Effects of Gelatin-Based Edible Films Enriched with Laurel Essential Oil on the Quality of Rainbow Trout (Oncorhynchus mykiss) Fillets During Refrigerated Storage

U ovom je radu ispitan utjecaj filma od želatine, obogaćenog eteričnim uljem lovorovog lista, na kakvoću fileta kalifornijske pastrve (Onchorynchus mykiss) skladištene na (4±1) °C tijekom 26 dana. Fileti su ribe omotani u filmove od 8 %-tne želatine, koji su sadržavali 0; 0,1 ili 1 % (volumena po masi želatine) eteričnog ulja lovora, te pakirani u vakuumu. Tijekom skladištenja određivani su: senzorske značajke sirove i kuhane ribe, mikrobiološki parametri (ukupan broj živih stanica, te broj psihotrofnih bakterija, enterobakterija i bakterija mliječne kiseline), kemijska svojstva (kemijski sastav, pHvrijednost, udjeli ukupnog hlapljivog baznog dušika, tiobarbituratne kiseline i slobodnih masnih kiselina, te peroksidni broj), boja, a periodički i trajnost proizvoda. Dobiveni rezultati pokazuju da je film od želatine, obogaćen eteričnim uljem lovora, prikladan za produljenje trajnosti fileta kalifornijske pastrve, ovisno o omjeru ulja. Kombiniranim učinkom ovoja od želatine i 1 %-tnog eteričnog ulja produljena je trajnost ribljih fileta na 22 dana, dok je kontrolni uzorak bio neprihvatljiv za konzumaciju već nakon 15 dana, a onaj omotan filmom bez eteričnog ulja nakon 20 dana.The effects of gelatin films enriched with laurel leaf essential oil on the quality of rainbow trout (Oncorhynchus mykiss) during refrigerated storage at (4±1) °C were examined over a period of 26 days. Fish fillets were wrapped with 8 % gelatin films containing 0, 0.1 and 1 % (by volume per mass) of laurel essential oil and vacuum packaged. Sensory (raw and cooked fish), microbiological (total viable counts, psychrotrophic bacteria counts, Enterobacteriaceae and lactic acid bacteria) and chemical (proximate composition, pH, total volatile base nitrogen (TVB-N), thiobarbituric acid (TBA), free fatty acid (FFA) and peroxide value (PV)) analysis, and colour measurement were carried out during the storage period and shelf-life was determined periodically. The obtained results showed that the gelatin film enriched with laurel essential oil was suitable for the preservation of rainbow trout fillet and the ability of laurel essential oil to preserve the film depended on its ratio. Combined effects of gelatin film and laurel essential oil (1 % by volume per mass) was efficient in maintaining the quality characteristics at an acceptable level up to 22 days of storage, while the control and gelatin film without the essential oil reached an unacceptable level at 15 and 20 days, respectively