Abstract

“Chemlali” is the main olive variety cultivated in Tunisia. Seasonal factors such as rainfall and temperature vary year to year influencing the composition and quality of virgin olive oil. This work aims to investigate the effect of the seasonal climatic variations on the quantity and the quality characteristics (free acidity, specific ultraviolet absorbance K₂₃₂ and K₂₇₀, fatty acid composition, chlorophylls and total phenols) of Tunisian “Chemlali” olive oil. Water and oil content increased with increasing rainfall and temperature respectively. The seasonal variations of climatic factors within the growing region did not affect the main legal quality indices of all oil samples. K₂₃₂, total phenol contents and oxidative stability increased at high temperature, while K₂₇₀ and chlorophyll content decreased.

Key words: Analytical quality parameters, chlorophyll, fatty acid composition, Olea europaea L., rainfall, temperature, total phenols.