Oscillatory rheological study of the gelation mechanism of whey protein concentrate solutions: effects of physicochemical variables on gel formation

1993 ◽  
Vol 60 (4) ◽  
pp. 543-555 ◽  
Author(s):  
Qingnong Tang ◽  
Owen J. McCarthy ◽  
Peter A. Munro
Keyword(s):  
Whey Protein ◽  
Protein Concentration ◽  
Loss Modulus ◽  
Whey Proteins ◽  
Gelation Time ◽  
Whey Protein Concentrate ◽  
Effect Of Temperature ◽  
Protein Concentrate ◽  
Gelation Mechanism ◽  
Thermal Gelation

SummaryThe thermal gelation of a commercially available whey protein concentrate was studied by oscillatory rheometry using a Bohlin rheometer. Gelation time increased with decreasing protein concentration with a critical protein concentration (at infinite gelation time) of 6·6%. The effect of temperature in the range 65–90 °C on gelation time was described by an Arrhenius equation with an activation energy of 154 kJ/mol. Gelation time was a minimum at pH 4–6, the isoelectric region of the whey proteins. Small additions of NaCl or CaCl2 dramatically decreased gelation time. Higher protein concentrations always produced higher storage modulus (G′) values after any heating time. Loss modulus (G″) v. time curves exhibited maxima at relatively short times for protein concentrations of 30 and 35%. G′ values for 10% protein concentration increased with temperature for heating times up to 59·5 min. G′ values at 59·5 min for 25% protein concentration were higher at 78 °C than at either 85 or 90 °C. The results are discussed in terms of current theories for biopolymer gelation.

Changes in the gelation mechanism of whey protein concentrate with pH and temperature

1994 ◽  
Vol 61 (1) ◽  
pp. 71-81 ◽  
Author(s):  
Stephen M. Taylor ◽  
Lynn F. Gladden ◽  
Peter J. Fryer
Keyword(s):  
Temperature Dependence ◽  
Whey Protein ◽  
Gelation Time ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Gelation Mechanism ◽  
Gelation Process ◽  
Denatured Protein ◽  
Protein Molecules ◽  
Rate Limiting

SummaryThe percolation model of Steventon et al. (1991) successfully detected changes in the mechanism of whey protein concentrate gelation with pH and temperature by comparing simulated with experimental gelation times. The results demonstrated that at 71 °C and pH 5·2 the formation of an aggregate from two denatured protein molecules (initiation) was the rate-determining step in the gelation process, while at pH 7·0 the addition of denatured protein molecules to an aggregate (propagation) was rate-determining. At pH 5·9, the gelation process was also initiation limited, with the rate being slower than for pH 5·2 solutions, probably owing to electrostatic effects. Analysis of the temperature dependence of the gelation time, and percolation analysis both showed that there was a change in the rate-controlling reaction at 73 °C for gelation at pH 5·2 and 7·0. In the case of pH 7·0 gelation, this change in rate-controlling reaction was not due to a change from denaturation- to aggregation-controlled gelation, but was probably due to a change in the relative rates of interactions between protein molecules. Gelation at pH 5·2 was aggregation-controlled at temperatures below 73 °C, and denaturation-controlled at higher temperatures; there appeared to be another change in rate-limiting reaction at 80–85 °C without a change in mechanism (i.e. it remained denaturation-limited). The activation energies of the rate-limiting reactions determined from analysis of the temperature dependence of gelation time and from percolation analysis were in agreement. This is evidence that the changes in the rate-controlling reaction of whey protein concentrate gelation with temperature and pH were real.

scholarly journals Investigation of whey protein concentration by ultrafiltration elements designed for water treatment

2013 ◽  
Vol 67 (5) ◽  
pp. 835-842 ◽  
Author(s):  
Miroslav Kukucka ◽  
Nikoleta Kukucka
Keyword(s):  
Water Treatment ◽  
Whey Protein ◽  
Protein Concentration ◽  
Whey Proteins ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Excess Amount ◽  
Sweet Whey ◽  
One Year ◽  
Lower Molar

