scholarly journals Fabrication of a Novel Protein Sponge with Dual-Scale Porosity and Mixed Wettability Using a Clean and Versatile Microwave-Based Process

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2298
Author(s):  
Judith Wemmer ◽  
Loredana Malafronte ◽  
Socrates Foschini ◽  
Aline Schneider ◽  
Christian M. Schlepütz ◽  
...  
Keyword(s):  
Protein Denaturation ◽  
Whey Proteins ◽  
Water Evaporation ◽  
Capillary Suction ◽  
Volumetric Heating ◽  
Denatured Protein ◽  
Early Protein ◽  
The Matrix ◽  
Mixed Wettability ◽  
Dual Scale

An open-porous protein sponge with mixed wettability is presented made entirely from whey proteins and with promising applications in biomedicine, pharmaceutical, and food industry. The fabrication relies on an additive-free, clean and scalable process consisting of foaming followed by controlled microwave-convection drying. Volumetric heating throughout the matrix induced by microwaves causes fast expansion and elongation of the foam bubbles, retards crust formation and promotes early protein denaturation. These effects counteract collapse and shrinkage typically encountered in convection drying of foams. The interplay of high protein content, tailored gas incorporation and controlled drying result in a dried structure with dual-scale porosity composed of open macroscopic elongated foam bubbles and microscopic pores in the surrounding solid lamellae induced by water evaporation. Due to the insolubility and mixed wettability of the denatured protein network, polar and non-polar liquids are rapidly absorbed into the interconnected capillary system of the sponge without disintegrating. While non-watery liquids penetrate the pores by capillary suction, water diffuses also into the stiff protein matrix, inducing swelling and softening. Consequently, the water-filled soft sponge can be emptied by compression and re-absorbs any wetting liquid into the free capillary space.

scholarly journals Arc erosion behavior of TiB2/Cu composites with single-scale and dual-scale TiB2 particles

2019 ◽  
Vol 8 (1) ◽  
pp. 619-627 ◽  
Author(s):  
Shaolin Li ◽  
Xiuhua Guo ◽  
Shengli Zhang ◽  
Jiang Feng ◽  
Kexing Song ◽  
...  
Keyword(s):  
Erosion Resistance ◽  
Copper Matrix ◽  
Mechanical And Thermal Properties ◽  
Structure Defects ◽  
Arc Erosion ◽  
Single Scale ◽  
The Matrix ◽  
Tib2 Particles ◽  
Thermal Stability Of ◽  
Dual Scale

AbstractArc erosion behaviors of TiB2/Cu composites with single-scale and dual-scale TiB2 particles fabricated by powder metallurgy were studied. It was revealed that the dual-scale TiB2/Cu composites had fewer structure defects compared with the single-scale TiB2/Cu composites, and TiB2 particles with different size were uniformly distributed in the copper matrix. When the ratio of 2 μm over 50 μm TiB2 particles is 1:2, the density of TiB2/Cu composite is 98.5% and shows best mechanical and thermal properties. The arc duration and energy of TiB2/Cu composites increase with the increase of electric current in contact material testing. Compared with the single-scale TiB2/Cu composites, the arc erosion of dual-scale TiB2/Cu composite with 2 μm+50 μm (1:2) TiB2 was slighter. The anode bulge area and cathode erosion pit of dual-scale TiB2/Cu composite was smaller. The dual-scale TiB2 particles optimize the microstructure and thermal stability of the composite, which is conducive to alleviating arc erosion. The synergistic effect of different sized TiB2 particles in the matrix improved the arc erosion resistance of TiB2/Cu composite during arcing.

In Vitro Attenuation of Thermal-Induced Protein Denaturation by Aerial Parts of Artemisia scoparia

2014 ◽  
Vol 20 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Murad Ali Khan ◽  
Haroon Khan ◽  
Shafiq Ahmad Tariq ◽  
Samreen Pervez
Keyword(s):  
Crude Extract ◽  
Protein Denaturation ◽  
Total Flavonoid ◽  
Significant Activity ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Aqueous Fraction ◽  
Denatured Protein ◽  
Aerial Parts ◽  
Artemisia Scoparia

The goal of this study was to explore the aerial parts of Artemisia scoparia (crude extract, total flavonoid contents, and aqueous fraction) for protein denaturation potential. The crude extract provoked marked attenuation of thermal-induced denatured protein in a concentration-dependent manner with maximum inhibition of 54.05 μg/mL at 500 μg/mL and IC50 of 449.66 μg/mL. When total flavonoid contents were studied, it illustrated most dominant activity concentration dependently with maximum amelioration of 62.16 μg/mL at 500 μg/mL and IC50 of 378.35 μg/mL. The aqueous fraction also exhibited significant activity with maximum of 56.75% inhibition at 500 μg/mL and IC50 of 445.10 μg/mL. It can be concluded on the basis of the results that the crude extract, flavonoid contents, and aqueous fraction of the plant possessed significant inhibition on thermal-induced denatured protein.

