scholarly journals Changes of secondary structure and surface tension of whey protein isolate dispersions upon pH and temperature

2014 ◽  
Vol 32 (No. 1) ◽  
pp. 82-89 ◽  
Author(s):  
M. Tomczyńska-Mleko ◽  
E. Kamysz ◽  
E. Sikorska ◽  
C. Puchalski ◽  
S. Mleko ◽  
...  
Keyword(s):  
Surface Tension ◽  
Secondary Structure ◽  
Whey Protein ◽  
Protein Concentration ◽  
Whey Proteins ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Protein Solutions ◽  
The Difference ◽  
Secondary Structure Of Proteins

The secondary structure of proteins in unheated and heated whey protein isolate dispersions and the surface tension of the solutions were investigated at different pH. Heating protein solutions at 80°C results in an increase of unordered structure. Nevertheless, the difference between the contents of unordered structure in the unheated and heated samples increases with increasing pH of the solution. At low protein concentrations the surface tension decreased with increasing protein concentration to about 5 mg/ml. For the heated solution, a similar trend was observed in the decrease in the surface tension with increasing concentrations of protein. In both cases, the curves depicting the surface tension as a function of protein concentration could be fitted to the exponential function with a negative exponent, but with the heated solutions lower values of surface tension were observed. Studies on the surface tension of whey protein isolate solutions prove that the unfolding of whey proteins, revealed by changes in the secondary structure, causes a decrease in the surface tension.

scholarly journals Mineral modulation of thermal aggregation and gelation of whey proteins: from ?-lactoglobulin model system to whey protein isolate

2003 ◽  
Vol 83 (5) ◽  
pp. 353-364 ◽  
Author(s):  
Florence Caussin ◽  
Marie-H�l�ne Famelart ◽  
Jean-Louis Maubois ◽  
Sa�d Bouhallab
Keyword(s):  
Whey Protein ◽  
Whey Proteins ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Model System ◽  
Thermal Aggregation

scholarly journals Acute effects of whey protein isolate on blood pressure, vascular function and inflammatory markers in overweight postmenopausal women

2011 ◽  
Vol 105 (10) ◽  
pp. 1512-1519 ◽  
Author(s):  
Sebely Pal ◽  
Vanessa Ellis
Keyword(s):  
Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Postmenopausal Women ◽  
Whey Protein ◽  
Glucose Control ◽  
Vascular Function ◽  
Inflammatory Markers ◽  
Whey Proteins ◽  
Whey Protein Isolate ◽  
Protein Isolate

Previous evidence indicates that chronic consumption of dairy whey proteins has beneficial effects on CVD risk factors. The present study investigated the postprandial effects of whey protein isolate on blood pressure, vascular function and inflammatory markers in overweight and obese postmenopausal women. This was a randomised, three-way cross-over design study where twenty overweight and obese postmenopausal women consumed a breakfast meal in conjunction with one of three supplements: 45 g whey protein isolate, 45 g sodium caseinate or 45 g of a glucose control. Fasting and postprandial blood samples, blood pressure and pulse wave analysis readings were taken for up to 6 h. After consumption of the meal, both systolic and diastolic blood pressure, and augmentation index (AI) decreased initially for all interventions and gradually returned to baseline levels by 6 h. However, there were no significant differences in AI, systolic or diastolic blood pressure within or between the glucose control, casein or whey groups. There were also no significant group effects on plasma inflammatory markers (IL-6, TNF-α and C-reactive protein). The health effects previously seen with chronic whey protein ingestion were not seen in the acute 6 h postprandial period in relation to blood pressure, vascular function or inflammatory markers when compared with casein and a glucose control. This suggests that such effects are better observed from the long-term consumption of whey proteins.

scholarly journals Studies on Available Utilization of Whey Proteins Part III. Effect of Preheating at High Temperature under Vacuum on Heat Aggregation of Whey Protein Isolate.

1995 ◽  
Vol 42 (10) ◽  
pp. 756-761 ◽  
Author(s):  
Hirofumi FUJINO ◽  
Michio MUGURUMA ◽  
Kazuhiko MORI ◽  
Daisuke TSUENO ◽  
Akihiro SASAKI ◽  
...  
Keyword(s):  
High Temperature ◽  
Whey Protein ◽  
Whey Proteins ◽  
Whey Protein Isolate ◽  
Protein Isolate

scholarly journals The Effect of Atmospheric Plasma on the Perception of Taste and Mixability of Powdered Whey Protein Isolate

