Abstract

The main limitation of salting is its extended processing time, mainly caused by the slow diffusion of salt into the muscle tissue. The diffusion process can be accelerated by different technologies such as moderate electric fields (MEF) and CO2-laser microperforations. The main objective of this research was to evaluate the implementation of a combined MEF-CO2 -laser-microperforation treatment on the acceleration of the salting process in Atlantic salmon (Salmo salar) and its influence on the effective diffusion coefficient (D-eft). Salmon fillets were cut in cylinders. Microperforations at 50 and 100% depth into salmon tissue were produced axially with a 100 W CO2 laser. For MEF treatment an electric field strength of 1 V/cm was used. Salt concentrations along time were analyzed through Fick's second law and anomalous diffusion models, considering a finite cylindrical geometry. As a result, treatment with micropores-MEF achieved a salt concentration of 3.5% after 4 h, while the control required 12 h to reach the same salt concentration. When both technologies were simultaneously applied, both D-eft and final equilibrium salt concentration were increased, thus resulting in a significant reduction in salting time. The mathematical analysis showed good fit through the anomalous, presenting a sub-diffusive (alpha( ) 1) behavior for all treatments. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.