Comparative Antibacterial and Preservative Effects of Aqueous Garlic and Clove Extracts, Sodium Nitrite and Sodium Benzoate in Fresh Minced Meat

Abstract

This study aimed to evaluate the antibacterial and preservative efficacy of aqueous extracts of fresh garlic (Allium sativum L.) and clove (Syzygium aromaticum), used individually and in combination, and to compare their efficacy with the synthetic preservatives sodium nitrite and sodium benzoate in fresh minced beef. Bacteria associated with meat spoilage were isolated and identified, including staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Vibrio mimicus. The antibacterial activity of the plant extracts was evaluated using the agar well diffusion assay at concentrations ranging from 10% to 100%. preservative efficacy was further assessed in experimentally inoculated minced meat stored at 4 and 25 C⁰ for 24 and 48h.The results showed that garlic extract exhibited notable antibacterial activity, with inhibition zones reaching up to 40mm, while Clove demonstrated considerable activity, particularly against V.mimicus. The garlic- clove combination exhibited the highest overall antibacterial activity among the plant extracts, with enhanced efficacy under refrigerated conditions. Complete inhibition of E. coli and V. mimicus and marked reduction in S. aureus counts were observed following treatment with the garlic- clove combination. Among the synthetic preservatives, sodium nitrite demonstrated the highest preservative efficacy, completely inhibiting the tested bacteria under refrigerated conditions. Overall, the findings indicate that garlic and clove, particularly when used in combination, have promising potential as natural preservatives for minced meat and may contribute to reducing reliance on synthetic chemical preservatives while maintaining product quality.