Effect of high pressure on fresh cheese shelf-life

The effect of high pressure (HP; 300 and 400 MPa for 5 min at 6 degrees C) on physico-chemical, microbial, color, texture and sensorial characteristics of starter-free fresh cheeses stored at 4 and 8 degrees C was studied. Physicochemical parameters considered were total solids, fat, total protein, pH, whey loss and water activity. The microbiological quality was studied, on cheeses stored at 4 and 8 degrees C, by enumerating aerobic mesophilic bacteria, lactococci, psychrotrophic bacteria, Enterobacteriaceae, Escherichia coli, molds and yeasts. Cheeses treated at 300 and 400 MPa, stored at 4 degrees C, presented a shelf-life of 14 and 21 days, respectively, compared to untreated control cheese, which presented a shelf life of 7 days. On the other hand, HP treatments modified the texture (more firm) and color (more yellow) compared to control cheeses. These changes were detected by instrumental and sensory analysis. (C) 2011 Elsevier Ltd. All rights reserved.