Physical and Rheological Properties of Egg Albumin Foams Are Affected by Ionic Strength and Basil Seed Gum Supplementation

Ali Rashidinejad,Ali Motamedzadegan,Seyed-Ahmad Shahidi,Saeed Mirarab Razi

doi:10.1155/2019/2502908

Abstract

In this study, the effect of ionic strength and basil seed gum (BSG) on the foaming properties of egg white albumin (EWA) was studied. The foam was prepared with 1% EWA (w/v) in the presence of different concentrations of sodium chloride (NaCl; 0, 0.5, and 1% w/v) and BSG (0, 0.1, and 0.3% w/v). The results showed that foam density and foam stability of EWA significantly (p<0.05) increased with an increase in BSG concentration (from 0 to 0.3% w/v). On the contrary, an increase in NaCl concentration (from 0 to 1% w/v) increased foam overrun but decreased foam density. Amplitude rheological parameters indicated an improvement in foam structure with increasing NaCl concentration. In addition, an elastic structure was obtained in the case of the foams with the higher concentrations of NaCl. Elastic modulus (G′) was higher than loss modulus (G″) in the frequency range, and there was low frequency dependency in all of the samples. In constant frequency of 1 Hz, tangent (δ) was the lowest in the sample containing 1% NaCl (w/v), but without BSG. There was a decrease in yield stress values with increasing BSG concentration; however, the increase in NaCl concentration led to an increase in yield stress. The highest yield stress (37 Pa) belonged to the sample containing 1% NaCl, but without BSG. Overall, it was found that both NaCl and BSG could substantially improve the rheological and foaming properties (in particular, foam stability) of egg white albumin.

Highlights

Foams are heterogenic systems, where gas is dispersed in a liquid phase [1]. e most common components for foam production are proteins, such as those present in egg
Foam Capacity (Overrun and Density). e effect of NaCl and basil seed gum (BSG) concentration on foam overrun and foam density is shown in Figures 1(a) and 1(b), respectively
The effect of ionic strength and BSG concentration on the physical and the rheological properties of egg white albumin (EWA) foams was investigated. e results showed that increasing ionic strength significantly (p < 0.05) improved foaming capacity of EWA

Summary

Introduction

Foams are heterogenic systems, where gas is dispersed in a liquid phase [1]. e most common components for foam production are proteins, such as those present in egg. E most common components for foam production are proteins, such as those present in egg. Foaming is considered as one of the most important properties of food proteins. Proteins and anionic polysaccharide mixtures have better surface-active properties compared to proteins alone, meaning that such mixtures can lead to formation of a more stable foam [2], mostly due to the increase in the viscosity of the corresponding solutions [2]. One aspect of the effect of polysaccharides on foaming properties of proteins is by modification of gas bubble distribution in the liquid that changes gas volume fraction and foam density [1]. The presence of polysaccharide can change the rheological properties of a solution because of its non-Newtonian rheological properties (e.g., viscoelasticity and thixotropy)

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