A comparison of the antioxidant efficacy of beer and wine polyphenols

This study examines the antioxidant potential of beer compared to that of red and white wines. Beer and wine samples were tested using five different spectrophotometric assays for antioxidant potential: the Trolox Equivalent Antioxidant Capacity (TEAC) assay for total antioxidant activity, superoxide radical scavenging assay, hydroxyl radical scavenging assay, lipid peroxidation assay, and beta-carotene bleaching. Samples were diluted to equal ethanol content and tested on an "as-is" basis. The red wine sample was the most potent scavenger in the TEAC assay, the white wine sample outperformed all others in the superoxide scavenging assay as well as the hydroxyl scavenging assay. The beer samples proved superior in the beta-carotene bleaching assay. The lipid peroxidation assay was abandoned due to sample interference. The total polyphenol content of the samples was determined using American Society of Brewing Chemists (ASBC) Method Beer-35. The samples were diluted to equal polyphenol content and retested using the same assays. The white wine sample was the most potent scavenger in the TEAC assay and the superoxide scavenging. The beer samples again outperformed all others in the beta-carotene bleaching assay. The results of the equal polyphenols assay indicated that the hydroxyl scavenging assay was compromised by sample interference as well. The results of this study show that beer is a comparable source of dietary antioxidants when compared to red and white wines.