Anthocyanin and colour evolution in naturally black table olives during anaerobic processing

The results of a study on the evolution of physicochemical parameters during processing of black olives, with particular emphasis on anthocyanins and colour, are reported. Olives of two cultivars collected at a technological black-ripe stage were processed by the traditional anaerobic system. At regular intervals, brines and olives were inspected for different parameters. The routine physicochemical values in brines and olives changed as expected. Total anthocyanin, cyanidin-3-glucoside and cyanidin-3-rutinoside content showed a rapid decrease at 15 days of processing, presenting apparently a zero-order kinetic, and later they completely disappeared. Chromatograms revealed other unidentified peaks. The colour stability of the olives was probably assured by the formation of new more stable pigments.