A Superoxide Dismutase Biosensor for Measuring the Antioxidant capacity of Blueberry Based Integrators

The antioxidant capacity of capsules containing blueberry based products which are included among the group of integrators owing to their antioxidant capacity and produced by various drug firms was investigated. The results of the investigation are compared to rank these products in order to their antioxidant capacity. In order to measure antioxidant capacity, our laboratory has recently developed a special electrochemical method based on a superoxide dismutase (SOD) biosensor to determine the superoxide radical. The results obtained by applying the SOD biosensor method to various blueberry based integrators were compared with the results obtained with the spectrophotometric (FRAP) method based on N,N-dimethyl-p-phenylenediamine (DMPD-FeCl3) and with those obtained also using the ORAC fluorimetric (TRAP) method. One of the more interesting aspects of the article is the good agreement it evidences of the results of the three methods for measuring antioxidant capacity. The three methods differ among themselves: an Electron Transfer (ET) method, a Hydrogen Atom Transfer Method (HAT) and an electrochemical based biosensor method of the Monitoring Superoxide Radical (MSR) type. It is also shown how the antioxidant capacity of the fresh vegetable is in any case always greater than that of any food supplement obtained from the same type of vegetable.