Principle of HPP

Any phenomenon in equilibrium (chemical reaction, Phase transition, change in molecular configuration) accompanied by a decrease in volume, can be enhanced by pressure. Thus HPT affects any phenomenon in food systems where volume change is involved and favors phenomena, which results in a volume decrease. The HPT affects non-covalent bonds (Hydrogen, Comic, Hydrophobic bonds) substantially as some non-covalent bonds are very sensitive to pressure, which means that low molecular weight food components (responsible for nutritional and sensory characteristics) are not affected, whereas high molecular weight components (whose tertiary structure is important for functionality determination) are sensitive. Some specific covalent bonds are also modified by pressure. High pressure technology acts instantaneously and uniformly throughout a mass of food independent of size, shape and food composition. Compression will uniformly increase the temperature of foods approximately 30 C per 100 MPa. The temperature of homogenous food will increase uniformly due to compression. An increase in food temperature above room temperature and to a lesser extent a decrease below room temperature increases the inactivation rate of microorganisms during HPT treatment. Temperatures in the range of 450 C to 500 C appear to increase the rate of inactivation of food.