||Journal of Ecology of Health & Environment
||1- Mahmoud, E.A. , El-Geddawy, M.A.H , Abd El-Hamied, A. A. and Nassar. A. G
This investigation was carried out to study the possibility of using some natural substances as volatile oils substituted of synthetic chemical for improvement shelf- life of ground beef. Mincedbeef treated with some essential oils (cumin, black seeds, marjoram, rosemary and sage) with different levels0.25 and 0.50 %, and control sample (without any additions). The treated meat samples were stored at 4±1º C up to 15 day. Addition of volatile oils to minced meat reduced the total bacterial counts compared with control sample. Pyschrotrophic bacteria counts in all treatments at zero time were similar, but there is significant (p ≥ 0.05) difference between samples with progressive of storage periods. Pyschrotrophic bacteria counts reduced with addition of essential oil compared with control sample. Staphylococcus aureus counts at zero time was higher in control sample (4.30 104 CFU/g) compared with other treated minced beef samples contained essential oils and which ranged between 2.7 to 3.69 104 CFU/g. With progressive of storage period, Staphylococcus aureus counts was increased to 6.15 104 CFU/g in control sample. Whereas, Staphylococcus aureus counts was reduced and disappear in minced beef samples contained volatile oils as a results of inhibitory effects of antimicrobial substances. Colliform group counts at zero time were higher in control sample (4.50 104 CFU/g) in compared with other minced beef samples which ranged between 2.45 to 3.59 104 CFU/g in minced beef samples contained essential oils. Colliform group counts was significant (p≥ 0.05) increased to 8.65 104 CFU/g in control sample with progressive of storage periods.. Whereas, their counts were reduced and disappear in minced beef samples contained volatile oils cause with inhibitory effects of these substances. All treatments of minced beef were free from Salmonella at zero time or throughout the storage periods.