jfca
Determination of antioxidant activity and antioxidant compounds in wild edible mushrooms
Mahfuz Elmastasa,Ã, Omer Isildaka, Ibrahim Turkekulb, Nuri Temura
Gaziosmanpasa University, Faculty of Science and Arts, Departmentof Chemistry, 60240 Tokat, Turkey b Gaziosmanpasa University, Faculty of Science and Arts, Department of Biology, 60240 Tokat, Turkey Received 13 July 2005; received in revised form 20 June 2006; accepted 3 July 2006
Abstract The methanolic extracts of dried Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda, Russula delica, Boletus badius, and Verpa conica were analyzedfor antioxidant activity in different systems including reducing power, free radical scavenging, superoxide anion radical scavenging, total antioxidant activity, and metal chelating activities. Those various antioxidant activities were compared to standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and a-tocopherol. The percentage inhibition methanolicextracts of dried Russula delica, Boletus badius, Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda and Verpa conica at 100 mg/mL concentrations on peroxidation in linoleic acid system were 99.7%, 99.2%, 98.8%, 98.4%, 98.3%, 97.9% and 97.7%, respectively, and greater than those 400 mg/mL of a-tocopherol, BHA and BHT (77%, 85%, and 97%). Among methanolic extracts from sevenwild edible mushrooms, the reducing power of Russula delica and Verpa conica were excellent, and were 1.32 and 1.22 at 200 mg/mL, respectively. Methanolic extract from Verpa conica, Boletus badius and Russula delica proved to be better at scavenging OÀd than other mushroom species. The scavenging effects of methanolic extracts from mushroom 2 species and standards on the DPPHd radical decreased inthe order of BHA4a-tocopherol4Lepista nuda4Russula delica4Polyporus squamosus4Pleurotus ostreatus4Agaricus bisporus4Verpa conica4Boletus badius and were, at the concentration of 180 mg/mL, 97.4, 95.4, 91.3, 86.1, 82.8, 81.3, 77.5, 75.7 and 68.7, respectively. The metal scavenging effect of extract of the mushroom species and standards decreased in the order of Verpa conica4Lepista nuda4Russuladelica4Boletus badius4Polyporus squamosus4BHT4Pleurotus ostreatus4Agaricus bisporus4BHA4a-tocopherol. On the other hand, total phenolic compounds, a-tocopherol, and b-carotene were determined in the methanolic extracts of dried Agaricus bisporus, Polyporus squamosus, Pleurotus ostreatus, Lepista nuda, Russula delica, Boletus badius, and Verpa conica. r 2006 Elsevier Inc. All rights reserved.
Keywords:Antioxidant activity; Antioxidant compound; Mushroom; Edible mushroom; Food safety
1. Introduction Free radicals are produced in normal and/or pathological cell metabolism. Oxidation is essential to many living organisms for the production of energy to fuel biological processes. However, the uncontrolled production of oxygen-derived free radicals is involved in the onset of many diseases suchas cancer, rheumatoid arthritis, cirrhosis and arteriosclerosis as well as in degenerative processes
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E-mail addresses: firstname.lastname@example.org (M. Elmastas), email@example.com (O. Isildak). 0889-1575/$ - see front matter r 2006 Elsevier Inc. All rights reserved. doi:10.1016/j.jfca.2006.07.003
associated with ageing. Exogenous chemical and endogenousmetabolic processes in the human body or in the food system might produce highly reactive free radicals, especially oxygen derived radicals, which are capable of oxidizing biomolecules, resulting in cell death and tissue damage (Halliwell and Gutteridge, 2003). Almost all organisms are well protected against free radical damage by oxidative enzymes such as superoxide dismutase (SOD) and catalase...