Improvement in the Production of Smoked Trout Fillets (Salmo Gairdnerii) Steamed with Liquid Smoke

Abstract

A fish smoking process was applied using a combination of liquid smoke and steaming at pressures up to 1 bar above atmospheric pressure. Drying and brining prior to smoking have not shown any significant effect on the quality of the trout fillets. The nondried and dried for 4 h trout fillets prior to processing were assessed as slightly more acceptable products, processing yield, sensory analysis, instrumental color, pH, available lysine, polycyclic aromatic hydrocarbons (PAHs) and preservation time were estimated. The losses due to processing of the nondried samples were 23.7%, while 28.8% for those dried for 4h. The fillets processed at 1.5 and 2 bar steam pressure were assessed as highly acceptable. Lightness (L*) showed a decreasing trend due to pressure while redness (a*), and yellowness (b*) an increasing one. The destruction of available lysine was low (13.20% ± 1.01) and it was slightly dependent upon the process. No PAHs were detected. The preservation time, studied via total viable count, lactic acid bacteria, existence of Listeria monocytogenes, and sensory analysis, extended to more than 98 days at 4 ± 1 °C. The drying prior to processing seems to affect the preservation time. This processing technique is much simpler, faster, environmental effective, and leads to high quality smoked products.