CONICET | Buscador de Institutos y Recursos Humanos

The application of high hydrostatic pressure (HHP) treatment hasbeen proposed to reduce the ripening time of cheese via modifications in theenzymatic activities or the substrate reactivity and exposure. Investigationshave been undertaken with either encouraging results or little impact accordingto the treatment conditions and the type of cheese, but information concerning theimpact of HHP on the ripening of hard cooked cheese is still lacking. In this report,we described the effect of HHP treatment on Reggianito cheese proteolysis. Forthat purpose, 1-d-old miniature cheeses were treated at 100 or 400 MPa and 20¨¬Cfor 5 or 10 min, while control cheeses in the trial were not pressurized. Allcheeses were ripened at 12¨¬C during 90 days. TheHHP did not affect gross composition of the cheeses, but microbial loadchanged, especially because the starter culture count was significantly lowerat the beginning of the ripening of the cheeses treated at 400 MPa than in controlsand cheeses treated at 100 MPa. Cheeses treated at 400 MPa for 10 min hadsignificantly higher plasmin activity than did the others; the residualcoagulant activity was not affected by HHP. Proteolysis assessment showed thatmost severe treatments also resulted in cheeses with increased breakdown of ¥ás1and ¥â casein. In addition, nitrogen content in soluble fractions was significantlyhigher in cheeses treated at 400 MPa, as well as soluble peptides and free amino acidsproduction. Peptide profiles and individual and total content of free aminoacids in 60-d-old treated cheese were as high as in fully ripened controlcheeses. We concludedthat HHP treatments at 400 MPa applied 1 day after cheese making increased the rateof proteolysis in Reggianito Argentino cheese, while 100 MPa treatments did notlead to significant changes.

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