The effect of high-pressure treatment at 300 MPa on ripening of ewes' milk cheese

The effect of high-pressure (HP) treatment (300 MPa for 10 min) applied on day 1 or 15 of ripening on the proteolysis, lipolysis and sensory characteristics of ewes' milk cheese was investigated in real industry conditions (full-size cheese processed using an industrial HP machine). HP treatment increased the hydrolysis of beta-casein at all stages of ripening. Furthermore, at 90 days of ripening, higher hydrolysis of alpha(s1)-casein was found in HP-treated cheeses than in control cheeses. HP treatment applied on day 1 of ripening considerably increased the production of free amino acids. However, this treatment significantly changed the final sensory characteristics of cheeses; the texture of cheeses treated on day 1 became softer, more elastic and less crumbly, and the scores for taste, odour and aroma quality decreased compared with control cheese. Cheeses HP-treated on day 15 of ripening were similar to control cheeses, but with a more homogeneous protein network and a less crumbly texture; these cheeses had the highest percentage of short-chain fatty acids and were preferred by the panel. (0 2007 Elsevier Ltd. All rights reserved.