Emulsifying Properties and Oil/Water (O/W) Interface Adsorption Behavior of Heated Soy Proteins: Effects of Heating Concentration, Homogenizer Rotating Speed, and Salt Addition Level

Abstract

The adsorption of heat-denatured soy proteins at the oil/water (O/W) interface during emulsification was studied. Protein samples were prepared by heating protein solutions at concentrations of 1-5% (w/v) and were then diluted to 0.3% (w/v). The results showed that soy proteins that had been heated at higher concentrations generated smaller droplet size of emulsion. Increase in homogenizer rotating speed resulted in higher protein adsorption percentages and lower surface loads at the O/W interface. Surface loads for both unheated and heated soy proteins were linearly correlated with the unadsorbed proteins' equilibrium concentration at various rotating speeds. With the rise in NaCl addition level, protein adsorption percentage and surface loads of emulsions increased, whereas lower droplet sizes were obtained at the ionic strength of 0.1 M. The aggregates and non-aggregates displayed different adsorption behaviors when rotating speed or NaCl concentration was varied.

S/O/W emulsions prepared with sugar beet pectin to enhance the viability of probiotic Lactobacillus salivarius NRRL B-30514

“…The G s values in the present study were much higher (up to 40 mg/m 2 when the emulsion was prepared with 4% SBP at the O:W volume ratio of 1:8) than the 1e3 mg/m 2 expected for protein monolayers (Dickinson, 1997). A G s value of 9.16 mg/m 2 was reported for soybean oil emulsified by preheated soy protein that formed protein aggregates (Cui, Chen, Kong, Zhang, & Hua, 2014). The relatively high G s in the present study possibly is because SBP has a small fraction of protein and the glycated polysaccharide chains increase the molar mass of polymeric surfactants adsorbing on oil droplets (Leroux et al, 2003).…”

Effect of maleylation on physicochemical and functional properties of rapeseed protein isolate

“…Protein surface load (Γ s ), expressed as mg protein per m 2 fat surface area, was calculated by relating the adsorbed protein to the specific surface area of the emulsion (Cui et al 2014;Tsoukala et al 2006). Freshly prepared emulsions (as described earlier) were centrifuged for 30 min at 4293 × g (4°C) to accelerate creaming, and the lower serum (aqueous) phase (unadsorbed protein) was withdrawn carefully using a syringe.…”

Salting-out and salting-in: competitive effects of salt on the aggregation behavior of soy protein particles and their emulsifying properties

“…[1][2][3][4][5][6] However, as heat treatment to ensure microbiological safety is very common for food products during their processing, it is likely that a fraction of the SPI no longer exists in the native state, but present in an aggregated state with the formation of colloidal particles. The interfacial and emulsifying properties of SPIs have been widely tested on native proteins at varying protein concentration, temperature, pH and ionic strength.…”