scholarly journals The Molecular Properties of Peanut Protein: Impact of Temperature, Relative Humidity and Vacuum Packaging during Storage

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2618 ◽  
Author(s):  
Xiaotong Sun ◽  
Hua Jin ◽  
Yangyang Li ◽  
Haiying Feng ◽  
Chunhong Liu ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Functional Properties ◽  
Surface Hydrophobicity ◽  
Protein Isolate ◽  
Peanut Protein ◽  
Molecular Properties ◽  
Random Coil ◽  
Bivariate Correlation ◽  
Protein Particle ◽  
Α Helix

This study aimed to investigate the variation of molecular functional properties of peanut protein isolate (PPI) over the storage process and reveal the correlation between the PPI secondary structure and properties in the storage procedure. After storage, the molecular properties of PPI changed significantly (p < 0.05). Extending storage time resulted in a decrease in free sulfhydryl content, fluorescence intensity, surface hydrophobicity and emulsifying properties, which was accompanied by an increase in protein particle size. The results of infrared spectroscopy suggested the content decline of α-helix and β-sheet, and the content rise of β-turn and random coil. Based on bivariate correlation analysis, it was revealed that surface hydrophobicity and emulsifying activity of PPI was significantly affected by α-helix and by β-turn (p < 0.05), respectively. This research supplied more information for the relationship between the peanut protein’s secondary structure and functional properties over the stored process.

Effects of High-Pressure Homogenization at Different Pressures on Structure and Functional Properties of Oyster Protein Isolates

2018 ◽  
Vol 14 (4) ◽  
Author(s):  
Cuiping Yu ◽  
Fan Wu ◽  
Yue Cha ◽  
Yuting Qin ◽  
Ming Du
Keyword(s):  
Particle Size ◽  
High Pressure ◽  
Secondary Structure ◽  
Zeta Potential ◽  
Functional Properties ◽  
Surface Hydrophobicity ◽  
Random Coil ◽  
Foaming Properties ◽  
High Pressure Homogenization ◽  
Protein Profiles

Abstract Oyster protein isolate (OPI) suspensions (6.19 % ± 0.82 %, w/v) were treated by high-pressure homogenization (HPH) at 0 (control), 20, 40, 60, 80 or 100 MPa for three cycles. Protein profiles, secondary structure, free sulfhydryl, surface hydrophobicity, particle size distribution, zeta-potential, solubility, water and oil holding capacity (OHC), emulsifying and foaming properties of the obtained suspensions were analyzed. The results showed that HPH treatment did not cause changes in protein profiles of OPI, but caused changes in secondary structure, content of α-helix decreased but content of β-turn and random coil increased significantly (P < 0.05). Free sulfhydryl and surface hydrophobicity all increased significantly (P < 0.05) after HPH treatment, indicating that tertiary and quaternary structures changed. Functional properties of OPI significantly (P < 0.05) improved after HPH treatment, such as zeta-potential (from −12.67 to −33.57 mV), solubility (from 20.24 % to 57.99 %), OHC (from 981.77 % to 1229.40 %), foaming ability (from 17.50 % to 35.00 %), foaming stability (from 44.49 % to 66.60 %), emulsifying activity index (from 8.87 to 17.06 m2/g) and emulsion stability index (from 14.65 to 41.68 min). At 60 MPa and 80 MPa, the improvements were more remarkable. However, HPH treatment significantly (P < 0.05) decreased particle size (from 200–500 nm to 0–200 nm) and water holding capacity (from 341.15 % to 216.96 %). These improvements were closely related to structural changes and reduction of particle size. Application of different pressures affected functional properties of OPI. These results could provide information for determining HPH applying condition in OPI modification.

scholarly journals Physicochemical Properties and Storage Stability of Food Protein-Stabilized Nanoemulsions

Nanomaterials ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 25 ◽  
Author(s):  
Yangyang Li ◽  
Hua Jin ◽  
Xiaotong Sun ◽  
Jingying Sun ◽  
Chang Liu ◽  
...  
Keyword(s):  
Corn Oil ◽  
Soybean Protein ◽  
Droplet Diameter ◽  
Protein Isolate ◽  
Random Coil ◽  
Food Protein ◽  
Soybean Protein Isolate ◽  
Bivariate Correlation ◽  
The Mean ◽  
Α Helix

