Effect of a moderate electric field on the salting of Atlantic Salmon (Salmo salar): An experimental study and phenomenological understanding. (November 2020)

• Record Type: Journal Article
• Authors: Núñez, H.; Cavada, G.; Ramírez, C.; Moreno, J.; Cornejo, G.; Jaques, A.; Pinto, M.; Vega, O.; Simpson, R.
• Is Part Of: Food research international. Volume 137(2020)
• Publication Date: 2020-11
• Subjects: Salting process -- Fick's second law -- Moderate electric field -- Atlantic salmon (Salmo salar) -- Anomalous diffusion -- Equilibrium salt concentration -- Fractional calculus; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2020.109475
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: Moderate electric field (MEF) treatments enhance mass transfer in salmon salting. The use of an MEF increased the equilibrium salt concentration in salmon tissue. The diffusion process was shown to be anomalous (non Fickian) and subdiffusive. The fractional order varied with the MEF strength and salt concentration. Abstract: Salting is one of the oldest methods of preserving food. The main limitation of salting is its extended processing time due to slow salt diffusion. A moderate electric field (MEF) can improve the mass transfer rate through electroporation. Regularly, mass transfer processes are modeled with Fick's second law. However, due to the anisotropic nature of food microstructures, it might be more appropriate to use an anomalous model. The main objective of this study was to search for a phenomenological explanation for salt and water diffusion in the salmon brining process coupled with MEF. Salmon fillets were cut into finite cylinders (0.025 × 0.025 m) and brined in two salt concentrations (6 and 24% w/w NaCl) at 6 °C for 20 h. MEFs were applied in the range of 0 to 2 V/cm. The salt and water contents of the salmon were measured during the process. Fick's second law and anomalous model based on fractional calculus were used to describe the diffusion phenomena. The results showed that an MEF tended to reduce the brining processing time and increase the salt content of salmon. This effect is predominantly due to an increase in the equilibrium salt concentration in the salmon tissue. Mathematical analysis shows that the anomalous diffusion model is more suitable for representing the brining process, exhibiting superdiffusion behavior (α > 1). An MEF accelerates the salt mass transfer into salmon tissue even at lower temperatures, significantly reducing the processing time. In addition, the diffusion process can be characterized with an anomalous model.