Effect of carboxymethyl cellulose edible coating containing Zataria multiflora essential oil and grape seed extract on chemical attributes of rainbow trout meat

Meat products, especially fish meat, are very susceptible to lipid oxidation and microbial spoilage. In this study, first, gas chromatography mass spectrometry (GC-MS) analysis of Zataria multiflora essential oil (ZEO) components was done and then two concentrations of ZEO, (1% and 2%) and two concentrations of grape seed extract (GSE), (0.5% and 1%) were used in carboxymethyl cellulose coating alone and in combination, and their antioxidant effects on rainbow trout meat were evaluated in a 20-day period using thiobarbituric acid reactive substances (TBARS) test. Their effects on total volatile basic nitrogen (TVBN) and pH were evaluated as well. The main components of ZEO are thymol and carvacrol. These components significantly decreased production of thio-barbituric acid (TBA), TVBN and pH level of fish meat. The initial pH, TVBN and TBA content was 6.62, 12.67 mg N per 100 g and 0.19 mg kg-1, respectively. In most treatments significant (p < 0.05) effects on aforementioned factors was seen during storage at 4 ˚C. The results indicated that use of ZEO and GSE as a natural antioxidant agents was effective in reducing undesirable chemical reactions in storage of fish meat.