title: Influence of temperature and fish thickness on the mass transfer kinetics during the cod (Gadus morhua) desalting process.
abstract: BACKGROUND
  The aim of this study was to analyse the influence of desalting temperature, fish thickness and desalting time on the mass transfer kinetics during the cod desalting process by physico-chemical analyses.
  
  
  RESULTS
  Both water uptake and salt loss increased with increasing temperature (15 °C > 10 °C > 5 °C) up to 24 h in 'thicker' pieces. The equilibrium achievement was faster in 'thinner' pieces and also with increasing temperature. Longer desalting times at 10 °C can be a good practice to be used during cod desalting at an industrial scale in order to obtain commercial products with higher yields. The faster mass transfer during desalting of 'thinner' pieces appears to follow three periods as a result of diffusion of the components (water, NaCl, and soluble proteins) because of the concentration differences, and pressure gradients due to expansion/shrinkage of the protein matrix, which is dependent on the NaCl content. The refractive index can be used by industry as an indirect measurement to determine the moment at which the 'thicker' samples are near the Z(NaCl) = Y(NaCl) equilibrium.
  
  
  CONCLUSIONS
  Optimum combinations between the process variables analysed are essential in order to speed up the mass transfer kinetics during cod desalting at an industrial scale. © 2016 Society of Chemical Industry.
authors: IPMA, I.P., Portuguese Institute for the Sea and Atmosphere, I.P., Division of Aquaculture and Upgrading, Avenida de Brasília, 1449-006, Lisbon, Portugal.|ICBAS-UP, Abel Salazar Institute for the Biomedical Sciences, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal.|CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.|CERNAS, College of Agriculture of the Polytechnic Institute of Coimbra, Bencanta, 3045-601, Coimbra, Portugal.
authors: Helena
authors: H
authors: Oliveira
authors: IPMA, I.P., Portuguese Institute for the Sea and Atmosphere, I.P., Division of Aquaculture and Upgrading, Avenida de Brasília, 1449-006, Lisbon, Portugal.|CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors: Amparo
authors: A
authors: Gonçalves
authors: IPMA, I.P., Portuguese Institute for the Sea and Atmosphere, I.P., Division of Aquaculture and Upgrading, Avenida de Brasília, 1449-006, Lisbon, Portugal.|CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors: Maria L
authors: ML
authors: Nunes
authors: ICBAS-UP, Abel Salazar Institute for the Biomedical Sciences, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal.|CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors: Paulo
authors: P
authors: Vaz-Pires
authors: CERNAS, College of Agriculture of the Polytechnic Institute of Coimbra, Bencanta, 3045-601, Coimbra, Portugal.
authors: Rui
authors: R
authors: Costa
mesh_terms: D000465:Algorithms; D000818:Animals; D055598:Chemical Phenomena; D003080:Cold Temperature; D004058:Diffusion; D029941:Fish Proteins / Q000032:analysis / Q000737:chemistry; D005511:Food Handling; D005520:Food Preservatives / Q000032:analysis* / Q000737:chemistry; D057141:Food, Preserved / Q000032:analysis; D005628:Frozen Foods / Q000032:analysis*; D048389:Gadus morhua; D007700:Kinetics; D055595:Mechanical Phenomena; D011174:Portugal; D011786:Quality Control; D012031:Refractometry; D017747:Seafood / Q000032:analysis*; D017673:Sodium Chloride, Dietary / Q000032:analysis*; D012995:Solubility; D014867:Water / Q000032:analysis
chemical_list: D029941:Fish Proteins; D005520:Food Preservatives; D017673:Sodium Chloride, Dietary; D014867:Water
keywords: Gadus morhua; cod; desalting; mass transfer kinetics; temperature; thickness