Comparative study of phenolic fraction in olive fruits (Olea europea L.) during oil accumulation in three different Italian varieties: Frantoio, Favolosa and Don Carlo

The intra-species cross breeding program carried out by ISAFOM CNR from 1970 brought to patented of two new olive varieties originated by cv Frantoio, an Italian traditional variety characterized by high vigour, self-unfertility, medium productivity and high sensitive to low temperatures: the first, named “Favolosa” [Patent CNR-IRO n°1165/nv], resulted by a mass selection within a seedling population from free pollination of the cv Frantoio, is characterized by self-fertility, high rooting attitude, high productivity, low vigour and is particularly suitable for high density olive groves [Fontanazza et al., 1998]; the last one named “Don Carlo” [Patent CNR-IRO n° RM99NV000020] is the results of a mass selection within a seedling population coming from self-pollination of "Frantoio" and it is characterized by medium vigour, self fertility, high rooting attitude, high productivity and good resistance to low temperatures. Today, Favolosa and Don Carlo are diffused in Italy and especially in the new extra-Mediterranean areas of diffusion of olive grove (Australia, New Zeland, Cile, Argentina, South Africa, and USA) where the integral mechanization of the olive orchards needs low vigour varieties [Fontanazza et al., 1998].The worldwide spreading of these new varieties brought to a close study of their oil especially with regard to phenolic composition. In fact these compounds contribute to both organoleptic properties and oxidative stability of virgin olive oils and are associated with health benefits. The main classes of phenols in olive fruit and in virgin olive oil are phenyl ethyl alcohols, phenolic acids, flavonoids and secoiridoids. Recently lignans, an other class of phenolic compounds were found in virgin olive oil. The qualitative and quantitative composition of phenolic compound in olive oil depends on genetic factors, ripening stage of olives agronomic conditions of production and extraction conditions, especially crushing and malaxation phases. Actually, phenolic compounds have been studied prevalently in virgin olive oil; on the contrary few studies concerning the phenolic compounds in olive fruit were carried out.