Olives vertes Sigoise au Rosmarinus officinalis L., élaborées par le procédé Espagnol : Effets antioxydants et impacts sur la qualité au cours du stockage.

Abstract

This work consists in determining the effect of adding the leaves of Rosmarinus officinalis L. Harvested in the region of Naama in the south of Algeria on the quality and keeping qualities of green olives of the SIGOISE variety produced by the Spanish process. The process of making the olives consists first of all in soaking them for 8 hours in 5 l of NaOH solution prepared at 2%, then washing ahem several times with water and finally letting them ferment for two months in brackish water with 1.1% NaCl. Three batches of three boxes containing 500g of olives were made up at the start of the fermentation phase just after the olives washing operation. Rosemary leaves were added at this time to the olive samples from each lot at 0, 10 and 15%, respectively. The physicochemical analyzes were carried out in triplicate at the end of the production of the table olives and focused on the determination of the main bioactive compounds and the antioxidant activity of rosemary, the evaluation of the pomological criteria of the olive, the assessment of the quality of the pulpe, the identification of quality indice, as well as the fatty acid profile of the oil and the assessment of the organoleptic quality of the olives by a jury made up of 10 panelists. After 30 days of fermentation, the physico-chemical parameters of the olive pulp showed a remarkable decrease (p<0.01) in pH and a notable increase in acidity depending on the addition of rosemary; while the fat, ash and moisture levels are acceptable and remain within normal values. The addition of rosemary leaves markedly increased the phenolic compound and flavonoid contents of table olives during their storage. The strong antioxidant activity of these compounds even prevents the oxidation of the lipid fraction of the fruits whos fatty acid profile has been significantly enriched (p<0.01) by 18.26% in the oleic, 3.15% in linoleic acid, 3.14% in PUFA and 0.82% MUFA. Finally, the sensory analysis revealed that the table olives prepared and preserved with the addition of rosemary leaves were the most appreciated by the panellists.