Total Antioxidant Capacity and Polyphenol Concentration of Several Pharmaceutical Integrators and Food or Feed Based Vegetables, Measured and Compared Using Two Different Enzyme Sensors

Background: This research had two purposes: first to verify if two enzyme biosensors developed by our research group for determining the Total antioxidant capacity (TAOC) and to determine the total polyphenol concentration (TPC) could correctly be used even in matrices such as commercial pharmaceutical supplements, as well as, earlier, have been used to analyze vegetables or food and feed based vegetables, only. The second was to determine whether there is a correlation between the values of TAOC and TPC, so measured, both in pharmaceutical supplements, analyzed in this work, and in several vegetables and food or feed based vegetables, analyzed with the same biosensors, but in our previous works. Methods: The two used amperometric biosensors are based on a Clark type electrode and on the enzyme superoxide dismutase, that for the measurement of the TAOC and on the tyrosinase enzyme, the one for the measurement of the TPC. Results: The results obtained showed that the first of these targets set has been largely achieved: TAOC and TPC can be effectively measured, with rapid biosensing methods, simple and also cheaper, in pharmaceutical supplements. The second objective showed that the correlation between TAOC and TPC certainly exists in vegetables and their derivatives, where the antioxidants consist essentially of polyphenols, while, in the pharmaceutical suppliers this correlation has been verified only in those commercial products based almost exclusively on vegetable products, while this correlation does not exist in more complex products, which contain molecules which of course have antioxidant compounds, but of kind also very different from those based only on vegetable antioxidants. Conclusion: The two enzymatic sensors have proven reliable and analytically suitable, also for applications in real matrices and the determination of total polyphenol concentration (TPC) can be considered a good indicator of the total antioxidant capacity (TAOC) and also but not always in pharmaceutical supplements.