Effect of olive ripeness on the oxidative stability of virgin olive oil extracted from the varieties Picual and Hojiblanca and on the different components involved
F. Gutierrez et al., Effect of olive ripeness on the oxidative stability of virgin olive oil extracted from the varieties Picual and Hojiblanca and on the different components involved, J AGR FOOD, 47(1), 1999, pp. 121-127
The initial stability of virgin olive oil depends on various factors, among
which are the variety and the degree of fruit ripeness. The former, which
genetically determines the composition of the olive and its oil, also marks
, to some extent, its stability. However, oil stability changes as the oliv
e ripens, so it is obvious that the degree of ripeness is an important fact
or. The oils were obtained by the Abencor system. Acidity, peroxide index,
UV absorption at 232 and 270 nm, sensory analysis, fatty acid composition,
tocopherols, phenolic compounds, orthodiphenolic compounds, sterols, pigmen
ts, and oxidative stability were determined, and the results were analyzed
statistically. During ripening there was a decrease in all of the parameter
s studied except linoleic acid, Delta 5-avenasterol, and oil content, which
increased. Virgin oils showed very good correlation between stability and
the concentrations of total phenols, o-diphenols, tocopherols, chlorophyll
pigments and carotenoids, linoleic and linolenic acids, total sterols, beta
-sitosterol, and Delta-5-avenasterol.