Journal of Food Engineering, Vol.166, 86-94, 2015
On the influence of storage duration on rheological properties of liquid egg products and response of eggs to impact loading - Japanese quail eggs
The eggs of wild-type European-originated quails were stored for I, 2, 3, 4, 6, 8, 10, 12, 14, and 16 weeks at constant temperature 4 degrees C. The three groups of parameters describing the egg quality were obtained. First of all the egg quality parameters were described in terms of egg weight, shell weight, yolk height, albumen height, albumen index, yolk index, Haugh units, and egg weight loss. In the next step the rheological behaviour of liquid egg products (egg yolk, egg white and whole liquid egg) was studied using a concentric cylinder viscometer. Flow curves of all liquid egg products exhibited Non-Newtonian behaviour. Experimental results were described using both of Herschel-Bulkley model and Oswald-de Waele model. The difference between results of these models can be neglected. The effect of the storage duration on the rheological behaviour is different for the different liquid egg products. The eggs were also loaded by the non-destructive impact. The response of eggs to impact loading was described by the time history of eggshell surface displacement. The storage duration significantly affects the eggshell response to the impact. The explanation of relation between rheological behaviour and this response is briefly outlined. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords:Egg quality;Japanese quail;Haugh units;Storage duration;Non-Newtonian fluid;Non-destructive impact;Surface displacement