Plant Biotechnology to improve antioxidant capability

Vegetables are an important part of the human diet and a major source of biologically active substances such as vitamins, dietary fibres, antioxidants and other compounds. Despite a large amount of information on this topic, the nutritional quality of vegetables has not been defined in detail. By the turn of the century the application of innovative technology allowed quantitative and qualitative measurement of a large number of plant metabolites. Besides the importance for the plant itself, such metabolites determine the nutritional quality and health-promoting properties of food. The growing demand of food manufacturers and consumers of natural products with improved nutritional value exited research to develop innovative strategies to produce bio-fortified food. The improvement of nutritional quality of staple plant species through modification of endogenous metabolisms could be one of this approaches. Great interest was focused on phenylpropanoid pathway which has an important role along the plant kingdom. In particular, flavonoids and stilbenes have attracted much attention in relation to their antioxidant activity. In order to obtain fruit with higher antioxidant properties, the structural gene encoding a Vitis vinifera L. stilbene synthase was over-expressed in tomato plants. In resveratrol-producing fruits, an increase of soluble antioxidants as well as the total antioxidant activity was observed. These results could explain the higher capability of transgenic fruits to counteract the inflammatory process in animal cell system.