The current interest in replacing synthetic food additives by others of natural origin, together with toxicological results concerning the safety of antioxidants obtained by chemical synthesis, have boosted the search for alternative sources of antioxidants and new manufacturing methods. A number of studies have been reported on the importance of natural antioxidants in food and biological systems. In foods, antixidants protect against the oxidative deterioration of fats and oils owing to their ability to scavenge free radicals and oxygen, to chelate metals or act as reducing agents. At the biological level, although antioxidants are not essential from a nutritional point of view, they may increase the endogenous defenses and protect against cancer, aging and chronic and degenerative diseases.
    Many active antioxidants of phenolic structure are present in vegetal biomass as defense mechanism against radiation and infections. Vegetables, cereals, medicinal plants, and algae are traditional sources of these compounds, but the alternative sources are under consideration. Due to the protective character of phenolic compounds, most of them are distributed in the outer parts of vegetables, which in many cases correspond to agricultural and industrial wastes. Antioxidants are also present in waste liquid effluents from vegetable processing, in a way that if these streams are used as antioxidant sources, a double goal (economic and environmental) can be reached.
    Environmentally friendly processes have been developed for the extraction, concentration and purification of compounds with antioxidant properties from several wastes and underexploited materials.

    The responsible scientists for the work related to the production and evaluation of antioxidants are Prof. Herminia Domínguez and Dr. Andrés Moure.

    Two R&D projects are going in this line, funded by the Ministry of Science and Innovation of the Spanish Government, and by Xunta of Galicia (Galician Government), as well as two R&D contracts with industrial partners.