Relationship between the oil and sugar content in olive oil fruits from Moraiolo and Leccino cultivars during ripening

In our previous work (Cherubini et al., 2009), sugar concentration was proposed as an accurate, reproducible index for technological ripening of olive oil fruits. During 2009 crop season, sugar and oil content of olive oil fruits from Moraiolo and Leccino cultivars were measured during ripening. The sugar content of olive oil fruits was determined both by titration and by using a portable refractometer. A linear relationship was found, which was similar to that identified for Frantoio cultivar in our previous work. Evaluation of ◦Brix using a refractometer was found to be linearly correlated to the sugar content of olive oil fruits. It was confirmed that sugar concentration may be considered as a direct index for peculiar biochemical phenomenon of oil accumulation during ripening of olive oil fruits. Evaluation of ◦Brix could thus be useful for a simple, fast determination of the sugar content and, indirectly, the relevant oil content.