ABSTRACT
Salting of cheese is usually carried out by brine immersion (BI) for a lengthy period of time (24-48 h, depending on the cheese size), and this causes technological and quality problems in cheesemaking. The process implies the management of great amounts of brine and the development of sharp salt concentration profiles in the cheese pieces, which may provoke ripening problems in some cases (Guinee and Fox, 1987). Recently, a new salting procedure has been described (vacuum impregnation, VI), which makes the salting process shorter (thus reducing the involved brine volumes) and the salt concentration profile in cheese flatter (Chiralt and Fito, 1997; Andrés et al., 1997). This new process is based on the action of hydrodynamic
mechanisms (HDM) associated with pressure changes. In the VI process, vacuum pressure is applied in the salting tank at the beginning of the process for a time t
,
after which the atmospheric pressure is restored for a time t
. During the vacuum period, the occluded gas in the pressed curd is expanded and flows out. When atmospheric pressure is restored, the residual gas is compressed, leading to the entry of the external brine into the curd pores. In this way, a greater salt uptake occurs in the cheese pieces than when using the conventional immersion for the same salting time, and a different salt profile is achieved (Andrés et al., 1997).
