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An important field of research today is the control of ‘redox’ status with the properties of food and food components. Natural antioxidants present in the diet increase the resistance toward oxidative damages and they may have a substantial impact on human health. Dietary antioxidants such as ascorbates, tocopherols and carotenoids are well known and there is a surplus of publications related to their role in health. Plant phenols have not been completely studied because of the complexity of their chemical nature and the extended occurrence in plant materials. Extensively studied sources of natural antioxidants are fruits and vegetables, seeds, cereals, berries, wine, tea, onion bulbs, olive oil and aromatic plants. Attempts are also made to identify and evaluate antioxidants in agricultural by-products, ethnic and traditional products, herbal teas, cold pressed seed oils, exudates resins, hydrolysis products, not evaluated fruits and edible leaves and other raw materials rich in antioxidant phenols that have nutritional importance and/or the potential for applications in the promotion of health and prevention against damages caused by radicals. [Copyright &y& Elsevier]

The overall quality of virgin olive oil (VOO) is closely related to its oxidative stability that is usually evaluated through the stability index measured by the Rancimat apparatus. Quality characteristics and also pro-oxidant and antioxidant content for 52 Greek VOO samples (Koroneiki cv) were used to build up a model capable of predicting stability. Collinearity diagnostics, variable selection, and regression analysis were applied to the experimental data to locate the contribution of each parameter to the keeping quality of the samples. The predictive ability of the model was confirmed for a second VOO ample set of the same cultivar. It was found that except for the peroxide value, which negatively influences the stability, other important parameters were α-tocopherol, total polar phenol and total chlorophyll content. It is concluded that the colorimetric determination of total polar phenols, the spectrometric determination of total chlorophylls and the high-performance liquid chromatography analysis of α-tocopherol, not presently included in the established methods of official analysis, can be used for a better evaluation of VOO quality. These parameters, which can be easily adopted as routine methods by the industry, seem to be of utmost importance for shelf life prediction and expiration dating if applied for the promotion of the most competitive products in the international olive oil market. [ABSTRACT FROM AUTHOR]