Antioxidant Assay: A Comparison with Traditional Methods

Antioxidant activity of lactic acid bacteria is associated with multiple health-protective ef-fects. Traditional indexes of chemical antioxidant activities poorly reflect the antioxidant ef-fects of these bacteria in vivo. Cellular antioxidant activity (CAA) assay was used in this study to determine the antioxidant activity of cell-free supernatants (CFSs) of 10 Lactobacil-lus strains. The performance of the CAA assay was compared with that of four chemical an-tioxidant activity assays, namely, DPPH radical scavenging, hydroxyl radical scavenging (HRS), reducing power (RP), and inhibition of linoleic acid peroxidation (ILAP). Results of the CAA assay were associated with those of DPPH and ILAP assays, but not with those of RP and HRS assays. The inter- and intra-specific antioxidant activities of CFS were charac-terized by chemical and CAA assays. L. rhamnosusCCFM 1107 displayed a high antioxida-tive effect similar to positive control L. rhamnosus GG ATCC 53103 in all of the assays. The CAA assay is a potential method for the detection of antioxidant activities of lactobacilli CFSs