Structural and Functional Changes in Ultrasonicated Oyster Protein Isolates

2019 ◽  
Vol 15 (3-4) ◽  
Author(s):  
Cuiping Yu ◽  
Fan Wu ◽  
Yue Cha ◽  
Henan Zou ◽  
Yingnan Guo ◽  
...  

AbstractStructural and functional changes in ultrasonicated oyster protein isolates (OPI) were investigated. Ultrasound treatments were carried out with probe (20 kHz) at 200, 400 and 600 W for 15 and 30 min. The results showed that functional properties of OPI significantly improved after sonication. Absolute zeta potential and protein solubility increased by 18.40 mV and 82.5 % at 600 W for 15 min. Oil holding capacity, emulsifying activity index, emulsion stability index, foaming ability and foaming stability increased by 300 %, 15.23 m2/g, 9.24 min, 23.9 % and 14.8 % at 600 W for 30 min. However, ultrasound treatment significantly (P < 0.05) decreased particle size and water holding capacity. The conformation of OPI became stretched and unfolded after sonication. Functional improvements resulted from stretched and unfolded conformation and reduction of particle size. Controlled condition of ultrasound can produce OPI with distinct structural and functional properties, which could meet the complex needs of manufactured food products in food industry, but further study is needed to understand the specific mechanism.

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3265 ◽  
Author(s):  
Wenjun Ma ◽  
Fengying Xie ◽  
Shuang Zhang ◽  
Huan Wang ◽  
Miao Hu ◽  
...  

The soy protein isolates (SPI) extracted from different extruded full-fat soybean flakes (FFSF), and their conformational and functional properties were characterized. Overall, the free thiol (SH) content of SPI increased when the extrusion temperature was below 80 °C and decreased at higher temperatures. Soy glycinin (11S) showed higher stability than β-conglycinin (7S) during extrusion. Results also indicated that the increase in some hydrophobic groups was due to the movement of hydrophobic groups from the interior to the surface of the SPI molecules at extrusion temperatures from 60 to 80 °C. However, the aggregation of SPI molecules occurred at extrusion temperatures of 90 and 100 °C, with decreasing levels of hydrophobic groups. The extrusion temperature negatively affected the emulsifying activity index (EAI); on the other side, it positively affected the emulsifying stability index (ESI), compared to unextruded SPI.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Na Thi Ty Ngo ◽  
Fereidoon Shahidi

AbstractCamelina and flixweed (sophia) seed protein isolates were prepared using both the conventional extraction and ultrasonic-assisted extraction methods at 40 kHz for 20 min, and their functional properties investigated. SDS-PAGE showed that both ultrasound-assisted and conventional extractions resulted in a similar protein profile of the extract. The application of ultrasound significantly improved protein extraction/content and functional properties (water holding capacity, oil absorption capacity, emulsifying foaming properties, and protein solubility) of camelina protein isolate and sophia protein isolate. The water-holding and oil absorption capacities of sophia protein isolate were markedly higher than those of camelina protein isolate. These results suggest that camelina protein isolate and sophia protein isolate may serve as natural functional ingredients in the food industry. Graphical Abstract


2019 ◽  
pp. 1-12
Author(s):  
Haq Nawaz ◽  
Muhammad Aslam Shad ◽  
Sonia Sonia Safdar ◽  
Raheela Jabeen

The effect of particle size and high dose gamma irradiation on functional properties of maize flour was studied. The maize flour at three levels of particle size (-177, -250 and -420 µm obtained from sieves of 80, 60 and 40 meshes respectively) was irradiated in transparent glass bottles at three levels of gamma radiation (25, 50 and 75 kGy) using 60Co gamma source. A significant linear increase in water holding and swelling capacities and bulk density values and significant linear decrease in emulsifying stability was observed in response to an increase in particle size of the flour. Gamma radiation dose was found to show a significant linear positive effect on water holding capacity and solubility but a significant linear negative effect on oil holding capacity, protein solubility and bulk density values. These observed trends in functional properties of maize flour with the application of gamma irradiation suggests that quality of maize flour, regarding the manufacture and packaging of food products, may be improved by irradiation process.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Antonio Hilario Lara-Rivera ◽  
Pedro García-Alamilla ◽  
Laura Mercedes Lagunes-Gálvez ◽  
Ramón Rodríguez Macias ◽  
Pedro M. García López ◽  
...  

Protein isolates prepared by alkaline solubilization followed by isoelectric precipitation and freeze-drying from six varieties of Lupinus angustifolius (Haags Blaue, Sonate, Probor, Borlu, Boregine, and Boruta) grown in Mexico were evaluated for functional properties: nitrogen solubility, water-holding capacity (WHC), oil holding capacity (OHC), emulsion activity index (EAI), emulsion stability index (ESI), foaming capacity (FC), foam stability (FS), and gelling minimum concentration (GMC). The nitrogen solubility values, WHC, OHC, and FC did not show significant differences between the protein isolates. The solubility of the isolates was minimal at pH of 4.0 and 5.0 while the regions of maximum solubility were found at pH of 2.0 and 10.0. There were significant differences in EAI and ESI depending on the varieties used. The isolates of the Boregine and Borlu varieties showed the highest EAI with 29.3 and 28.3 m2 g−1, respectively, while the lowest index was recorded in the isolate obtained from the Sonate variety (24.6 m2 g−1). Like solubility, these indices also increased at both extremes of pH evaluated; both properties were minimal in the isoelectric pH range (4.0 to 5.0).


