Fabrication and emulsifying properties of non-covalent complexes between soy protein isolate fibrils and soy soluble polysaccharides

2021 ◽  
Author(s):  
Hekai Zhao ◽  
Shengnan Wang ◽  
Guilan Zhao ◽  
Yangyang Li ◽  
Xiulin Liu ◽  
...  

Non-covalent complexes (SPIF/SSPS) between soy protein isolate fibrils (SPIF) and soy soluble polysaccharides (SSPS) were fabricated and used to stabilize oil-in-water (O/W) emulsions. FT-IR spectroscopy and zeta potential results demonstrated...

2017 ◽  
Vol 71 (11) ◽  
pp. 2437-2445 ◽  
Author(s):  
Zhiwei Yan ◽  
Qian Li ◽  
Pudun Zhang

It is a trend to substitute bioplastics for petroleum-based plastics in food packaging. Glycerol-plasticized soy protein isolate (SPI) is promising as a replacement for traditional petroleum-based plastics. Hydrogen bonding (H-bonding) plays a key role in plasticization of SPI film. However, few publications are concerned with the interactions of SPI and glycerol at the molecular level. In this paper, attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy was applied to investigate the effect of H-bonding on the secondary structures of glycerol-plasticized SPI films and thus on the plasticization. An “S” profile of the H-bonding between SPI and glycerol with an abrupt jump in the glycerol range of 10–30% was achieved. For more in-depth investigation of the H-bonding, two-dimensional correlation spectroscopy (2D-COS) and perturbation-correlation moving-window two-dimensional (PCMW2D) analyses were applied to the amide I and II bands of SPI films spectra series. The conformation change sequences under the effect of H-bonding were revealed. When glycerol was involved, it entered into the β-sheet and the H-bonds of the SPI peptide backbone (C = O···H–N–) were replaced by the new H-bonds between SPI and glycerol (C = O···H–O–). The transformations of parallel β-sheet to β-turn in the range of 0–20% and anti-parallel β-sheet to β-turn in the range of 20–35% were obtained. In the 35–60% concentration range, the β-sheet was first changed to a transition state conformation, then together with the β-turn, to the random coil. The 2D-COS results clearly suggest that the conformations of SPI gradually change from the ordered to the less ordered and disordered, which significantly improve the plasticity of SPI film.


Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 636 ◽  
Author(s):  
Marta Padial-Domínguez ◽  
F. Javier Espejo-Carpio ◽  
Raúl Pérez-Gálvez ◽  
Antonio Guadix ◽  
Emilia M. Guadix

The incorporation of lipid ingredients into food matrices presents a main drawback—their susceptibility to oxidation—which is associated with the loss of nutritional properties and the generation of undesirable flavors and odors. Oil-in-water emulsions are able to stabilize and protect lipid compounds from oxidation. Driven by consumers’ demand, the search for natural emulsifiers, such as proteins, is gaining much interest in food industries. This paper evaluates the in vitro emulsifying properties of protein hydrolysates from animal (whey protein concentrate) and vegetal origin (a soy protein isolate). By means of statistical modelling and bi-objective optimization, the experimental variables, namely, the protein source, enzyme (i.e., subtilisin, trypsin), degree of hydrolysis (2–14%) and emulsion pH (2–8), were optimized to obtain their maximal in vitro emulsifying properties. This procedure concluded that the emulsion prepared from the soy protein hydrolysate (degree of hydrolysis (DH) 6.5%, trypsin) at pH 8 presented an optimal combination of emulsifying properties (i.e., the emulsifying activity index and emulsifying stability index). For validation purposes, a fish oil-in-water emulsion was prepared under optimal conditions, evaluating its physical and oxidative stability for ten days of storage. This study confirmed that the use of soy protein hydrolysate as an emulsifier stabilized the droplet size distribution and retarded lipid oxidation within the storage period, compared to the use of a non-hydrolyzed soy protein isolate.


2021 ◽  
Vol 307 ◽  
pp. 110625
Author(s):  
Jinning Liu ◽  
Hualu Zhou ◽  
Yunbing Tan ◽  
Jorge L. Muriel Mundo ◽  
David Julian McClements

2021 ◽  
Author(s):  
Tu Tran

The stabilizing behaviour of soluble soy polysaccharide (SSPS) on acidified dispersions of soy protein isolate (SPI) and SPI-stabilized emulsions was studied. SPI and SSPS suspensions were characterized via light scattering, surface charge measurement, turbidity, sedimentation analysis, and light microscopy. At acidic pH (pH 6-3), it was found the addition of at least 0.25 wt% SSPS was required to stabilize 0.75 wt% SPI suspensions against aggregation and phase separation, likely via steric repulsion. The mechanism of SPI-SSPS interaction was shown to be electrostatic in nature by testing the effects of increased ionic strength of the suspensions. The stabilizing effect of SSPS on SPI was then applied to 5% oil-in-water emulsions. The presence of SSPS stabilized the emulsions against droplet size increases and phase separation over time. Overall, the results demonstrated that it was possible for SSPS to stabilize SPI suspensions and that SPI-SSPS interactions may be used as a tool to stabilize O/W emulsions.


2012 ◽  
Vol 602-604 ◽  
pp. 1206-1210
Author(s):  
Guo Ping Yu ◽  
Chao Ran Dou ◽  
Yan Song ◽  
Hao Wu ◽  
Zhu Gong

The objective of the study was to investigate the impact of soy protein isolate (SPI)-maltodextrin conjugates on the freeze-thaw stability of oil-in-water emulsions. Covalent coupling of maltodextrin to SPI was achieved by wet heating of SPI- maltodextrin mixtures of different weight ratios and different protein contents at 70,80,90,100°C for 1 to 5 h. The freeze-thaw stability was characterized by measurements of creaming index and oiling off after isothermal storage at -20 °C for 24 h and further thawing. Compared with those stabilized by SPI alone, o/w emulsions stabilized by SPI-maltodextrin conjugates showed a higher stability against freeze-thaw treatment, exhibiting a lower creaming index and oiling off.


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