This study investigated the preparation and properties of corn oil nanoemulsions stabilized by peanut protein isolate (PPI), rice bran protein isolate (RBPI), soybean protein isolate (SPI), and whey protein isolate (WPI). The mean droplet diameter of four protein-stabilized nanoemulsions prepared via ultrasound method was less than 245 nm. PPI-stabilized nanoemulsions showed better stability for 4 weeks, while the mean droplet diameter of RBPI-stabilized nanoemulsions had exceeded 1000 nm during the third week of storage. Fourier transform infrared and interfacial tension (IT) analysis showed that the higher level of disordered structure and lower IT of proteins made the stability of nanoemulsions better. Moreover, bivariate correlation analysis discovered that α-helix (p < 0.01) and β-turn (p < 0.05) of proteins were related to the mean droplet diameter of nanoemulsions, the random coil (p < 0.05) was related to the zeta potential of nanoemulsions. This study provided new idea for the relationship between the structure of protein and properties of protein-stabilized nanoemulsions.

scholarly journals Effect of Oxidation on Quality of Chiba Tofu Produced by Soy Isolate Protein When Subjected to Storage

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1877
Author(s):  
Yue Xu ◽  
Zhongjiang Wang ◽  
Baokun Qi ◽  
Anqi Ran ◽  
Zengwang Guo ◽  
...  
Keyword(s):  
Loss Modulus ◽  
Structural Characteristics ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Sensory Properties ◽  
Random Coil ◽  
Carbonyl Content ◽  
New Type ◽  
Α Helix

Chiba tofu is a new type of vegetarian food prepared with soy protein isolate (SPI). According to factory feedback, the SPI stored in the factory storeroom in summer undergoes reactive oxidation, which changes the structure of SPI and further affects the quality of Chiba tofu. Consequently, the main objective of this study was to prepare Chiba tofu with SPI with different storage periods and evaluate the effect of different degrees of oxidation on structural characteristics of SPI and rheology, texture, microstructure and sensory properties of Chiba tofu. The carbonyl content and turbidity of SPI significantly increased, and the contents of free sulfhydryl (SH) and disulfide bond (S-S) simultaneously decreased with storage time. The oxidation changes the SPI conformation, leading to a transition of α-helix and β-turn to β-sheet and random coil during the storage periods. In the SDS–PAGE analysis, oxidation promoted the SPI molecules crosslinked and aggregated, which affected the quality of Chiba tofu. In short storage periods (0–12 days), SPI was relatively moderately oxidized when the carbonyl content was between 4.14 and 6.87 mmol/g. The storage and loss modulus of Chiba tofu both increased, the network was compact, and the hardness and springiness of Chiba tofu showed an increasing trend. Moreover, in longer storage periods (12–30 days), the SPI was relatively severely oxidized when the carbonyl content was between 7.24 and 9.14 mmol/g, which had an adverse effect on Chiba tofu rheological and texture properties, microstructure, and sensory properties. In sensory evaluation, Chiba tofu stored 12 days had the highest overall quality score than that stored on other days. This study is expected to provide an argument for the better industrial production of Chiba tofu.

scholarly journals Secondary Structure of Bovine Albumin as Studied by Polarization-Sensitive Multiplex CARS Spectroscopy

1996 ◽  
Vol 50 (1) ◽  
pp. 78-85 ◽  
Author(s):  
Artemy Voroshilov ◽  
Cees Otto ◽  
Jan Greve
Keyword(s):  
Secondary Structure ◽  
Raman Spectra ◽  
Random Coil ◽  
Background Suppression ◽  
Good Correspondence ◽  
Bovine Albumin ◽  
Suppression Technique ◽  
Polarized Raman ◽  
Α Helix ◽  
Anti Stokes

The first application of polarization-sensitive multiplex coherent anti-Stokes Raman spectroscopy (MCARS) in the absence of resonance enhancement to the resolution of the secondary structure of a protein in solution is reported. Polarization MCARS spectra of bovine albumin in D2O were obtained in the range 1370 to 1730 cm−1 with the aid of the background suppression technique. The spectra were fitted simultaneously with a single set of parameters (band positions, bandwidths, amplitudes, and depolarization ratios). Polarized Raman spectra simulated with these parameters revealed a good correspondence with the spontaneous Raman spectra measured. The broad amide I′ band was decomposed assuming the three major secondary conformations of protein, of which the contribution of β-sheet structure was found to be negligible. Relative weights of α-helix and random coil conformations agree well with the estimates obtained with Raman and circular dichroism (CD) spectroscopies.

