Susceptibility of plasmin and chymosin in Cheddar cheese to inactivation by high pressure

High pressure (HP) processing has attracted considerable interest in dairy research in recent years; its effects on cheese have been reviewed by OʹReilly et al. (2001). HP treatment of cheese may influence several of its properties, e.g., for hard and semihard cheeses, such as Cheddar and Gouda, the most notable effects are on the texture and rate of ripening. HP treatment increased elasticity and improved organoleptic properties of Gouda cheese (Kolakowski et al. 1998). Messens et al. (2000) reported that, immediately after treatment at 400 MPa, Gouda cheese was less rigid and solid-like and more viscoelastic than untreated cheese. HP treatment also enhances the functional properties of Mozzarella cheese (Johnston & Darcy, 2000; OʹReilly et al. 2002).