Selected physical properties of liquid egg products at pasteurization temperatures

The influence of temperature on the rheological properties and density of l iquid egg product at pasteurization temperatures was investigated. The dens ity of all these products decreased with increasing temperature, however, t he changes were different depending on the product. The change in density m ay be represented by simple linear equations. All the products showed pseud oplastic flow behavior that may be described by the Power-law model. Egg wh ite had the lowest power law index (n=0.552). Salted egg yolk had the highe st n value (>0.8), thus it is closer to Newtonian fluid in its behavior. Th is index did not vary greatly with temperature for whole egg and egg white But decreased with temperature for egg yolk and salted egg yolk. The lowest consistency coefficient (m=54.52mPa.s(n)) was observed for whole egg. Salt ed egg yolk had the highest m value (269.9mPa.s(n)). The m value increased with temperature for egg yolk and egg white, but decreased with temperature before showing an increase for salted egg yolk and egg white. The calculat ed Generalized Reynolds number was below 2100 for all the products. These r esults show that laminar flow exits during typical pasteurization of liquid egg products and therefore the minimum residence time is half the average resident time.