scholarly journals Clustering and Differentiation of glr-3 Gene Function and Its Homologous Proteins

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Yue Ma ◽  
Tiantian Guo ◽  
Yihe Wang ◽  
Xinna Li ◽  
Jingyu Zhang
Keyword(s):  
Secondary Structure ◽  
Protein Glycosylation ◽  
Random Coil ◽  
Homologous Gene ◽  
Phosphorylation Sites ◽  
Homologous Proteins ◽  
Homologous Genes ◽  
Glycosylation Sites ◽  
Α Helix ◽  
Cold Sensing

In order to adapt to the low temperature environment, organisms transmitexcitement to the central system through the thermal sensing system, whichis a classic reflex reaction. The cold receptor GLR-3 perceives cold and produces cold avoidance behavior through peripheral sensory neurons ASER.In order to further understand the gene encoding of the cold sensing glr-3gene and the evolution of its homologous gene group function and proteinfunction, the nucleotide sequence and amino acid sequence of the glr-3gene and its homologous gene in 24 species were obtained and compared.By clustering with the GRIK2 gene sequence of Rana chensinensis, the bioinformatics method was used to predict and sequence analyze the change ofgene, evolution rate, physical and chemical properties of protein, glycosylation sites, phosphorylation sites, secondary structure and tertiary structureof protein. The analysis results show that the glr-3 gene and its homologousgene have obvious positive selection effect. The protein prediction analysisshowed that the glr-3 gene and its homologous genes encoded proteinsin these 25 species were hydrophilic proteins, and the proportion of sidechains of aliphatic amino acids was high. The transmembrane helix waswidespread and there were more N-glycosylation sites and O-glycosylationsites. The protein phosphorylation sites encoded were serine, threonine andtyrosine phosphorylation sites. Secondary structure prediction showed thatthe secondary structure units of the encoded protein were α-helix, β-turn,random coil and extended chain, and the proportion of α-helix was the largest. This study provides useful information on the evolution and function ofthe cold sensing gene glr-3 and its homologous genes.

High-Pressure FTIR Studies of the Secondary Structure of Proteins

1996 ◽  
Author(s):  
Yoshihiro Taniguchi ◽  
Naohiro Takeda
Keyword(s):  
High Pressure ◽  
Secondary Structure ◽  
Cytochrome C ◽  
Ribonuclease A ◽  
Random Coil ◽  
Absorbance Spectroscopy ◽  
Α Helix ◽  
Bovine Pancreas ◽  
Β Sheet ◽  
Denaturation Of Proteins

Infrared spectra of five globular proteins (bovine pancreas ribonuclease A, horse skeletal muscle myoglobin, bovine pancreas insulin, horse heart cytochrome c, egg white lysozyme) in 5% D2O solutions (pD 7.0) were measured as a function of pressure up to 1470 MPa at 30 °C. According to the second-derivative spectral changes in the observed amide I band of the proteins, which indicate that the α-helix and β-sheet substructures of the secondary structures break dramatically into the random coil conformation, ribonuclease A and myoglobin are denatured reversibly at 850 MPa and 350 MPa, respectively. Lysozyme denatures partially and reversibly at 670 MPa, as shown by decrease in the α-helix and β-turn substructures, but no change occurs in the random coil and β-sheet substructures. The secondary structure of cytochrome c is not disrupted at pressures up to 1470 MPa, and partial transformation of the α-helix of insulin to random coil starts at 960 MPa. Hydrogen-deuterium exchange of protons on the amide groups in the protein interior is increased by external pressure and is associated with the pressure-induced protein conformational changes. A number of studies on the effects of pressure on protein denaturation have been carried out using various high-pressure detection methods: ultraviolet absorbance spectroscopy (Brandts et al., 1970; Hawley, 1971), visible absorbance spectroscopy (Zipp & Kauzmann, 1973), fluorescence intensity spectroscopy (Li et al., 1976), polarization fluorescence spectroscopy (Chryssomallis et al., 1981), and enzyme activity assays (Taniguchi & Suzuki, 1983; Makimoto et al., 1989). These techniques have the great advantage of being applicable to pressure-induced reversible denaturation of proteins to identify the thermodynamic parameters, especially the volume change and compressibility of a protein in solution, because the experiments can be run under dilute conditions at a protein concentration of less than 0.05% w/v. Therefore, these data reflect the intramolecular phenomena of reversible pressure changes and provide the volume changes accompanying the denaturation of proteins, which are due to the difference in partial molal (specific) volume between the native and denatured proteins in solution.

