scholarly journals Effect of Secondary Structure determined by FTIR Spectra on Surface Hydrophobicity of Soybean Protein Isolate

2011 ◽  
Vol 15 ◽  
pp. 4819-4827 ◽  
Author(s):  
Chen Wang ◽  
Lianzhou Jiang ◽  
Dongxu Wei ◽  
Yang Li ◽  
Xiaonan Sui ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Zhongjiang Wang ◽  
Yang Li ◽  
Lianzhou Jiang ◽  
Baokun Qi ◽  
Linyi Zhou

This study investigated relationship between secondary structure and surface hydrophobicity of soy protein isolate (SPI) subjected to a thermal treatment at 70~90°C. Heat denaturation increased the surface hydrophobicity and surface hydrophobicity decreased as aggregate formed. Heat caused an increase in the relative amount ofα-helix structures and an overall decrease in the amount ofβ-sheet structures when compared with nontreated SPI. The relative amounts of secondary structures varied with time, temperature, and intensity of heat treatment applied. Theβ-sheet structure was most important for its significant role in denaturation of 7S globulin and following formed aggregates and even in denaturation of 11S globulin. The amount ofβ-sheet structure in SPI had an inverse correlation with the surface hydrophobicity when the temperature was kept below 90°C. Besides,β-turn structure increased asβ-7S/B-11S aggregate formated.


2015 ◽  
Vol 1092-1093 ◽  
pp. 1525-1528
Author(s):  
Chao Zhang ◽  
Xiao Fei Guo ◽  
Yue Ma ◽  
Xiao Yan Zhao

The effect of the drying temperature on the secondary structure of the soybean protein-isolate/carboxymethyl cellulose/stearic acid composite films was evaluated. The Fourier transform-infrared spectra showed that the stearic acid lose some characteristic absorptions. Hence, the stearic acid was well integrated with the other ingredients. The absorption band (1600~1700 cm-1) of the composite film was deconvoluted into 9 peaks for the calculation of their secondary structure. The β-sheet content of the composite films dried at 90 oC was significant higher than that of the control. Hence, the composite films dried at 90 oC was more stable than the control.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2127 ◽  
Author(s):  
Yinglei Zhang ◽  
Yanyang Yin ◽  
Shuwen Lu ◽  
Xinmiao Yao ◽  
Xianzhe Zheng ◽  
...  

To explore better methods of natural protein modification for black soybean, comparisons among the effects of different modified methods on structural changes of the modified products of black soybean protein isolate (BSPI) were carried out in this study. The modified products used in this study included enzymatic crossing-link black soybean protein isolate (ECBSPI), wet heating treatment glycosylation black soybean protein isolate (WHTGBSPI) and especially enzymatic glycosylation black soybean protein isolate catalyzed by transglutaminase (EGBSPI). The effects of the modification methods on structural changes were analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), amino acid content and circular dichroism (CD) analysis. Moreover, the processing properties changes caused by structural changes of BSPI were detected by thermogravimetric analysis, particle size analysis, zeta-potential, surface hydrophobicity, solubility, emulsification, gelation, and rheological properties. The results show that the modified BSPI products were protein polymers, and among them, EGBSP and WHTGBSPI are covalently bonded glycation products. Products modified by Maillard reactions and transglutaminase (TG) display partly destroyed α-helix and β-sheet structures that form more open secondary BSPI structures. For ECBSPI, the proportion of irregular crimp structure reduces to form a high order secondary structure. All the modified products form fine aggregations in dispersion, except WHTGBSPI has most negative zeta-potential and least molecular stability due to the hydrophobic amino acids embedded in the protein molecules. The zeta-potentials of BSPI, ECBSPI, WHTGBSPI and EGBSPI are respectively −21.5, −23.8, −18.1 and −20.2 mV. The surface hydrophobicity of EGBSPI (5.07 ± 0.07) and WHTGBSPI (7.02 ± 0.05) decrease, while the surface hydrophobicity of ECBSPI (19.5 ± 0.06) increases. The solubility and rheological properties of EGBSPI, ECBSPI and WHTGBSPI after modification are all better than those of BSPI, especially EGBSPI. Emulsification of EGBSPI and WHTGBSPI increase (by 24.5% and 12.2%, respectively) while ECBSPI decrease (by 17.0), and there is similar emulsion stability trend. Moreover, the properties of ECBSPI increase except cohesiveness compared to BSPI. In conclusion, as a safe and efficient method for natural protein modification, enzymatic glycosylation catalyzed by TG has great potential in improving food processing characteristics.


2014 ◽  
Vol 240 (2) ◽  
pp. 367-378 ◽  
Author(s):  
Yujie Su ◽  
Yiting Dong ◽  
Fuge Niu ◽  
Chenying Wang ◽  
Yuntao Liu ◽  
...  

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4337 ◽  
Author(s):  
Li Tan ◽  
Pengzhi Hong ◽  
Ping Yang ◽  
Chunxia Zhou ◽  
Dinghao Xiao ◽  
...  

The secondary structure of a protein has been identified to be a crucial indicator that governs its water solubility. Tilapia protein isolate (TPI), soybean protein isolate (SPI), and tilapia-soybean protein co-precipitates (TSPC3:1, TSPC2:1, TSPC1:1, TSPC1:2, and TSPC1:3) were prepared by mixing tilapia meat and soybean meal at different mass ratios. The results demonstrated that the water solubility of TSPCs was significantly greater than that of TPI (p <0.05). The changes in ultraviolet–visible and near-ultraviolet circular dichroism spectra indicated that the local structure of TSPCs was different from that of TPI and SPI. Fourier transform infrared Spectroscopy revealed the co-existence of TPI and SPI structures in TSPCs. The secondary structures of TSPCs were predominantly α-helix and β-sheet. TSPC1:1 was unique compared to the other TSPCs. In addition, there was a good correlation between the water solubility and secondary structure of TSPCs, in which the correlation coefficients of α-helix and β-sheet were −0.964 (p <0.01) and 0.743, respectively. TSPCs displayed lower α-helix contents and higher β-sheet contents compared to TPI, which resulted in a significant increase in their water solubility. Our findings could provide insight into the structure–function relationship of food proteins, thus creating more opportunities to develop innovative applications for mixed proteins.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 667
Author(s):  
Chenxiao Wang ◽  
Hao Yin ◽  
Yanyun Zhao ◽  
Yan Zheng ◽  
Xuebing Xu ◽  
...  

This work aimed to improve the functional properties of soybean protein isolate (SPI) by high hydrostatic pressure (HHP) and develop SPI incorporated yogurt. Response surface methodology (RSM) was used to optimize the HHP treatment parameters, including pressure, holding time, and the ratio of SPI/water. Water holding capacity, emulsifying activity index, solubility, and hardness of SPI gels were evaluated as response variables. The optimized HPP treatment conditions were 281 MPa of pressure, 18.92 min of holding time, and 1:8.33 of SPI/water ratio. Water and oil holding capacity, emulsifying activity, and stability of SPI at different pH were improved. Additionally, relative lipoxygenase (LOX) activity of HHP treated SPI (HHP-SPI) was decreased 67.55 ± 5.73%, but sulphydryl group content of HHP-SPI was increased 12.77%, respectively. When incorporating 8% of SPI and HHP-SPI into yogurt, the water holding capacity and rheological properties of yogurt were improved in comparison with yogurt made of milk powders. Moreover, HHP-SPI incorporated yogurt appeared better color and flavor.


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