Sodium alginate with added thyme essential oil as a new method coating for rainbow trout fillet

The effects of sodium alginate coating with added thyme oil on quality of rainbow trout fillet (oncorhynchus mykiss) during chilled storage (4±10 C) were examined over a period of 20 days. A solution of sodium alginate (3%) and sodium alginate with thyme oil (sodium alginate 3% + 0.5, 1 & 1.5% thyme oil) was used for coating. The control and the coated fish fillet samples were analysed periodically (every 5 days by 20 days) for chemical (PV, TBA, FFA, TVB-N & pH) and sensory characteristics. Statistical analyses showed that pH, texture and overall acceptability in coated samples were significantly better than the uncoated samples as there was no significant difference between all coated samples. Fillets with sodium alginate enriched with 1% and 1.5% thyme essential oil had least amount of PV, FFA, TVB-N, colour and odour. The fillets with sodium alginate enriched with 1.5% thyme essential oil had least amount of TBA. The results showed that the effect of the sodium alginate coating enriched with thyme oil on the fish fillet samples was to enable the good quality characteristics to be retained for longer period of time and to extend the shelf life during the chilled storage.