Pressure treatment can also be used to alter the functional
and sensory properties of various food components, especially
proteins. The tertiary and quaternary structures of molecules
which are maintained mainly by hydrophobic and ionic
interactions are beneficially altered by high pressure above
200 MPa (25). The hydrophobic and electrostatic interactions
are most affected but not the hydrogen bonds which stabilize
α-helical and ß-pleated sheets (27). Meat, fish, egg and dairy
proteins can be denatured with HPP in the absence of elevated
temperatures. Increased viscosity and opacity are obtained with
little change in fresh flavour. On the other hand, high pressure
has very little effect on low-molecular-weight compounds such
as flavour compounds, vitamins, and pigments compared to
thermal processes. Accordingly, the quality of HPP pasteurized
food is very similar to that of fresh food products. The quality
throughout shelf-life is influenced more by subsequent
distribution and storage temperatures and the barrier properties
of the packaging rather than by the high pressure treatments
(6, 7).