Résumé:
The first aspect treated in this work consists in determining the evolution of the physico-chemical parameters and the quality of olive oils extracted cold and hot and having undergone an enrichment in leaves of Rosmarinus officinalis L. at 5%. The oils studied belong to a Spanish variety, grown in the region of Hassi Mameche, Mostaganem-Algeria. The results obtained show that the extraction process and the dose of rosemary incorporated are two factors that significantly influence (P ≤ 0.01) the quality of olive oils. The cold process seems to decrease the acidity with a percentage of 16.86%; while the dose of rosemary had no influence. The peroxide index is also reduced by 27% during hot extraction, but this reduction did not exceed the limit set by the International Olive Oil Council. The UV in 232 and 270 and the Tbars are also very significantly reduced (p<0.01) using the cold process and adding rosemary; 29%, 17%, 15, respectively. The contents of chlorophyll and carotenoid pigments, phenolic compounds and flavonoids decreased by the hot process, but by the dose of rosemary added these values were enhanced. The second part of this study concerns the evolution of antioxidant activity. The best anti-radical power was recorded for the rosemary flavored oil, resulting from the cold extraction process; with an EC50=14.10 mg EAG/l of oil.