Enzymatic hydrolysis and their effects on conformational and functional properties of peanut protein isolate

2011 ◽  
Vol 127 (4) ◽  
pp. 1438-1443 ◽  
Author(s):  
Guanli Zhao ◽  
Yan Liu ◽  
Mouming Zhao ◽  
Jiaoyan Ren ◽  
Bao Yang
Keyword(s):  
Enzymatic Hydrolysis ◽  
Functional Properties ◽  
Protein Isolate ◽  
Peanut Protein ◽  
Peanut Protein Isolate

scholarly journals Effect of Storage Temperatures on the Moisture Migration and Microstructure of Beef

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xia Li ◽  
Hang Wang ◽  
Waris Mehmood ◽  
Shuyi Qian ◽  
Zhen Sun ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Protein Denaturation ◽  
Water Reservoir ◽  
Free Water ◽  
Surface Hydrophobicity ◽  
Random Coil ◽  
Drip Loss ◽  
Ice Crystal ◽  
Moisture Migration ◽  
Significant Difference

The effects of freezing temperature on the microstructure and moisture migration of beef were investigated, aiming to provide the potential theoretical basis for the beef storage. Drip loss, surface hydrophobicity, and secondary structure of myofibrillar proteins, ice crystal, and micro- and ultrastructure of meat were analyzed at 4°C, −1°C, −6°C, −9°C, −12°C, and −18°C, respectively. Results indicated that the drip loss and surface hydrophobicity of samples stored at −12°C were significantly lower than that stored at 4°C and −1°C (p<0.05) and no significant difference with −18°C (p>0.05). Result from Fourier transform infrared spectroscopy suggested that protein denaturation occurred after storage. There was an increase in α-helices and decline in random coil at lower temperature (−12°C and −18°C). It was indicated that the samples stored at −12°C and −18°C could effectively restrain the denaturation of protein and maintain the stability of secondary structure. The analysis of the ice crystal and micro- and ultrastructure of the muscle indicated that the structure of samples stored at −12°C and −18°C had more integrity and was complete than that stored at 4°C and −1°C. The spaces (water “reservoir” and “channel”) where was the origination of drip were small. Furthermore, the results of low-field nuclear magnetic resonance and 1H magnetic relaxation image showed that the freezing at −12°C could inhibit the migration of immobilized water to free water.

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 ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Soybean Protein ◽  
Surface Hydrophobicity ◽  
Protein Isolate ◽  
Ftir Spectra ◽  
Soybean Protein Isolate

Effect of High Pressure Microfluidization on Secondary Structure of Wheat Gluten in Different Solvents

2013 ◽  
Vol 781-784 ◽  
pp. 770-773
Author(s):  
Zhao Xi Fang ◽  
Nai Jun Yan ◽  
Guo Qin Liu
Keyword(s):  
High Pressure ◽  
Secondary Structure ◽  
Acid Treatment ◽  
Wheat Gluten ◽  
Control Sample ◽  
Random Coil ◽  
Comprehensive Treatment ◽  
Gluten Protein ◽  
Α Helix ◽  
Β Sheet

Far-UV circular dichroism (CD) spectroscopy was used to study the conformation of wheat gluten protein treatmented by dynamic high pressure microfluidization (DHPM), acid treatment and its comprehensive treatment in two solvents. The results showed, the secondary structure of control sample are mainly consist of α-helix and random-coil in phosphate-buffered saline (PBS) and phosphate buffered solution with SDS(SDS), the secondary structure of control sample are mainly consist of β-Sheet and random-coil. The CD data also showed that SDS interacts with the gluten protein and modifies the protein conformation, which switched the conformation from α-helix and β-Turn to β-sheet and random-coil. However, the CD analysis also indicated that some of the ordered structures of α-helix, β-Turn and β-sheet were destroyed and converted random-coil coped with acid in two solvents, in other words, the acid treatment can directed change the secondary structure. Furthermore, the effect of comprehensive treatment (DHPM plus acid) is not equal to the simple sum of the individual treatment effect.

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