Limited Aggregation Behavior of β-Conglycinin and Its Terminating Effect on Glycinin Aggregation during Heating at pH 7.0

Abstract

In this work, different thermal aggregation behaviors of soy β-conglycinin and glycinin at pH 7.0 were characterized with size exclusion chromatography and low-angle light scattering. Limited aggregation that grew via the consumption of "monomers" was detected in β-conglycinin, forming soluble aggregates. For glycinin, the association between the aggregates that led to the appearance of insoluble materials was observed. Heated with β-conglycinin, the assembly between the glycinin aggregates was terminated and its solubility was recovered. The structure of the soluble and insoluble aggregates was analyzed by small-angle X-ray scattering and dynamic light scattering. Unlike the β-conglycinin soluble aggregates that possessed limited size and less compact conformation, particles with a denser core and a less dense outer shell were found in the glycinin insoluble aggregates. Evidence is presented to reveal the transition between the soluble and insoluble aggregates and the role of β-conglycinin in the solubilization of the soy protein aggregates during heating.

Soy glycinin as food-grade Pickering stabilizers: Part. I. Structural characteristics, emulsifying properties and adsorption/arrangement at interface

“…100 C relative to 90 C). A similar observation about the influence of heating on the aggregation of SG has been observed by Guo et al (2012), which is well in accordance with the fact that the heating treatment at above the denaturation temperature of SG usually results in structural unfolding and subsequent aggregation of the molecules.…”

“…1B). The D z of particles for unheated SG solution is basically comparable to the observation (52 nm) using the same DLS by Guo et al (2012), and even that for native soy protein isolate (SPI) at comparable pH and ionic strength (about 58 nm; Liu & Tang, 2013). However, the magnitude of the D z is considerably higher than the expected size of the 11S form for SG (14.6 nm; Pizone Ruiz-Henestrosa, Martinez, Patino & Pilosof, 2012), thus indicating that most of SG components in the unheated solution were present in the nanoparticle aggregate form.…”

“…The observation showing occurrence of thermal aggregation is reasonably expected, since the heating was done above the denaturation temperature of SG, e.g. 76e84 C previously reported for dilute SG solution (0.5e1.0%, w/v) by Guo et al (2012) and Keerati-U-Rai and Corredig (2009).…”

Changes in the structure and dissociation of soybean protein isolate induced by ultrasound-assisted acid pretreatment

“…Li, Wang, Hu, and Liao (2014) reported that more intense high pressure CO 2 treatment caused the dissociation of larger aggregates and further aggregation in the smaller aggregates, which resulted in the change of polyphenol oxidase activity of thaumatin-like protein. The effect of heat_in-duced dissociation and aggregation on the functional properties of soy protein was also reported (Guo et al, 2012;Keerati-u-rai & Corredig, 2009). Both soy 7S and 11S globulin in their isolated form can aggregate on heating, the nature of which depends upon the precise conditions of protein concentration, pH and ionic strength (Li et al, 2007).…”

Characterization and Interfacial Behavior of Nanoparticles Prepared from Amphiphilic Hydrolysates of β-Conglycinin–Dextran Conjugates

“…R g characterizes the particle size or compactness, whereas I (0) is relevant to the molecular mass of the particle. 35 Both R g and I (0) of the control samples were lower than those of their nanoparticle samples as shown in Table 3, which indicated that hydrophobic interactions of the unfolded protein led to aggregation during the desolvation process for preparing nanoparticles. Furthermore, the R h values of the control samples were also lower than that of the nanoparticle samples.…”