Effect of high pressures on the process of Edam cheese proteolysis†

High Hydrostatic Pressure Processing of Cheese

“…Results showed no significant differences in the proteolytic activity of enzymes from controls and frozen pressurized cheese. These results were similar to those reported by Iwańczak and Wiśniewska (2005) in which Edam cheese subjected to pressurization at 200 and 400 MPa for 30 min at room temperature directly after salting, and after 4, 6, and 8 wk of ripening, did not differ in proteolysis indexes from controls as measured by levels of nonprotein nitrogen, amino acid nitrogen, and pH 4.6 SN. In Garrotxa cheese pressurized at 50 MPa for 72 h at 14 °C 1 d after salting, levels of proteolysis were only slightly different from those in control cheese, with differences being less apparent after 28 d of ripening (Saldo and others 2002a).…”

“…Starter bacteria in Garrotxa cheese are lysed after an HHP treatment of 400 MPa, causing a release of peptidases that accelerate secondary proteolysis, whereas in Edam cheese, this effect does not occur. With regard to primary proteolysis, Saldo and others (2000) noticed an increase in the proteolytic activity of rennet during HHP treatments, whereas Iwańczak and Wiśniewska (2005) reported no significant differences in the proteolytic activity of enzymes in pressurized cheese and control, based on analysis of the content of 12% trichloroacetic acid (TCA)‐soluble nonprotein nitrogen compounds and 2% TCA‐soluble compounds.…”

“…On the other hand, pressure treatments modify the pH to an extent that depends on treatment conditions and cheese age. Research studies have shown a higher pH value of pressure‐treated cheese compared to controls in varieties such as Camembert (Kolakowski and others 1998), Cheddar (Rynne and others 2008), ewes’ milk cheese (Juan and others 2007a, 2008), fresh cheese (Sandra and others 2004; Okpala and others 2010), Edam (Iwańczak and Wiśniewska 2005), Garrotxa (Saldo and others 2000, 2002a), Gouda (Kolakowski and others 1998; Messens and others 1998, 1999), Manchego (Pavia and others 2000), mozzarella (Johnston and Darcy 2000), La Serena (Arqués and others 2006, Garde and others 2007), Pére Joseph (Messens and others 2000), and Paillardin (Messens and others 2001). This result is more pronounced at higher pressure levels, longer exposure times, and when applying treatments at an early stage of ripening, due to the release of colloidal calcium phosphate into the aqueous phase of cheese, LAB inactivation, or reduced ability of LAB to produce acid even when there is no apparent loss of cell viability as a result of damage to the glycolytic enzymes.…”

Effect of high-pressure treatment on microbiology, proteolysis, lipolysis and levels of flavour compounds in mature blue-veined cheese

“…Another possible mechanism for the colour changes due to HP treatment could involve the liberation of pigments of moulds from the cheese; however, no studies have been found for reference in this regard. In Cheddar cheese treated at 400 MPa at day 1 postmanufacture and vacuum packed, no significant differences were found in the gross composition of the cheese measured after 14 days of ripening (Rynne et al, 2008), whereas Edam cheese, treated after 4 and 6 weeks of ripening at 200-400 MPa, also showed no difference in water retention (Iwaczak & Winiewska, 2005). However, differences in the storage conditions (i.e., use of gold foil for blue-veined cheese and vacuum packaging for Cheddar) could significantly affect the changes in composition of the cheese.…”

“…the centre of the cheese, in contrast to smaller ones, which lead to increased levels of TCA-SN in the inner part but not the pH 4.6-SN fraction. In Edam cheese treated 4, 6 or 8 weeks post-manufacture, an initial decrease in pH 4.6-SN was observed directly after HP treatment at 200 and 400 MPa, but at the end of ripening similar levels were reached in all cheeses (Iwaczak & Winiewska, 2005). In Mozzarella cheese treated at 400 MPa for 5 min at day 1 post-manufacture, no significant changes in levels of pH 4.6-SN were observed over the ripening time of 35 days; also, in Gouda cheese, HP-treated at 50-400 MPa for 20-100 min, no significant effect was observed (Sheehan et al, 2005;Messens et al, 1999).…”