Suitability of polysulfone ultrafiltration membranes (UFM) commercial designed for water treatment have been investigated for separation of protein (PR) from sweet whey. Ultrafiltration (UF) of whey originated from dairy has been realized by self-made pilot plant which has been in service about one year. Influence of two whey temperatures (9 oC and 30 oC) on efficiency of protein concentration has been examined. Application of investigated UF elements has given whey protein concentrate (WPC) with 5 to 6 times excess amount of protein content in regard to starting one. In the same time the prevalent content of lactose has been removed to permeate. Better results have been occurred during the cold whey filtration. Besides the fact that molecular weight cut-off (MWCO) of investigated membranes were 50-100 kDa, results showed very successful concentrating of whey proteins of dominantly lower molar weights than 50-100 kDa. Investigated membranes are beneficial for design and construction of UF plants for exploitation in small dairies.

scholarly journals Research of changes in individual physico-chemical parameters of yoghurts using whey protein concentrates

2019 ◽  
Vol 21 (91) ◽  
pp. 162-166
Author(s):  
N. B. Slyvka ◽  
O. Ya. Bilyk ◽  
O. R. Mikhailytska ◽  
Yu. R. Hachak
Keyword(s):  
Whey Protein ◽  
Whey Proteins ◽  
Lactobacillus Delbrueckii ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Chemical Parameters ◽  
Protein Concentrates ◽  
Organoleptic Characteristics ◽  
Physico Chemical ◽  
Rate Of Decline

The purpose of the work was to investigate the effect of whey proteins and dry whey concentrates on the change of titrated and active acidity during digestion. In order to stabilize the consistency in the production of low-fat yogurts, dry whey was selected that met the requirements of State Standard 4552:2006. It is used to improve the taste of finished products, to add flavor, to improve the texture, as well as to improve overall quality. In addition, dry whey protein concentrate WPC 80 Milkiland was used. The addition of whey protein concentrate does not detract from the organoleptic characteristics of a normalized mixture, which allows it to be used in yogurt technology. The addition of whey proteins has a significant effect on the duration of gel formation. Whey protein concentrate and dry whey reduce the duration of latent fermentation and flocculation stages. The data obtained allows us to predict that they accelerate the coagulation process. This effect is enhanced by increasing the dose of protein concentrates. Conducted coagulation of milk with a different dose and observed changes in titrated and active acidity during the fermentation. Yogurt culture YF-L903, which includes Streptococcus salivarius subsp., Thermophilus, Lactobacillus delbrűeckii subsp. Bulgaricus were used for fermentation. The highest growth rate of titrated acidity is recorded for option 1 (0.5% dry sucrose) and controls that for 4 hours. the fermentation reached 80 °T. The highest rate of decline in active acidity is recorded in option 1 (0.5% dry sucrose serum). All samples for 4 hours of fermentation reached 4.65–4.72 units. pH. Thus, the acidity slightly increases with increasing the dose of serum protein concentrate and does not increase with the use of dry whey.

Interfacial and emulsifying properties of whey protein concentrate by ultrafiltration

2020 ◽  
Vol 26 (8) ◽  
pp. 657-665
Author(s):  
Josiane Kilian ◽  
Ilizandra Aparecida Fernandes ◽  
Anne Luize Lupatini Menegotto ◽  
Clarice Steffens ◽  
Cecilia Abirached ◽  
...  
Keyword(s):  
Whey Protein ◽  
Protein Concentration ◽  
Water Layer ◽  
Whey Protein Concentrate ◽  
Elastic Behavior ◽  
Protein Concentrate ◽  
Emulsifying Properties ◽  
Interfacial Film ◽  
Oil Water ◽  
Present Particle

The aim of this study was to concentrate whey protein by ultrafiltration process, evaluating the pressure at 1–3 bar and temperature of 10–20℃. In the conditions that show the more protein concentration were evaluated the interfacial and emulsifying properties at pH 5.7 and 7.0. The whey concentrate at 10℃ and 1.5 bar showed the higher protein value 36% (w/w), with soluble protein of 33.82% (solubility of 93.94%) for pH 5.7 and 34% (solubility of 94.4%) for pH 7.0, respectively. The whey concentrate powder present particle size distribution between 0.4-110 um. The whey at pH 5.7 and 7.0 was not observed significant differences in the resistance parameters of the oil/water layer interface. The interfacial film formed by the proteins presented an essentially elastic behavior in both pH, and in pH 5.7 the emulsion was more stable with lower diameter droplets. The concentrate whey showed techno-functional properties (emulsification and solubility), which allow the use as ingredients in products of industrial interest in food products such as mayonnaise, ice cream, sauces, and others.

