The application of the Dehydration-Impregnation by Soaking (DIS) process in ternary solutions (water, NaCl, glucose syrup) at low temperature was proposed for the transformation of turkey meat. The knowledge of the properties of the solutions used combined with that of mass transport between the product and the solution made it possible to release a rational applicability of the DIS process for turkey meat, according to the final characteristics of the desired processed product. In order to free itself partly from the slowness of the diffusive mechanisms which govern mass transport during the DIS process and also to widen the potential range of the products being able to be obtained by poultry meat immersion in concentrated solutions, the Pulsed Vacuum Soaking (PVS) process in a salt-saturated solution was proposed. It consists of immersing the product in a solution and of subjecting it to a treatment alternating phases under residual pressure and phases at atmospheric pressure. PVS causes a strong increase of salt gain and a reduction in water loss, which has as a consequence an increase in the global mass yield. The principal variables of this process were identified and their effects on mass transport were quantified. This study showed the importance of the structure of the meat and the presence of occluded and/or dissolved gas in the meat. The tests carried out on meat and model gel made it possible to propose a model of representation of the phenomena intervening in mass transport during the PVS process. Thus, the vacuum treatment makes it possible to degas the pores of the meat and the atmospheric pressure restoration results in an infiltration of solution in these pores, the gases still present in these pores being then compressed. This infiltration also results in an increase in the heat-transferring surface between the meat and the solution. However, the infiltrated solution is very quickly diluted and this dilution decreases notably, even opposite, water transport. Finally, DIS and/or PVS operations sequencing was proposed to obtain certain products more quickly and to formulate other products, impossible to obtain by DII under satisfactory conditions.
Formulation and dehydration of poultry meat by soaking. Mass transfers study at atmospheric pressure and under vacuum.