The effect of thyme (TEO) and oregano (OEO) essential oils as well as modified atmosphere packaging (MAP)
in extending the shelf life of fresh lamb meat stored at 4 °C was investigated. In a preliminary experiment TEO
and OEO were used at concentrations 0.1 and 0.3% v/w while MAP tested included MAP1 (60% CO2/40% N2)
and MAP2 (80% CO2/20% N2). Microbiological, physicochemical and sensory properties of lamb meat were
monitored over a 20 day period. Sensory analysis showed that at the higher concentration both essential oils
gave a strong objectionable odour and taste and were not further used. Of the two essential oils TEO was more
effective as was MAP2 over MAP1 for lamb meat preservation. In a second experiment the combined effect of
TEO (0.1%) and MAP2 (80/20) on shelf life extension of lamb meat was evaluated over a 25 day storage period.
Microbial populations were reduced up to 2.8 log cfu/g on day 9 of storage with the most pronounced effect
being achieved by the combination MAP2 plus TEO (0.1%). TBA values varied for all treatments and remained
lower than 4 mg MDA/kg throughout storage. pH values varied between 6.4 and 6.0 during storage. Color
parameters (L and b) increased with storage time while parameter (a) remained unaffected.
Based primarily on sensory analysis (odour) but also on microbiological data, shelf life of lamb meat was
7 days for air packaged samples, 9–10 days for samples containing 0.1% of TEO and 21–22 days for MAP
packaged samples containing 0.1% TEO