Impact de l’extrait aqueux de Rosmarinus officinalis L sur la qualité microbiologique d’une viande ovine de race Ouled Djellal issue des pâturages steppiques au cours de la conservation au froid.

Abstract

This work consists in following the antimicrobial effect of the aqueous extract of a medicinal plant Rosmarinus officinalis L (Rosemary) cultivated in the region of Naama (Algeria) vis-à-vis the germs responsible for spoilage of sheep meat. Ouled Djellel breed from steppe pastures in Bogtob wilaya of El Bayadh during nine (09) days of cold storage at 4 ° C. The extraction of the main active compounds of the plant was carried out by macerating the plant in water. The rosemary extract obtained after evaporating the solvent was diluted to 0, 20, 40, 60, 80, and 100%, respectively. Eighteen (18) samples of 300 g of meat each were taken aseptically from animal carcasses after 18 hours of soaking. Batches of 3 pieces of meat were then made up and stored individually in polystyrene trays. Each batch was treated on the first day with one of the extract concentrations prepared as before at a rate of 6 ml. The microbiological analyzes carried out on the experimental meat samples concerned: total aerobic mesophilic flora, Staphylococcus aureus, Pseudomonas, psychrotrophic flora and thermotolerant coliforms. The level of contamination by spoilage germs (total aerobic mesophilic flora, Staphylococcus aureus, Pseudomonas, psychrotrophic flora and thermotolerant coliforms) seems to decrease remarkably (p <0.01) during the 09 days of cold storage in the meat of leg of lambs. treated in particular with pure aqueous extract and diluted to 80% compared to that of the control, not having undergone the addition of any additive as a preservative. The aqueous extract of the studied plant species Rosmarinus officinalis L. can undoubtedly be an effective substitute for chemical additives such as nitrates and nitrites harmful to health often used in cold cuts and processed meats. Being rich in phenolic compounds, this extract has shown a real antimicrobial power vis-à-vis some germs responsible for food poisoning capable as a consequence of appreciably extending the shelf life of meats at 4 ° C.