EFFECT OF AVISHANE SHIRAZI (ZATARIA MULTIFLORA) AND CLOVE (SYZYGIUM AROMATICUM) ESSENTIAL OILS ON MICROBIOLOGICAL, CHEMICAL AND SENSORY PROPERTIES OF GROUND SHEEP MEAT DURING REFRIGERATED STORAGE

The objectives of this study were to examine the efficacy of Avishane shirazi (AEO) and clove (CEO) essential oils in controlling the microbial growth as well as in inhibiting the lipid oxidation and metmyoglobin (MetMb) formation in ground sheep meat during refrigerated storage. Total mesophilic counts (TMC), lactic acid bacteria (LAB) counts, coliform counts, yeast counts and Listeria counts were determined. Thiobarbituric acid (TBA) values, MetMb and sensory attributes (color, odor and overall acceptability) were also evaluated. The greatest effect of AEO was found in controlling the growth of LAB (1.2-3.4 log cycles) and coliforms (1-2.5 log cycles). The inhibitory effects of oils on TMC and yeast counts were minor, while both oils had strong and similar inhibitory effects on the Listeria populations. AEO significantly retarded lipid oxidation and inhibited MetMb formation. AEO and CEO had a noticeable effect on odor and color attributes of ground sheep meat, respectively. Both oils, particularly AEO, could help control the microbial growth and inhibit chemical changes in ground sheep meat during refrigerated storage.