2015 ◽  
Vol 1 (2) ◽  
pp. 67
Author(s):  
Haq Nawaz ◽  
Muhammad Aslam Shad ◽  
Rabia Mehmood ◽  
Tanzila Rehman ◽  
Hira Munir

<p>Functional properties such as protein solubility, swelling capacity, water holding capacity, gelling ability, bulk density and foaming capacity of flours of some commonly used cereals and legume (wheat, refined wheat, maize and chickpea) and their blends were studied. Blends of flours were prepared by mixing equal proportions of selected floors. Statistically significant difference  in studied functional properties except bulk density was observed among cereal flours and their blends. Chickpea flour was found to possess comparatively high water holding capacity, protein solubility index and swelling capacity. The functional properties of maize and wheat flours were found to be improved when blended with chickpea. Chickpea flour and its blends with cereal flours were found to possess good functional score and suggested as favorable candidates for use in the preparation of viscous foods and bakery products. The data provide guidelines regarding the improvement in functional properties of economically favorable cereal flours.<strong></strong></p>


2016 ◽  
Vol 33 (No. 5) ◽  
pp. 474-479 ◽  
Author(s):  
J. Ren ◽  
Ch. Song ◽  
P. Wang ◽  
S. Li ◽  
N. Kopparapu ◽  
...  

The structural and functional properties such as solubility, emulsifying properties, foaming properties, oil binding capacity, and surface hydrophobicity of sunflower 11S globulin hydrolysates generated by Alcalase at hydrolysis time of 30, 60, 90, and 120 min were evaluated. Circular dichroism analysis showed the hydrolysates possessed a decreased α-helix and β-structure. The hydrolysates exhibited lower surface hydrophobicity. Hydrolysates with shorter hydrolysis time showed the higher emulsifying activity index, but the same emulsion stability and oil binding capacity compared to the original 11S globulin. The longer hydrolysis resulted in lower foaming and emulsion stability. Thus it was demonstrated that by controlling the hydrolysis time of sunflower 11S globulin, hydrolysate with a desirable functional properties can be obtained.


2015 ◽  
Vol 3 (5) ◽  
pp. 712-715 ◽  
Author(s):  
Tatsuya Murakami ◽  
Haruki Okamoto ◽  
Hyungjin Kim

The timing of TRITC–apoA-I conjugation significantly influences the structural and functional properties of reconstituted HDL particles.


2011 ◽  
Vol 29 (No. 2) ◽  
pp. 129-136 ◽  
Author(s):  
L. Mu ◽  
H. Zhao ◽  
M. Zhao ◽  
Ch. Cui ◽  
L. Liu

Protein-polysaccharide conjugates were generally prepared by dry-heating. However, it was time-consuming and the sample gained was inhomogeneous. A faster way of preparing protein-polysaccharide conjugates is needed. Accordingly, soy protein isolates (SPI)-Acacia gum (GA) conjugates prepared by the wet-heating method were studied in the present work. Physicochemical properties of SPI-GA conjugates were also determined. The results showed that the wet-heating method could improve the rate of the graft reaction of protein and polysaccharide. The solubility of SPI-GA conjugates was significantly (P &lt; 0.05) higher than that of unreacted SPI-GA mixtures and SPI at the same pH values. The emulsion activity index (EAI) of the grafted SPI increased remarkably. Moreover, a significant (P &lt; 0.05) improvement on the emulsifying stability index (ESI) was observed and emulsions with a smaller droplet size were obtained. No visible flocculation during extended storage (30 days) was observed. The time course of the development of the graft reaction of SPI with GA was also shown by SDS-PAGE.


2009 ◽  
Vol 52 (6) ◽  
pp. 1555-1562 ◽  
Author(s):  
Cristina Moreira da Silveira ◽  
Eliana Badiale-Furlong

Functional properties of fermented bran produced by Aspergillus oryzae and Rhizopus sp. in a solid-state fermentation system were determined, with an aim to evaluate their application in food formulation. The defatted rice bran and wheat bran were inoculated with the spores of the cultures and incubated at 30º C for 72 h. Samples were withdrawn at 0, 24, 48 and 72 h. Protein content, protein solubility, in-vitro digestibility, gelation and water holding capacity were determined in bran with or without fermentation. Rhizopus sp. increased significantly the protein content (69.0 and 56.0%, respectively, for defatted rice bran and wheat bran); protein solubility (28.5 and 36.2) and water holding capacity (11.4% for wheat bran). When A. oryzae was used all these properties were modified significantly after fermentation.


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