Browsing by Author "Sous la direction de : Dr. Ir. Nahimana, Paterne"

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    Evaluation de l’activité antimicrobienne et antioxydante des huiles essentielles d’Eucalyptus Maidenii F. Muell., de Cymbopogon Citratus (DC.) STAPF, de Rosmarinus Officinalis L., de Bidens Pilosa L., d’Ageratum Conyzoides L. et de Moringa Oleifera Lam du Burundi et leurs applications dans la conservation de la viande hachée
    (UB, EANSI, 2025-12) Ndikuriyo, Thierry; Sous la direction de : Dr. Ir. Nahimana, Paterne; Nzoyisubiziki Japhet, MSc
    Minced meat is a highly perishable product, prone to microbial and oxidative spoilage. However, conventional preservation methods rely on chemical additives, which are often criticized for their potentially harmful effects on health and the environment. This work aims to evaluate the antioxidant and antimicrobial properties of essential oils extracted from Eucalyptus maidenii F. Muell, Cymbopogon citratus (DC.) Stapf (lemongrass), Rosmarinus officinalis L. (rosemary), Bidens pilosa L., Ageratum conyzoides L., and Moringa oleifera Lam, as well as to study their effectiveness in preserving minced meat. The antioxidant activity was measured using the free radical scavenging method with DPPH, at concentrations of 5%, 10%, 25%, and 50%, with ascorbic acid as the reference standard. The antimicrobial activity, on the other hand, was evaluated by applying the essential oils to microbial suspensions extracted from contaminated ground meat, at concentrations of 250, 500, and 1000 μg/mL, which were applied to the targeted microorganisms including total mesophilic aerobic flora (TMAF), Escherichia coli, Salmonella, and Staphylococcus. All the essential oils showed varying antioxidant power, with Cymbopogon citratus displaying the highest inhibition percentage (up to 47.84 ± 0.11000% at a concentration of 5%), while the essential oils of Eucalyptus maidenii and Rosmarinus officinalis showed lower antioxidant activity at this concentration (respectively: 15.8633 ± 0.00577 and 21.8267 ± 0.00577%). In terms of antimicrobial activity, the effects were monitored by microbial counts after 24, 48, and 96 hours. Lemongrass proved to be the most effective, completely inhibiting the microbial growth of all targeted microorganisms starting from a low concentration (250 μg/mL). In contrast, E. maidenii and R. officinalis showed partial inhibition of microbial growth at 250 μg/mL and 500 μg/mL, respectively, also observed for R. officinalis at 1000 μg/mL. These results highlight that certain local essential oils have genuine potential to improve food preservation by reducing microbial load and limiting oxidation, thereby opening promising prospects for the development of natural alternatives of food security.