The effect of chitosan coatings enriched with garlic extract and coriander essential oil on the shelf life of rainbow trout ( <i>Oncorhynchus mykiss</i> ) fillet stored at 4 °C
Maryam Foromandi, Mohammadreza Khani
Abstract
Summary This study was conducted to evaluate the effect of chitosan coating enriched with garlic extract (GE) and coriander essential oil (CEO) on the shelf life of rainbow trout fillet. Treatments were prepared with chitosan coating (2%) containing GE and CEO (0.1% and 0.5%) both separately and in combination. The results showed that GE and CEO had significant effects on peroxide value (PV), thiobarbituric acid (TBA), total volatile basic nitrogen (TVB‐N), total viable (TVC) and psychrotrophic (PTC) counts in fillet samples during storage. It was observed that an increase in the concentration of GE and CEO in the coatings would lead to a significant decrease in the amounts of PV, TVB‐N and TVC. The concentration of 0.5% CEO was more effective than GE on PV, TVB‐N and microbial counts. The treatment coated with chitosan containing 0.5%GE + 0.5%CEO had the lowest PV (5.56 mEq/kg), TBA (2 mg MDA/kg), TVB‐N (32.57 mg N2/100 g), TVC (7.12 log CFU/g) and PTC (5.22 log CFU/g) on the 12th day of storage. The results indicated that the chitosan coating enriched with 0.5%GE + 0.5%CEO can extend the shelf life of refrigerated trout fillets for 6–9 days compared to the control and chitosan alone samples.