Effect of Lemon Leaf Extracts on Bacterial Count and Keeping Quality of Minced Meat

Minced meat is among the most popular and widespread meat products. Despite its high nutritive value, the product is subjected to contamination with many kinds of microorganisms. Therefore, the aim of this work was to improve the keeping quality and safety of chilled minced meat by using lemon oil extracted from fresh lemon leaves. Lemon leaf oil (LLO) used at three concentrations (0.5, 1, and 1.5%) to assess their effect on the sensory attributes, chemical parameters (pH, total volatile nitrogen, and thiobarbituric acid), and bacteriological status including total bacterial count, Enterobacteriaceae count, staphylococcal count, coliform count, and Escherichia coli count of minced meat stored at 4°C for 12 days. The results revealed that the addition of different concentrations of LLO improved the sensory attributes of treated minced meat samples compared with control samples. Also, LLO improved the chemical quality of chilled minced meat as it decreased pH, TVN, and TBA values compared to control group. Furthermore, LLO reduced the different bacterial counts significantly. The concentration of 1.5% of LLO had the optimal significant effect on improving sensory, chemical, and bacterial quality compared to the concentrations 0.5 and 1%. The study concluded that when lemon oil is used as a natural antioxidant and antibacterial preservative for minced meat stored at refrigerated temperature, the shelf-life of the meat can be extended up to 12 days, compared to the control group which was completely spoiled at 6 days.