Gelation of casein-whey mixtures: effects of heating whey proteins alone or in the presence of casein micelles

2001 ◽  
Vol 68 (3) ◽  
pp. 471-481 ◽  
Author(s):  
CATHERINE SCHORSCH ◽  
DEBORAH K. WILKINS ◽  
MALCOLM G. JONES ◽  
IAN T. NORTON
Keyword(s):  
Heat Treatment ◽  
Whey Protein ◽  
Protein Denaturation ◽  
Whey Proteins ◽  
Treatment Sequence ◽  
Gel Properties ◽  
Casein Micelles ◽  
Gelation Kinetics ◽  
Milk Gelation

The aim of the present work was to investigate the role of whey protein denaturation on the acid induced gelation of casein. This was studied by determining the effect of whey protein denaturation both in the presence and absence of casein micelles. The study showed that milk gelation kinetics and gel properties are greatly influenced by the heat treatment sequence. When the whey proteins are denatured separately and subsequently added to casein micelles, acid-induced gelation occurs more rapidly and leads to gels with a more particulated microstructure than gels made from co-heated systems. The gels resulting from heat-treatment of a mixture of pre-denatured whey protein with casein micelles are heterogeneous in nature due to particulates formed from casein micelles which are complexed with denatured whey proteins and also from separate whey protein aggregates. Whey proteins thus offer an opportunity not only to control casein gelation but also to control the level of syneresis, which can occur.

scholarly journals The Use of Milk Protein in the Production of Jelly Products

2019 ◽  
Vol 48 (3) ◽  
pp. 58-64 ◽  
Author(s):  
Эмилия Крылова ◽  
Emilia Krylova ◽  
Татьяна Савенкова ◽  
Tatyana Savenkova ◽  
Оксана Руденко ◽  
...  
Keyword(s):  
Protein Content ◽  
Food Systems ◽  
Milk Protein ◽  
Protein Denaturation ◽  
New Technology ◽  
Rapid Development ◽  
Whey Proteins ◽  
Gelling Agent ◽  
Biological Value ◽  
Protein Concentrates

According to the most progressive views on nutrition, the composition of food products should involve certain vital nutrients, hence the rapid development of functional, or fortified foods. An analysis of the diet of the Russian population showed a 33% lack of native proteins. Proteins serve as regulators of the genetic function of nucleic acids, participate as enzymes in all stages of the biosynthesis of polypeptides, store and transport oxygen, and perform an immunological function. The research objective was to develop a technology for producing jelly marmalade of high biological value by using milk protein. The studies were performed at the All-Russian Research Institute of the confectionery industry (a branch of V. M. Gorbatov Federal Research Center for Food Systems). The authors employed standard methods, e.g. physico-chemical, rheological, and organoleptic. The research featured jelly marmalade because it has a low nutritional value and a large amount of carbohydrates (70%). To fortify the product, the researchers used concentrated milk and whey proteins with a 80% protein content and a high biological value index (53%–170%). Gelatin served as the gelling agent. Its protein content was 87.2%. The experiment made it possible to establish the optimal ratio of sugar and molasses, the amount of gelling agent (8%), the amount of milk and whey protein concentrates (5%), and the influence of proteins on the viscosity of the jelly mass and its formation. The authors developed a method that makes it possible to introduce protein concentrates into the process of jelly boiling while preventing protein denaturation. The new technology produces jelly marmalade with milk protein content 11.2 g per 100 g, which means that the energy value of the product is 14.2%. According to regulatory documentation, such a product is deemed as a “source of protein”.

Whey protein denaturation in heated milk and cheese whey

1979 ◽  
Vol 46 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Robyn M. Hillier ◽  
Richard L. J. Lyster
Keyword(s):  
Cheese Whey ◽  
Protein Denaturation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Whey Proteins ◽  
Skim Milk ◽  
Heat Stability ◽  
Second Order ◽  
First Order ◽  
Heated Milk ◽  
Native Whey

