ANTIOXIDANT ACTIVITY OF ZATARIA MULTIFLORA BOISS. ESSENTIAL OIL ENCAPSULATED IN NANOLIPOSOME IN BROTH MEDIA AND MINCED BEEF

Abstract

Natural herbal antioxidants as additives in food and biological systems are interesting but their application in food formulations is problematic due to low dispersion in aqueous phase and susceptibility to oxidation. Encapsulation is a solution to increase water solubility protection from environment as well as masking odor and taste of new additives. In this study, liposome-encapsulated Zataria multiflora boiss was produced by heating method and encapsulation efficiency was optimized. Then antioxidant activity of free and encapsulated essential oil was compared using radicals 2-'2-diphenyl-1-picrylhydrazy (DPPH) and thiobarbituric acid reactive substances (TBARS) in minced beef. Results showed that the most important parameter affecting the microencapsulation efficiency is phosphatidylcholine. The most suitable encapsulation was achieved in condition includes phosphatidylcholine (2.5% w/w), ratio of essential oil to phosphatidylcholine (0.81% w/w), temperature (35°C) and time (42 min). In these conditions, the encapsulation efficiency reached to 54.4 %. Antioxidant activity of liposomal essential oil was significantly higher than free oil. The sensory evaluation of minced meat containing encapsulated essential oil was significantly higher than control (including free essential oil) (p≤0.01) (p. Minced meat containing 0.05% and 0.1 % w/w encapsulated essential oils showed suitable overall acceptance.