High pressure treatment of liquid whole egg and advantages of low temperature application

Abstract

High hydrostatic pressure in combination with controlled temperature could be an alternative process for prolonging the shelf life of liquid whole egg (LWE). As a first step of process optimisation, the equivalent lines of pressure-induced coagulation are provided at three different temperatures (5°C, 25°C and 45°C). The excess work of structure breakdown (ΔW) was calculated from rheological measurements and used as a parameter for the degree of coagulation. Below the line of ΔW = 5.0 kj/m³, the rheological properties of processed LWE were comparable to those of fresh LWE, considered as a critical value. Pressure treatment at higher temperature caused increased coagulation and allowed only a limited possibility of performing high pressure treatment. Furthermore, the inactivation kinetics of E. coli in LWE showed that temperature optima for inactivation could also be found in the low temperature region.

Key Words:

• High hydrostatic pressure
• Liquid whole egg
• Kinetics
• Rheology
• E. coli