Current ways to modify the structure of whey proteins for specific functionalities—a review

Abstract

The native whey proteins have been intensively used in a multitude of food applications due to their high nutritional, biological, and versatile technofunctional properties. The range of applications of whey proteins has further been extended in the last decades by the use of whey protein aggregates offering new technofunctional properties. These properties are directly dependent on the structure of whey protein aggregates, i.e., their size, shape, density, surface properties, and the type of bonds maintaining proteins together in the aggregates. In this review, after a brief description of the major whey proteins, we examine the most important advances reported to date pertaining to the available approaches to modify the structure of whey proteins for specific functionalities. Our laboratory, Science and Technology of Milk and Eggs, has contributed significantly to the advancement of knowledge on the structure-function relationships of whey proteins either in the native or denatured/aggregated forms. Our expertise and research approaches are highlighted throughout some selected results accumulated during the last decade in comparison with results from the literature.

Effect of sodium triphosphate on particle size of heat‐induced whey protein concentrate aggregates

“…It has been proposed that fractal aggregates resulted from self‐aggregation are dominant at higher protein concentrations (Fuente et al., ; Guyomarc'h et al., ; Nicolai et al., ). However, most of the particles in the WPC‐Na 5 P 3 O 10 aggregates were not fractal aggregates as reported (Dissanayake, Ramchandran, Piyadasa, et al., ; Nicolai et al., ; Phan‐Xuan et al., ), but their particles were more regular and smoother as spheres than that in WPC aggregates (Figure b 2 ).…”

“…Salts (usually NaCl or CaCl 2 ) can beaded to whey protein solutions to form aggregates with different morphologies and sizes, suggesting that the net charge of the native proteins (tunable by pH or ionic strength) is a crucial parameter for the formation of spherical particles. Increasing the ionic strength leads to charge screening and hence widens the pH range over which spherical particles can form (Baussay, Bon, Nicolai, Durand, & Busnel, 2004;Guyomarc'h et al, 2014;Homer et al, 2018;Mercad-Prieto, Paterson, & Wilson, 2009;Phan-Xuan et al, 2013;Pouzot, Durand, & Nicolai, 2004).…”

“…Thermal treatment is one of the most commonly utilized processing methods that has greatly expanded the application of WP in food-related products (Chung, Degner, & Mcclements, 2014;Famelart, Schong, & Croguennec, 2018;Torres, Janh, Mikkelsen, & Ipsen, 2011;Wang, Bao, Hendricks, & Guo, 2012;Zhang, McCarthy, Wang, Liu, & Guo, 2015). Thermal treatment above denaturation temperature (50-75°C) results in unfolding of the compact structure of WP, exposure of the buried apolar groups of polypeptide chains and sulfhydryl/disulfide exchange chain reactions via activated thiol groups (Dissanayake, Ramchandran, Piyadasa, & Vasiljevic, 2013;Guyomarc'h et al, 2014). WP, mainly α-lactalbumin (α-La) and βlactoglobulin (β-Lg), forms aggregates cross-linked by intermolecular disulfide bonds and noncovalent interactions.…”

Functional and Engineered Colloids from Edible Materials for Emerging Applications in Designing the Food of the Future

“…A number of studies have reported the use of whey protein products including whey protein isolate (WPI), concentrate (WPC), and hydrolysate or its components for the preparation of protein‐based colloids to deliver bioactives and micronutrients . Due to their high water solubility and due to the fact that they are present in the form of monomers and dimers in aqueous dispersions, whey protein–based colloidal structures have often been obtained through thermal aggregation . When globular proteins are subjected to heat denaturation, they aggregate irreversibly and form microgels, fractal, or fibrils, depending on the pH conditions ( Figure ).…”

Influence of the Protein Particle Morphology and Partitioning on the Behavior of Particle-Stabilized Water-in-Water Emulsions

“…The reason is that they were small compared to the correlation length of the of the polymers solutions so that the free energy does not significantly decrease when a native protein enter the interface. Addition, of 21 small -lg strands reduced weakly the rate of macroscopic phase separation, indicating that the strands entered the interface, but could not arrest coalescence. It follows that the stabilization of W/W emulsions by large protein aggregates is not significantly influenced by residual native proteins or small strands.…”