Soy Protein Particles

Adsorption to casein particles below pH 4.2. Adsorption to soy protein particles below pH 4.8. 

Figure 1. Plot of change in aggregate volume vs. aggregate size for given time interval during breakup of isoelectrically precipitated soy protein. Particle volume fraction, 0.00531. Shear rate, 1010 s-- -.

Petanate, A.M. and Glatz, C.E., 1983. Isoelectric precipitation of soy protein. I. Factors affecting particle size distributions. II. Kinetics of protein aggregate growth and breakage. Biotechnology and Bioengineering, 25, 3049. 

The binders vary quite widely—the most common being starch, soy protein and latexes in conjunction with other soluble polymers. Styrene-butadiene latexes have been the most popular but ethylene-vinyl acetate binders are also used. The method of polymer synthesis provides a way of modifying the properties of the latex. For example, adjustment of the ratio of styrene butadiene in the co-polymer gives rise to different degrees of softness or hardness. This property has a profound influence on the quality of the coating. It is also possible to co-polymerise monomers so as to introduce, for example, carboxy groups on to the surface of the latex particle which in turn assist in... 

However, studies in hypercholesterolemic subjects, using soy protein depleted of isoflavones have shown that soy protein independently of isoflavones can favorably affect LDL size, LDL particle distribution was shifted to a less atherogenic pattern,and can decrease triglyceride concentrations, triglyceride fatty acid fractional synthesis rate, and cholesterol... 

In line with the general increase in thermodynamic affinity of surfactant-protein particles for the aqueous medium, a marked increase in the solubility of soy protein has been observed in response to interactions with SDS (Malhotra and Coupland, 2004). In contrast, however, the self-assembly of the globular protein legumin, as modified by the anionic... 

Hence the stronger the dependence of nucleation on supersaturation, the greater will be the increase in number of primary particles as initial supersaturation increases. For (3m-l)/5 > 1 (i.e. m > 2), the size of those particles will decrease with initial supersaturation. No dependence on mixing conditions appears the concentration dependence for soy protein precipitates (via hydrochloric acid addition) was found (4 ) to be... 

Figure 2. Particle (number) size distributions for isoelectrically precipitated soy protein showing the effects of shear rate and protein concentration. Points are experimental data curves are the model fit using Equation 12. Shear rates A, 417 s l ...

With a typical size ranging from nanometric (<100 nm) to submicrometric (<1 pm), biopolymeric particles and nanoparticles, made of proteins or polysaccharides, thanks to their excellent compatibility with foods, are able to efficiently encapsulate, protect and deliver bioactive compounds, forming different structures, such as random coils, sheets, or rods around the bioactive molecules. The most suitable biopolymers for the incorporation into foods include (1) proteins, such as whey proteins, casein, gelatin, soy protein, zein, and (2) polysaccharides, such as starch, cellulose, and other hydrocolloids, with the particle formulation depending on the desired particle functionality (size, morphology, charge, permeability, environmental stability), on end product compatibility and in general in product behavior, as well as on release properties and in body behavior. 

The homogeneous dispersion of cellulose nanoparticles in a polymer matrix in order to obtain nanomaterials is due to their size, which allows penetration in hydrosoluble or at least hydrodispersible structures (as latex-form polymers) as well as dispersion of polysaccharide nanocrystals in nonaqueous media especially using surfactants and chemical grafting. Thus, one of the processing techniques of polymer nanocomposites reinforced with polysaccharide nanocrystals was carried out using hydrosoluble or hydrodispersible polymers. In this respect, the literature has reported preparation of polysaccharide particles with reinforced starch (Svagan et al. 2009), silk fibroin (Noishiki et al. 2002), poly(oxyethylene) (POE) (Samir et al. 2006), polyvinyl alcohol (PVA) (Zimmermann et al. 2005), hydroxypropyl cellulose (HPC) (Zimmermann et al. 2005), carboxymethyl cellulose (CMC) (Choi and Simonsen 2006), or soy protein isolate (SPI) (Zheng et al. 2009). 

Soy protein, with proper processing, enjoys several advantages such as the ability to form a network structure for use as resin [67]. It can be processed into films for use as garbage and grocery bags [68], edible films [69,70] and adhesives in particle board and plywood [71, 72], Soy protein resin has also been combined with natural fibers to produce reinforced composites [19-24, 35, 36]. Some of these efforts are described later in this chapter. 

Effect of modification of fillers on the thermal properties of soy protein composites was studied by Wang et al. (2013). They prepared edible films containing different ratios of SPI with wheat-bran cellulose (WC), microcrystaUine wheat-bran cellulose (MWC), and ultrasonic/microwave-modilied MWC (MMWC) by casting and thermal properties of the films were analyzed. It was found that different proportions and particle size of the fillers (WC, MWC, and MMWC) affected the thermal properties of each of the films. The SPI/MMWC film demonstrated the best... 

Fluidized bed powders and small particles milk powder, whey, yeast, casein, extruded food, coffee beans, soy beans, sunflower beans, chocolate granules, lactose, L-lysine, nutmeg, tomato powder, soy proteins, salt, sugar, and so on. 

For values of / = 2 and yS = 2.3 found to be reasonable, Glatz et al. (1967) have solved this equation numerically for various values of the parameters k and Ko, and compared the results with those obtained from soy-protein precipitation to select those values of k y) and Ko which provided agreement. Their model predicted that smaller particles are obtained at larger y and further that higher suspension densities led to larger aggregate sizes. 

Huang X, Netravali A. 2007. Characterization of Flax Fiber Reinforced Soy Protein Resin Based Green Composites Modified with Nano-Clay Particles. Composites Science and Technology... 

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