Albumen foam stability and s-ovalbumin contents in eggs coated with whey protein concentrate

Abstract

Food products such as breads, cakes, crackers, meringues, ice creams and several bakery items depend on air incorporation to maintain their texture and structure during or after processing. Proteins are utilized in the food industry since they improve texture attributes through their ability to encapsulate and retain air. The objectives of this work were to quantify s-ovalbumin contents in albumen and to determine alterations in egg white foam stability in fresh eggs, and in eggs coated and non-coated with a whey protein-based concentrate film (WPC), stored at 25°C for 28 days. The volume of drained liquid was higher in non-coated eggs than in coated eggs stored at 25°C at all storage periods. The difference on the third day of storage was in the order of 59% between coated and non-coated eggs, while on the twenty-eighth day it was 202%. During the storage period, an increase in pH and drainage volume was observed for non-coated eggs. After three days, the non-coated eggs showed a s-ovalbumin content 33% higher than coated eggs; this increase jumped to 205% at 28 days of storage. There was a positive correlation between s-ovalbumin content and the volume of drained liquid for coated and non-coated eggs; in other words, when the s-ovalbumin content increased, there was an increase in the volume of drained liquid and a decrease in foam stability. WPC coating maintain egg quality, since it is an effective barrier against the loss of CO2, avoiding changes in the pH of egg white

Albumen protein and functional properties of gelation and foaming

“…The stability in these cases is obtained only when the quantity of ovomucin is regular (MacDonnel et al, 1955). Alleoni & Antunes (2004) observed positive correlation between the content of s-ovalbumin and the volume of drained liquid of the eggwhite foam in hen eggs with or without whey concentrate protein coating. The volume of drained liquid increased and the foam stability decreased with increasing s-ovalbumin contents.…”

“…The conversion of ovalbumin to the extra stable form s-ovalbumin results from differences in the structure of covalent bonding (Zabik, 1992). When eggs are covered with oil, coated with whey concentrate protein (Alleoni & Antunes, 2004), or stored under refrigeration, this conversion is delayed as a result of the lower carbon dioxide loss by the pores of the egg shell. Alleoni (1997) evaluated effects of storage periods and two temperatures on poultry eggs.…”

A study of the factors affecting the foaming properties of egg white - a review

“…It has been known that pH increases with storage and as a consequence, part of the egg white n-ovalbumin is transformed into s-ovalbumin (less hydrophobic then n-ovalbumin). This interferes with the formation of a cohesive film on the air-water interface, causing a decrease in foam stability, and thus the correlation between s-ovalbumin content and the volume of drained liquid is positive (ALLEONI & ANTUNES 2004).…”

Effect of storage time on quality and functional properties of eggs from hens included in conservation programme in Poland

“…Stwierdzono natomiast, że stabilność piany zmniejszała się wraz z wydłu-żaniem czasu przechowywania. Niszczenie struktury piany można tłumaczyć dysproporcjonowaniem pęcherzyków w czasie, gdyż ulegają one zmniejszaniu z powodu ruchów powietrza z wnętrza, gdzie panuje wyższe ciśnienie [1,8,14]. Kolejnym zjawiskiem osłabiającym strukturę piany jest drenaż.…”