New controlled release material: aerated egg white gels induced by calcium ions

Abstract

by Fickian diffusion through the swelling matrix and it was faster for the gels with higher concentration of calcium. An increase in calcium concentration caused an increase in surface roughness of the aerated gels. There were linear correlations between the quadratic mean of the surface roughness and "n" coefficient from the Ritger and Peppas equation and between the maximum roughness size and "n". The increased calcium concentration made the gel microstructure more particulate and the surface rougher, which enabled faster proteolysis of the gel in an artificial stomach and faster diffusion of calcium ions.Keywords Aerated · Egg white · Gel · Release · Microstructure · Surface properties · Rheology Abstract The aim of the research was to use low-mineral egg white albumin isolate to obtain aerated calcium ioninduced gels and to investigate their aptitude as matrices for active ingredients release. Aerated gels were prepared by adding calcium ions to pre-heated protein dispersions with simultaneous aeration. 20 mM calcium concentration was an optimal concentration at which the maximum viscosity and hardness of the gels were found. For higher concentrations of calcium ions (25-30 mM), aerated gels were characterized by lower values of the moduli and tangent of the phase angle was larger for aerated gels which indicated more viscous character than that of non-aerated gels. Increased ions concentration causes higher aggregation of protein matrix and less smooth microstructure of the interface between the gel and air. An increase in calcium concentration from 5 to 30 mM caused an increase in an average bubble size. The release of calcium ions from aerated gels was measured in an artificial stomach. It occurred * Stanisław Mleko

Modeling the release of food bioactive ingredients from carriers/nanocarriers by the empirical, semiempirical, and mechanistic models

“…In order to investigate the contributions of diffusion and erosion mechanisms in the system, Peppas and Sahlin model was fitted to the experimental data. The authors stated that although this model can describe successfully the release process of bioactive agents in the pharmaceutical field, it is not widely used in food applications yet (Tomczynska‐Mleko, 2015; Tomczyńska‐Mleko et al., 2016).…”

Characterization of egg white gel microstructure and its relationship with pepsin diffusivity

“…Egg white proteins mainly including ovalbumin, ovotransferrin, ovomucoid and lysozyme, are widely available and show a well-balanced profile of amino acids with high bioavailability (Abeyrathne, Lee, & Ahn, 2013;Matsuoka, Takahashi, Kimura, Masuda, & Kunou, 2017). Besides their nutritional characteristics, the denaturation and aggregation behaviour of these proteins is of particular relevance toward manufacture of hydro-or emulsion gel structures which can act as nutrients or drug delivery systems (Drakos & Kiosseoglou, 2006;Opazo-Navarrete, Altenburg, Boom, & Janssen, 2018;Tomczyńska-Mleko et al, 2016). Without altering the protein composition of egg white, changes in pH and ionic strength, followed by heat treatment can produce gels with varying macro-and micro-structural designs (Nyemb, et al, 2016a,b).…”

Co-Gelation of Pumpkin-Seed Protein with Egg-White Protein

“…Egg-white gel has a very homogenous microstructure with very small particles (Figure 8c'). This phenomenon can be attributed to the fact that the egg-white protein isolate used in the research was an experimental preparation obtained by Kewpie Egg Corporation, which contained a very small concentration of ions [24,25]. Heat-induced gelation in the 0.2 NaCl solution resulted in a fine-stranded gel being obtained (Figure 8c') [26].…”