Changes in chloroplast pigments of olive varieties during fruit ripening

Changes in chlorophyll and carotenoid pigments of five olive (Olea europaea L.) varieties destined for milling were investigated at six consecutive ri pening stages. There was a manifest dependence between olive variety, momen t of picking, and chloroplast pigment composition of the fruits. Although t he content of chlorophylls and carotenoids differed with fruit variety, rip ening always involved their gradual loss, which becames more pronounced wit h increased presence of anthocyanin compounds. The relative rates of disapp earance of chlorophylls and carotenoids were markedly different between var ieties, implying that the catabolism of these pigments takes place at a rel ative rate inherent to each variety. The varieties less rich in pigments sh owed the most extreme behavior. The highest relative rate of disappearance was observed in fruits of the Blanqueta variety, and the lowest was observe d in those of Arbequina. The chlorophyll a/chlorophyll b ratio remained pra ctically constant during ripening, with a value very similar for Hojiblanca , Picual, Cornicabra, and Blanqueta, but much higher for Arbequina, implyin g that the structure of the photosynthetic apparatus is different in the la tter variety. In the five varieties studied, lutein was the slowest caroten oid to be degraded, so that its percentage in the fruits increased with rip ening, whereas beta -carotene was the fastest to disappear. In ripe fruits covered with anthocyanins, chloroplast pigments were retained in both skin and pulp, with the rate of disappearance being much higher in the latter.