2018 ◽  
Author(s):  
Heidi Lightfoot
Keyword(s):  
Whey Protein ◽  
Whey Proteins ◽  
Clinical Trial Design ◽  
Whey Protein Isolate ◽  
Food Supplement ◽  
Protein Isolate ◽  
Inorganic Materials ◽  
Atmospheric Plasma ◽  
Functional Characteristics ◽  
The Right

Powdered whey protein is most often used as a food supplement to enhance athletic performance, but it also has a role in health and wellness as well as the pharmaceutical sectors. Given the dynamic array of roles across several industries, understanding the functional characteristics of whey proteins is of great interest. Protein structure can be altered via plasma-surface modification (PSM), a method which is based on plasma as a means to alter a material’s surface structure and as such its functional characteristics. So far PSM has been utilized to alter the surfaces of inorganic materials but there is growing interest in its applications with organic materials such as food proteins. To date, the effect of atmospheric plasma on the perception of mixability and taste of whey protein isolate has not been explored; the purpose of this study is to investigate whether PSM could be effectively utilized to alter the two. Psychometric measures of mixability and taste were gathered during a single-blind, randomized clinical trial design during which subjects ingested 28g of either PSM treated or untreated whey protein isolate powder. A 30.26% increase in perceived mixability and 12.5% in perceived taste were observed upon treatment with PSM, indicating that plasma treatment does not negatively impact the perception of mixability and taste of whey protein isolate and under the right conditions could promote an improvement in these characteristics.

Cold-Set Whey Protein Isolate Gels: The Influence of Aggregates Concentration on Viscoelastic Properties

2011 ◽  
Vol 312-315 ◽  
pp. 1143-1148
Author(s):  
M. Vázquez da Silva ◽  
João M.P.Q. Delgado
Keyword(s):  
Whey Protein ◽  
Protein Concentration ◽  
Room Temperature ◽  
Young Modulus ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Holding Time ◽  
Solution Viscosity ◽  
Experimental Conditions ◽  
Weak Gels

The physical and structural properties of cold-set whey protein isolate gels are largely influenced by the protein concentration and the denaturation conditions, namely temperature and holding time. In this work, we systematically varied the protein concentration, the temperature and holding time of denaturation in order to screen their impact on the resulting heat denatured whey protein isolate (HD-WPI) solution viscosity and gel elasticity. The gelation of the HD-WPI solutions was induced, at room temperature, through the addition of magnesium chloride. Based on the assumption that solution turbidity is associated with light scattered by protein aggregates, an aggregate concentration was computed for the HD-WPI solutions. For all experimental conditions, HD-WPI solution viscosities and gels Young modulus data fall, respectively, on two single curves when plotted against the computed aggregates concentration. Three concentration regimes corresponding to non gelling solutions, weak gels and strong gels could be identified. In this study was verified that cold-set gels produced upon addition of Mg2+ had a large spectrum of elastic properties.

scholarly journals Calcium Chelation by Phosphate Ions and Its Influence on Fouling Mechanisms of Whey Protein Solutions in a Plate Heat Exchanger

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 259
Author(s):  
Luisa A. Scudeller ◽  
Pascal Blanpain-Avet ◽  
Thierry Six ◽  
Séverine Bellayer ◽  
Maude Jimenez ◽  
...  
Keyword(s):  
Whey Protein ◽  
Protein Denaturation ◽  
Whey Proteins ◽  
Pilot Scale ◽  
Protein Isolate ◽  
Protein Solutions ◽  
Plate Heat ◽  
P Concentration ◽  
Denaturation Kinetics ◽  
Calcium Chelation

Fouling of plate heat exchangers (PHEs) is a recurring problem when pasteurizing whey protein solutions. As Ca2+ is involved in denaturation/aggregation mechanisms of whey proteins, the use of calcium chelators seems to be a way to reduce the fouling of PHEs. Unfortunately, in depth studies investigating the changes of the whey protein fouling mechanism in the presence of calcium chelators are scarce. To improve our knowledge, reconstituted whey protein isolate (WPI) solutions were prepared with increasing amounts of phosphate, expressed in phosphorus (P). The fouling experiments were performed on a pilot-scale PHE, while monitoring the evolution of the pressure drop and heat transfer coefficient. The final deposit mass distribution and structure of the fouling layers were investigated, as well as the whey protein denaturation kinetics. Results suggest the existence of two different fouling mechanisms taking place, depending on the added P concentration in WPI solutions. For added P concentrations lower or equal to 20 mg/L, a spongy fouling layer consists of unfolded protein strands bound by available Ca2+. When the added P concentration is higher than 20 mg/L, a heterogeneously distributed fouling layer formed of calcium phosphate clusters covered by proteins in an arborescence structure is observed.

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