Technological evaluation of dried egg white prepared by different techniques

Abstract

Egg white was spray dried, using Egyptian fresh eggs, with and without glucose removal. Glucose depletion in egg white was carried out using bacteria, yeast and enzyme. Foam capacity and stability of liquid egg white was found to decrease after glucose was removed by the different methods used. Foam capacity was also decreased by dehydration, except for egg white in which enzyme was used for glucose removal. Foam was more stable in samples desugared by yeast and least stable in enzyme treated egg white. Both pan drying and spray drying methods had the same effect on foam capacity and stability of egg white. The pH value of liquid egg white was found to decrease by removing glucose and to increase by dehydration. The specific volume data and organoleptic evaluation of angel food cakes in which dehydrated egg white, imported dried egg white and fresh egg white were used, showed that the best method to prepare dehydrated egg white is by using enzymatic treatment for glucose removal before dehydration.Dehydration of egg white is carried out mainly by two ways, pan drying and spray drying processes. The drying process should permit the retention of certain valuable properties of the fresh egg white such as solubility, foaming capacity and palatability. I t was recommended that glucose must be removed prior to drying tq avoid MAILLARD reaction which results in browning and poor storage stability of products [ I , 23. Natural fermentation of Egyptian egg white was unsuccessful in removing glucose [3]. DARWISH et al. [4] studied the different methods that could be applied for preparing dried egg white as a new industry in Egypt. Egg white was dehydrated, with and without glucose removal. Glucose was removed by different methods including the use of bacteria, yeast and enzyme.The present study is concerned with the technological evaluation of dried egg white, prepared by the different techniques mentioned before. I t includes : -Effect of drying on the foaming capacity and foam stability of egg white.-As the hydrogen ion concentration is known to be an important factor in determining the foaming capacity of egg white, it was decided to study the effect of removing glucose and dehydration on the pH value of egg white.-Effect of the drying process on the palatability of egg white. Materials and methodsChicken eggs were obtained from the poultry farm of the Animal Husbandry Dept., Ministry of Agriculture. Cairo, Egypt. They were washed, then examined by candling [ 5 ] . Egg white was separated, blended and strained. The imported egg white powder that was used for comparison was spray dried, Swiss made.-Bacterial fermentation using Stv. Iactis in presence of 0 . 2 % yeast extract a t pH (3.0 and 30 OC [ 6 ] .-Bacterial fernientation using Aer. aerogenes a t pH 7.0 and 37 'C [ 6 ] .The methods used for glucose depletion in liquid egg white were:

Gelling properties of duck albumen powder as affected by desugarization and drying conditions

“…Glucose oxidase and catalase have been widely used to convert glucose into gluconic acid. It was demonstrated as the best method to prepare dehydrated Egyptian egg albumen, compared to the use of bacteria and yeast (Darwish & Sadek, 1978;Lechevalier et al, 2013). In addition, enzymatic method has been implemented in industrial scale prior to spray drying of hen egg albumen (Lechevalier, Jeantet, Arhaliass, Legrand, & Nau, 2007).…”