Rheological Properties of Liquid Egg Products (LEPS)

Abstract

Rheological properties were determined at 4°C (refrigerated temperature), 25°C (room temperature), 60°C (pasteurization temperature) for liquid whole egg (LWE) and liquid egg yolk (LEY) and 4, 25, 55.6°C for liquid egg white (LEW) by using concentric cylinder viscometer. The shear rate range was 8 to 53.7 s -1 for LEW and LWE, and 1 to 34 s -1 for LEY. Selected physical properties (e.g., density) of LEPs were studied at broad range of temperatures from 4°C to 60°C. All liquid egg products (LEPs) exhibited mildly shear thinning (pseudoplastic) behavior. Experimental data of LWE and LEW successfully fitted Herschel-Bulkley model, LEY data were well described by power law model. LEW and LWE showed thixotropy and time-dependency at their pasteurization temperatures (55.6°C for LEW, 60°C for LWE) and considered being time-independent below these temperatures. LEY exhibited time-dependent behavior at 4°C and 60°C. But its rheological behavior showed no thixotropy and time-dependency at room temperature. The density of all three products decreased with increasing temperature. Density data were correlated by polynomial models (r 2 > 0.99).

Ohmic Heating of Liquid Whole Egg: Rheological Behaviour and Fluid Dynamics

“…In the open literature, there was no information on the activation energy value for the ohmically heated liquid whole egg according to the authors' best knowledge. Therefore, this value was compared with values of conventionally heated liquid egg products, reported by Atilgan and Unluturk (2008) for the liquid whole egg as 10.523 kJ/mol and Telis-Romero et al (2006) for the egg yolk as 44.195 kJ/mol. On the other hand, it has been obtained in other part of this study that the activation energy for apparent viscosity of the liquid whole egg was higher for the conventional heating than the ohmic heating having same thermal history with it (unpublished work).…”

Effect of egg storage duration on the rheology of liquid egg products

“…In the 1st, 2nd and 4th week of storage the egg yolk exhibits typical thixotropic behaviour as is described in (Atilgan and Unluturk, 2008). In other weeks of storage there are shown timedepend behaviour of apparent viscosity (Riscardo et al, 2005).…”

“…Several researchers (Kaufman et al 1968;Cornford et al, 1969;Scalzo et al 1970;Tung et al, 1971;Hamid-Samimi et al 1984;Ibarz and Sintes, 1989;Lee et al, 1999;Punidadas and McKellar, 1999;Telis-Romero et al, 2006;Toyosaki, 2010) studied the rheological characteristics of egg and reported Newtonian as well as time-dependent Non-Newtonian flow behaviour of egg. These works are summarized in (Atilgan and Unluturk, 2008). Most of these studies have been usually carried out with only egg yolk.…”

On the influence of storage duration on rheological properties of liquid egg products and response of eggs to impact loading – Japanese quail eggs

“…The use of these products in food industry needs knowledge of their rheological properties. These properties have been mostly studied for liquid egg products of chicken eggs (Ibarz and Sintes, 1989;Adeogun and Amole, 2004;Atilgan and Unluturk, 2008).…”