ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF THYME AND CLOVE ESSENTIAL OILS AND APPLICATION IN MINCED BEEF

In this study, thyme and clove essential oils (EOs) were studied for their chemical composition, antioxidant, antiradical and antibacterial activity and application in ground beef. Carvacrol (75.27%) and eugenol (75.2%) were detected by gas chromatography-mass spectrometry analysis as the main components of thyme and clove EOs, respectively. Broth microdilution method showed all bacteria inhibited by the EOs, while Shewanella putrefaciens and Listeria innocua were the most resistant bacteria to thyme and clove EOs, respectively. EO treatment restricted the growth of artificially inoculated Salmonella typhimurium and native Coliforms in the ground beef. Antioxidant activity determined by ferric-reducing antioxidant power and 1,1 diphenyl-2-picrylhydrazyl methods demonstrated that clove EO had higher in vitro antioxidant activity than thyme EO. Similar results were obtained in ground beef application using 2-thiobarbituric acid value. EOs of clove (2MIC) exerted remarkable higher antioxidant activity in ground beef than EOs of thyme (4MIC), which represent valid alternative antioxidant in meat products.