Ripening control of Manchego type cheese salted by brine vacuum impregnation

A new salting procedure was tested in Manchego type cheeses in order to shorten this processing step by decreasing the initial salt gradient in the cheese. This procedure was based on a fast mass transfer mechanism (the hydrodynamic mechanism) which acts when pressure differences are applied to porous products immersed in a liquid phase. The effective porosity of the studied cheese of cheese in was 0.049 as established by the hydrodynamic mechanism. This value represents the introduction of 1.03 g NaCl 100 g(-1) the cheese pores, when a 19% (w/w) brine was used, at 37 mbar (absolute) of vacuum pressure. This quantity agreed with the salt content in this experiment. The duration of the new salting process step was 2 h. The hydrodynamic mechanism is based on the supposition that salt ions penetrate the internal part of the cheese through pores. Water loss during ripening was controlled by the external drying rate for the cheese. Vacuum-impregnated cheeses always had a higher water content as a consequence of lower drying rates during the brine immersion period. Nevertheless, the differences in water content neither affected the change in pH nor the ripening process during the maturation of the cheese. (C) 1997 Elsevier Science Ltd.