Analytical determination of antioxidants in tomato:: Typical components of the Mediterranean diet

Diets in the countries of the Mediterranean basin are characterised by abundant plant foods (fruits, vegetables, breads, nuts, seeds, wine, and olive oil) and include fish and low-fat dairy products. Among the vegetables, tomatoes are a main component of the traditional Mediterranean diet, which has been associated with health protection and longevity. Eating tomatoes has been associated with reduced risks of some types of cancer and other diseases. These beneficial properties appear to be related to the antioxidant content of the fruit, particularly carotenoids (lycopene and beta-carotene), ascorbic acid, and phenols, which may play a role in inhibiting reactions mediated by reactive oxygen species. Due to the importance of antioxidant compounds in tomatoes and tomato products, we present here an overview of current analytical methods (from 2000 until the present date) for determining the different antioxidants. The analytical procedures used to determine individual compounds involve extraction from the sample, analytical separation, and quantification. The choice of analytical method depends on the particular focus of the analysis and the kind of product analysed. High-performance liquid chromatography is the technique of choice for the analysis of tomato antioxidants.