scholarly journals Rheological and Solubility Properties of Soy Protein Isolate

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3015
Author(s):  
Timothy D. O′Flynn ◽  
Sean A. Hogan ◽  
David F. M. Daly ◽  
James A. O′Mahony ◽  
Noel A. McCarthy
Keyword(s):  
Heat Treatment ◽  
Soy Protein ◽  
Water Solubility ◽  
Protein Solubility ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Ph Values ◽  
Low Viscosity ◽  
Alkaline Conditions ◽  
Low Amplitude

Soy protein isolate (SPI) powders often have poor water solubility, particularly at pH values close to neutral, which is an attribute that is an issue for its incorporation into complex nutritional systems. Therefore, the objective of this study was to improve SPI solubility while maintaining low viscosity. Thus, the intention was to examine the solubility and rheological properties of a commercial SPI powder at pH values of 2.0, 6.9, and 9.0, and determine if heat treatment at acidic or alkaline conditions might positively influence protein solubility, once re-adjusted back to pH 6.9. Adjusting the pH of SPI dispersions from pH 6.9 to 2.0 or 9.0 led to an increase in protein solubility with a concomitant increase in viscosity at 20 °C. Meanwhile, heat treatment at 90 °C significantly improved the solubility at all pH values and resulted in a decrease in viscosity in samples heated at pH 9.0. All SPI dispersions measured under low-amplitude rheological conditions showed elastic-like behaviour (i.e., G′ > G″), indicating a weak “gel-like” structure at frequencies less than 10 Hz. In summary, the physical properties of SPI can be manipulated through heat treatment under acidic or alkaline conditions when the protein subunits are dissociated, before re-adjusting to pH 6.9.

scholarly journals Rheology and Water Absorption Properties of Alginate–Soy Protein Composites

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1807
Author(s):  
Estefanía Álvarez-Castillo ◽  
José Manuel Aguilar ◽  
Carlos Bengoechea ◽  
María Luisa López-Castejón ◽  
Antonio Guerrero
Keyword(s):  
Soy Protein ◽  
Water Solubility ◽  
Divalent Cations ◽  
Low Cost ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Guluronic Acid ◽  
Wide Range ◽  
Anionic Polysaccharides ◽  
Porous Matrices

Composite materials based on proteins and carbohydrates normally offer improved water solubility, biodegradability, and biocompatibility, which make them attractive for a wide range of applications. Soy protein isolate (SPI) has shown superabsorbent properties that are useful in fields such as agriculture. Alginate salts (ALG) are linear anionic polysaccharides obtained at a low cost from brown algae, displaying a good enough biocompatibility to be considered for medical applications. As alginates are quite hydrophilic, the exchange of ions from guluronic acid present in its molecular structure with divalent cations, particularly Ca2+, may induce its gelation, which would inhibit its solubilization in water. Both biopolymers SPI and ALG were used to produce composites through injection moulding using glycerol (Gly) as a plasticizer. Different biopolymer/plasticizer ratios were employed, and the SPI/ALG ratio within the biopolymer fraction was also varied. Furthermore, composites were immersed in different CaCl2 solutions to inhibit the amount of soluble matter loss and to enhance the mechanical properties of the resulting porous matrices. The main goal of the present work was the development and characterization of green porous matrices with inhibited solubility thanks to the gelation of alginate.

Influence of Thermal Treatment and Soy Bean Protein Characteristics on Muscle Protein Emulsion Stability

2006 ◽  
Vol 12 (3) ◽  
pp. 195-204 ◽  
Author(s):  
M. P. Rodríguez ◽  
C. Regue ◽  
A. Bonaldo ◽  
C. Carrara ◽  
L. G. Santiago
Keyword(s):  
Heat Treatment ◽  
Soy Protein ◽  
Emulsion Stability ◽  
Muscle Protein ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Stable Emulsion ◽  
Protein Isolates ◽  
Interfacial Film ◽  
Soy Protein Isolates