SUMMARYQuantitative polyacrylamide gel electrophoresis has been used to measure residual native whey proteins remaining after heat treatment of skim-milk and cheese whey in a kinetic study. The denaturation of α-lactalbumin (α-la) appeared to be first order, but was probably a second-order reaction displaying pseudo first-order kinetics. The denaturation of both β-lactoglobulin A and B (β-lgA and β-lgB) followed second-order kinetics while that of serum albumin was more complex, and could equally well be described as first or second order. Equations are given relating logk1(in s-1) to temperature for α-la denaturation in skim-milk between 70 and 95 °C and between 100 and 150 °C. Similarly, equations relating logk2(in lg-1s-1) to temperature are given for ²-lgA in skim-milk between 100 and 150 °C, and for ²-lgB between 95 and 150 °C. The relative heat stability of ²-lgA and ²-lgB was found to vary.Below 95 °C ²-lgA appeared slightly more thermostable than ²-lgB in skim-milk, and the same was observed in cheese whey below 100 °C. Above these temperatures ²-lgB appeared more stable than ²-lgA.Denaturation of ²-lgB was only slightly more rapid in skim-milk than in whey at temperatures below 95 °C, but was significantly slower at higher temperatures.

Enzyme-induced gelation of whey proteins: Effect of protein denaturation

1997 ◽  
Vol 7 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Z.Y. Ju ◽  
J. Otte ◽  
M. Zakora ◽  
K.B. Qvist
Keyword(s):  
Protein Denaturation ◽  
Whey Proteins

scholarly journals ANTIGENIC PROPERTIES OF NATIVE AND REGENERATED HORSE SERUM ALBUMIN

1943 ◽  
Vol 78 (1) ◽  
pp. 1-8 ◽  
Author(s):  
John O. Erickson ◽  
Hans Neurath
Keyword(s):  
Serum Albumin ◽  
Protein Denaturation ◽  
Horse Serum ◽  
Native State ◽  
Immunological Activity ◽  
Denatured Protein ◽  
Antigenic Activity ◽  
Antigenic Properties ◽  
The Mean ◽  
Physical And Chemical

Comparative immunological measurements have been carried out on crystalline horse serum albumin in the native state and after regeneration from 8 M urea solutions. The mean antigenic activity of the regenerated protein has been found to be less than 10 per cent of that of the native, whereas both antigens proved to be immunologically equivalent. The problem of the relation between protein denaturation and immunological activity has been considered and discussed on the basis of known physical and chemical differences between native and denatured protein.

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.

scholarly journals Boron Diffusion in Steel 20

2020 ◽  
pp. 58-62
Author(s):  
E.P. Shevchuk ◽  
V.A. Plotnikov ◽  
G.S. Bektasova
Keyword(s):  
Liquid Glass ◽  
High Hardness ◽  
Ammonium Hydroxide ◽  
Boride Layer ◽  
Boron Diffusion ◽  
Volumetric Heating ◽  
High Refractoriness ◽  
The Matrix ◽  
Steel 20 ◽  
Diffusion Mass

As is known, boriding is carried out to increase the wear resistance and corrosion resistance of iron-carbon alloys. Along with high hardness, borides, unfortunately, have very high fragility and high refractoriness. An effective way to counter the fragility of boride layers is to form a composite structure consisting of inclusions of solid borides in a more plastic matrix. Such coatings can be obtained by volumetric heating in a muffle furnace using a boron paste that besides a mixture of iron and boron powders contained ammonium hydroxide and activated carbon with or without liquid glass. Boriding of a surface is carried out at high temperatures =1000 °С for 5 minutes. It is experimentally found that the microhardness of the surface layer increased by about 30% compared with the microhardness of the substrate, and that the thickness of the boride layer depends on the presence of liquid glass in the coating. It has been established that specially calculated proportions of ammonia, liquid glass, and charcoal contribute to the formation of an extensive diffusion zone of iron borides, the formation of which is due to the anomalously high diffusion mass transfer of boron into the matrix.

scholarly journals The influence of high temperatures on milk proteins

2002 ◽  
Vol 56 (3) ◽  
pp. 123-132 ◽  
Author(s):  
Ognjen Macej ◽  
Snezana Jovanovic ◽  
Jelena Djurdjevic-Denin
Keyword(s):  
High Temperatures ◽  
Milk Fat ◽  
Protein Denaturation ◽  
Whey Proteins ◽  
Milk Proteins ◽  
Casein Micelle ◽  
Casein Micelles ◽  
Rennet Coagulation ◽  
Milk Fat Globule ◽  
Rennet Casein

High temperatures Induce certain changes in milk constituents, but the degree of these changes depends on both the temperature and time of heat treatment. The most pronounced changes take place in milk proteins. The forewarming of milk causes an increase in acidity, the precipitation of soluble Ca-phosphate, whey protein denaturation and coagulation, as well as the interaction with casein micelles, the Maillard browning reaction, the dephosphorylation of casein, the hydrolysis of casein micelles, changes in whey proteins, an extension of the rennet coagulation time and an exchange of the rheological properties of the acid and rennet casein gels, changes in the zeta-potential and casein micelle hydration, the interaction between the milk proteins and proteins of milk fat globule membrane.

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