Chapter 12. β-Lactoglobulin Aggregates from Heating with Charged Cosolutes: Formation, Characterization and Foaming

Impact of protein self-assemblages on foam properties

“…Consequently, the fact that these large aggregates were disulfide-bridged tends to prove that they were essentially formed by the aggregation of the non-native protein monomers. Similar results on the absence of intermediatesize soluble species upon heating b-Lg close to neutral conditions and in the presence of 100 mM NaCl had been reported by Renard (1994), while Unterhaslberger et al (2007) also claimed that the low amount of soluble aggregates with intermediate molecular weight formed upon heating b-Lg in presence of NaCl might be explained by their faster aggregation into larger aggregates.…”

“…The study of the effect of thermal treatment on the foamability and the foam stability of WPI at pH 7, carried out by Zhu and Damodaran (1994), emphasised the importance of the monomeric/polymerised protein ratio to improve foamability (optimum ratio 60:40) or foam stability (optimum ratio 40:60). Recently, Unterhaslberger, Schmitt, Shojaei-Rami, and Sanchez (2007) showed also that an amount of 80% soluble aggregates generated upon thermal treatment of WPI at neutral pH in the presence of NaCl enabled marked improvements of protein foamability and foam stability.…”

Rheological properties of protein films

“…Although there have been a number of studies on synthetic particles, many of these particles are unsuitable for biological or food applications. Exceptions might be considered to include some of the protein-polysaccharide complexes [86] or protein aggregates that have already been mentioned, where these are deliberately added as emulsifying or foaming agents [87]. However, such particles are quite different from the truly solid particles that act as classic stabilizers of Pickering emulsions.…”

Influence of protein heat treatment on the continuous production of food foams

“…For example, due to heat treatment, native b-lactoglobulin, the main protein in WPI, dissociates from a dimer to a monomer, exposing its thiol group and interior hydrophobic residues, and enabling thiol/disulfide exchange reactions; thus, denatured proteins may polymerise and form protein aggregates (Kazmierski & Correding, 2003). The resulting interfacial and foaming properties will therefore be a complex combination of the respective properties of aggregates, native and non-aggregated denatured proteins (Damodaran, 1997;Davis & Foegeding, 2004;Nicorescu et al, 2008b, Nicorescu et al, 2009a, Nicorescu et al, 2009bRullier, Novales, & Axelos, 2008;Schmitt, Bovay, Rouvet, Shojaei-Rami, & Kolodziejczyk, 2007;Unterhaslberger, Schmitt, Shojaei-Rami, & Sanchez, 2007). Zhu and Damodaran (1994) advocated that non-0963-9969/$ -see front matter Ó 2010 Elsevier Ltd. All rights reserved.…”