The effect of olive fruit maturation in Spanish style fermentation with a controlled temperature

The influence of maturation of different olive fruit varieties and the effect of these olives fermented at room temperature in a spontaneous fermentation were studied. Also, table olives from Carrasqueña variety harvested in two consecutive weeks in green stage of maturation, were fermented at different thermal temperature by heat transfer to the brine. Initially, an olive growth characterization was carried out. The largest variety was “Manzanilla Cacereña” and presented less texture and the lowest total phenolic and antioxidant activity. However, “Carrasqueña” variety, which had the highest firmness, showed a slower size. The color index of “Manzanilla Sevillana” was rather higher than the color index of the other varieties. After fermentation process, the highest color index and free acidity in “Manzanilla Sevillana” table olive could be caused by the highest temperature of the brine achieved. In general, the varieties studied had a good texture during fermentation. On the other hand, the effect of thermal applications in table olive color was higher when the olives were harvested later and by thermal application. Finally, the effect of thermal application depended on initial maturation stage achieving an increase of phenols with determined temperatures and conditions.