The effects of heat treatment on the interaction of salt soluble muscle protein and soy protein isolate in model emulsions were studied. Three soy protein isolates (SPI) were used: a commercial one (CSPI) and two pilot plant samples: a native soy protein isolate (NSPI) and an acid treated soy protein isolate (ASPI). Emulsions were prepared with muscle protein (MP), NSPI, ASPI, CSPI and mixtures of MP and the different SPIs, and then treated at 20, 55, 70, 80 and 90°C. Coalescence, soluble protein and electrophoresis of the aqueous phase of the emulsions were evaluated for each temperature. At 20°C the more native soy protein (NSPI) was compatible with MP, producing a stable emulsion that became more stable during heat treatment. CSPI alone could not form a stable interfacial film through the temperature range, however emulsion stabilisation was achieved at 55°C and 70°C when adding MP. Emulsions prepared with MP ASPI were highly unstable at 20°C, while as the emulsion temperature increased, coalescence decreased abruptly and maintained low values at every temperature. MP, NSPI, ASPI and MP NSPI produced stable emulsions both at 20°C and higher temperatures.

scholarly journals Double-Network Hydrogels of Corn Fiber Gum and Soy Protein Isolate: Effect of Biopolymer Constituents and pH Values on Textural Properties and Microstructures

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 356
Author(s):  
Jinxin Yan ◽  
Xin Jia ◽  
Wenjia Yan ◽  
Lijun Yin
Keyword(s):  
Soy Protein ◽  
Laser Scanning ◽  
Soy Protein Isolate ◽  
Textural Properties ◽  
Protein Isolate ◽  
Laser Scanning Microscopy ◽  
Corn Fiber ◽  
Confocal Laser ◽  
Double Network ◽  
Ph Values

Corn fiber gum (CFG) -soy protein isolate (SPI) double-network (DN) hydrogels were fabricated using laccase and a heat treatment process, in which CFG solution formed the first gel network via laccase oxidation, while SPI formed the second network through heating, as described in our previous research. The aim of this study was to investigate the influences of CFG/SPI constituents (CFG concentration 0–3%, w/v; SPI concentration 8–10%, w/v) and pH values (5.0–7.5) on the textural properties, microstructures and water-holding capacities (WHC) of the CFG-SPI DN hydrogels. Confocal Laser Scanning Microscopy (CLSM) results showed an apparent phase separation when the CFG concentration was above 1% (w/v). The textural characteristics and WHC of most DN hydrogels were enhanced with increasing concentrations of CFG and SPI. Scanning Electron Microscopy (SEM) observations revealed that the microstructures of DN hydrogels were converted from coarse and irregular to smooth and ordered as pH values increased from 5.0 to 7.5. Excellent textural properties and WHC were observed at pH 7.0. This study developed various CFG-SPI DN hydrogels with diverse textures and structures, governed by the concentrations of protein/polysaccharide and pH values, and also contributes to the understanding of gum–protein interactions in DN hydrogels obtained under different conditions.

Effects of pH on Properties of Soy Protein Isolate/Guar Gum Composite Films

2012 ◽  
Vol 503-504 ◽  
pp. 446-449 ◽  
Author(s):  
Chun Xia Sui ◽  
Lian Zhou Jiang ◽  
Guo Ping Yu
Keyword(s):  
Soy Protein ◽  
Water Solubility ◽  
Guar Gum ◽  
Soy Protein Isolate ◽  
Composite Films ◽  
Water Vapor Permeability ◽  
Composite Membranes ◽  
Surface Hydrophobicity ◽  
Protein Isolate ◽  
Vapor Permeability

The objective of this research was to investigate the effect of pH(7.0, 8.0, 9.0, 10.0) on the properties of soy protein isolate (SPI)/guar gum (GG)composite films casted with 0.2 %(w/v)guar gum polysaccharide, 5.0 %(w/v)SPI, 1.5 %(w/v)glycerol plasticizer, and 4:1(v/v) mixture of distilled water and anhydrous alcohol. Composite membranes from different pH conditions were evaluated from following aspects: tensile strength (TS), elongation at break (EB), water vapor permeability (WVP), water solubility (WS) and surface hydrophobicity(SH)

Effects of heat treatment and glucono-δ-lactone-induced acidification on characteristics of soy protein isolate

2009 ◽  
Vol 23 (2) ◽  
pp. 344-351 ◽  
Author(s):  
Lydia J. Campbell ◽  
Xin Gu ◽  
Susan J. Dewar ◽  
Stephen R. Euston
Keyword(s):  
Heat Treatment ◽  
Soy Protein ◽  
Soy Protein Isolate ◽  
Protein Isolate
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