Not just colors—carotenoid degradation as a link between pigmentation and aroma in tomato and watermelon fruit

Several lines of evidence indicate that important fruit aroma volatiles are derived from the degradation of carotenoid pigments. One such compound, lycopene, the major pigment in the red varieties of tomato and watermelon, gives rise, to a number of aroma volatiles including geranial, a lemon-scented monoterpene aldehyde. Various tomato and watermelon varieties and transgenic and near-isogenic tomato lines that range in color from yellow through orange to pink and red differ markedly in their carotenoid profiles. These variations are accompanied by differences in the compositions of terpenoid volatiles and hence in their taste.