Diverse rheological properties, mechanical characteristics and microstructures of corn fiber gum/soy protein isolate hydrogels prepared by laccase and heat treatment

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.

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Rheological properties of soy protein isolate – carboxymethyl flaxseed gum mixed dispersions under large amplitude oscillatory shear

International Journal of Food Engineering ◽

10.1515/ijfe-2018-0351 ◽

2020 ◽

Vol 16 (7) ◽

Author(s):

Yu-xi Ma ◽

Jin-lei Niu ◽

Dong Li ◽

Li-jun Wang

Keyword(s):

Rheological Properties ◽

Soy Protein ◽

Large Amplitude ◽

Soy Protein Isolate ◽

Shear Thickening ◽

Shear Thinning ◽

Protein Isolate ◽

Oscillatory Shear ◽

Large Amplitude Oscillatory Shear ◽

Flaxseed Gum

AbstractCarboxymethyl flaxseed gum (CMFG) is developed in our laboratory by modifying flaxseed gun through carboxymethylation. The aim of this study is to reveal the rheological properties of soy protein isolate – carboxymethyl flaxseed gum (SPI-CMFG) mixed dispersion in realistic processing conditions by conducting large amplitude oscillatory shear (LAOS) test, with consideration of concentration and degree of substitution (DS) of CMFG. Results showed that increasing CMFG concentration significantly increased storage moduli (Gʹ), loss moduli (Gʺ), and the apparent viscosity of all SPI-CMFG mixed dispersions. LAOS test illustrated that the dispersions experienced a transition from LAOS type IV to type III after increasing the concentration of CMFG, while the behavior converted from LAOS type I to type III by increasing DS. Fourier transform rheology (FTR) exhibited that increasing the concentration or DS of CMFG both induced a conversion from “soft sphere” to “hard sphere” behavior. The strain-stiffening ratio S and the shear-thickening ratio T demonstrated, that all SPI-CMFG dispersions experienced a similar conversion from strain stiffening to strain softening, and from shear thinning to shear thickening behaviors by increasing the concentration of CMFG. Nevertheless, the mixed dispersions presented shear thickening behaviors when DS was no more than 0.520 in the whole range of strain, while a conversion from shear thinning to shear thickening behavior occurred, when DS reached at 0.755 and 0.973.

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

Foods ◽

10.3390/foods10020356 ◽

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.

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