Swelling and shrinkage regimes during the acidic marination of meat in presence of salt

Meat immersion in acidic marinades causes transfer of marinade solutes to the food and leakage of meat components: soluble ions and molecules. The main consequences observed are changes in functional properties under electrostatic phenomena and depolymerisation affecting myofibrillar proteins. In the particular case of immersion in marinades with wide ranges of combined NaCl and acid contents, there is little data available on mass variations and regimes of water and solute transfer. The objective of this work was to identify the material transfer mechanisms during immersion of a meat proteic matrix in acidic aqueous marinades, in a wide domain of ionic strengths. Turkey breast cubes (Pectoralis major) were treated by immersion in aqueous marinades. Response surface methodology was used to represent the dynamics of mass and solutes transfer. The mass transfers of water, acid and NaCl in turkey meat cubes were evaluated at various molalities of acetic acid and NaCl. High mass yields (mass gain > 0.3 kg kg), obtained for the marinades most dilute in acid, were found only in the absence of NaCl. In the case of acidic marinades with low salt concentration, high solute flux densities were observed upon the start of immersion, as well as solute transfer velocities greater than those in water. This phenomenon may be explained by the superimposition of material diffusion and transport phenomena caused by a fall in internal filtration pressure due to the expansion of the protein matrix. The works reported in this paper have been partly extracted from the article from Goli et al. [1] published in Journal of Food Engineering, DOI 10.1016/j.jfoodeng.2010.12.010.