Résumé:
This work focused on the development of a medicinal plant Rosmarinus officinalis L
(Rosemary) growing spontaneously in the Naama region. Algeria. The study consisted of
monitoring the antimicrobial effects of the plant extract on a pathogenic germ
(Staphylococcus aureus) implicated in food poisoning during 9 days of storage of the ovine
leg meat pastures at Bougtob in the El Bayedh wilaya. Algeria.
Extraction of the main active ingredients of the plant was carried out by maceration of the
plant in a 80/20 hydroethanol mixture (solvent / water, v / v). The rosemary extract obtained
after evaporation of the solvent was diluted to 20, 40, 60, 80, and 100%, respectively.
Fifteen samples of 300 g of meat were randomly made on sheep carcasses after washing,
then sanitized under UV, then contaminated with 2 ml of inoculum of a reference strain
(ATCC 25923) of Staphylococcus aureus and distributed in batches. 3 pieces (of 300 g) of
meat. Samples from each lot were processed by adding rosemary extract at 0, 3, 6, 9 and 12
ml, respectively, and stored in sterile pouches for 9 days at 4 ° C. Several measurement
techniques have been carried out in triplicate tests including: direct contact method, disk
method, Minimal Inhibitory Concentrations and Bactericides (MIC and CMB). The results
were analyzed for variance and averaged by Newman and Keuls. The hydroethanolic extract
of Rosmarinus officinalis L exhibited, especially in its pure state, an antimicrobial activity of
interest and close to gentamicin with respect to Staphylococcus aureus. The mode of action of
this extract against the studied germ is of bactericidal type.
Compared to the control, the addition as a natural additive to variable amounts of rosemary
extract of 1, 2, 3 and 4 ml per 100g of meat allowed reducing to 72, 85, 95 and 98%
respectively of level of Staphylococcus aureus contamination of the experimental products
kept cold at 4 ° C for 9 days.