Acute Versus Chronic Effects of Whey Proteins on Calcium Absorption in Growing Rats

2005 ◽  
Vol 230 (8) ◽  
pp. 536-542 ◽  
Author(s):  
Yongdong Zhao ◽  
Berdine R. Martin ◽  
Meryl E. Wastney ◽  
Linda Schollum ◽  
Connie M. Weaver
Keyword(s):  
Whey Protein ◽  
Bone Mineral ◽  
Calcium Absorption ◽  
Whey Proteins ◽  
Dietary Calcium ◽  
Male Rats ◽  
Whey Protein Concentrate ◽  
Dietary Calcium Intake ◽  
Protein Concentrate ◽  
Chronic Effects

The acute and chronic effects of whey proteins on calcium metabolism and bone were evaluated. In acute studies, 8-week-old male rats were gavaged with 50 mg whey protein concentrate (WPC) and 25 mg calcium. 45Ca was administered intravenously or orally. Kinetic studies were performed, and femurs were harvested. Four of seven WPCs significantly increased femur uptake of 45Ca compared with controls. One WPC at 50 mg enhanced calcium absorption over a range of calcium Intakes from 35.1 ± 9.4% to 42.4 ± 14.0% (P < 0.01). Three of the most effective WPCs were tested further in a chronic feeding study. One hundred 3-week-old rats were randomly divided into four adequate dietary calcium (ADC; 0.4% Ca) groups (control of 20% casein and three WPC groups with 1% substitution of casein with each of three WPCs) and two low calcium (LC; 0.2% Ca) groups (control of 20% casein and one WPC group with 1% substitution of casein with one WPC). After 8 weeks, there was no effect of WPCs on femur uptake of 45Ca among ADC groups and there was no effect of WPCs on calcium retention, femur breaking force, femur bone mineral density, or total femur calcium at either dietary calcium intake. However, whole body bone mineral content (BMC) was significantly higher (P < 0.05) in the three whey protein concentrate ADC groups compared with the ADC control group. Total BMC at the proximal tibia in whey protein ADC groups was increased, as shown by peripheral quantitative computed tomography. Our results indicate that the acute calcium absorption–enhancing effect of whey proteins did not persist through long-term feeding in rats. However, the initial enhancement of calcium absorption by whey protein was sufficient to Increase BMC.

Influence of whey and purified whey proteins on neutrophil functions in sheep

1997 ◽  
Vol 64 (2) ◽  
pp. 281-288 ◽  
Author(s):  
CHUN W. WONG ◽  
AI H. LIU ◽  
GEOFFREY O. REGESTER ◽  
GEOFFREY L. FRANCIS ◽  
DENNIS L. WATSON
Keyword(s):  
Whey Protein ◽  
Inflammatory Responses ◽  
Whey Proteins ◽  
Milk Proteins ◽  
Superoxide Production ◽  
Whey Protein Concentrate ◽  
Dependent Manner ◽  
Protein Concentrate ◽  
Milk Whey

The effects of ruminant whey and its purified fractions on neutrophil chemotaxis and superoxide production in sheep were studied. Both colostral whey and milk whey were found to inhibit chemotaxis regardless of whether they were autologous or homologous, but the inhibitory effects were abolished by washing neutrophils with culture medium before their use in the chemotaxis assay. Colostral whey and milk whey also inhibited the chemotactic activity of zymosan-activated serum. Whey fractions of various degrees of purity such as lactoferrin, lacto-peroxidase, lactoferrin–lactoperoxidase, α-lactalbumin, bovine serum albumin and whey protein concentrate were then studied. While none of these proteins showed any effects on chemotaxis, lactoferrin–lactoperoxidase and whey protein concentrate were found to have an enhancing effect on superoxide production in a dose-dependent manner. Our results provide information on the modulatory role of ruminant milk proteins in inflammatory responses and warrant future investigation.

scholarly journals Influence of bleaching on flavor of 34% whey protein concentrate and residual benzoic acid concentration in dried whey proteins

2011 ◽  
Vol 94 (9) ◽  
pp. 4347-4359 ◽  
Author(s):  
M.A.D. Listiyani ◽  
R.E. Campbell ◽  
R.E. Miracle ◽  
L.O. Dean ◽  
M.A. Drake
Keyword(s):  
Benzoic Acid ◽  
Whey Protein ◽  
Acid Concentration ◽  
Whey Proteins ◽  
Whey Protein Concentrate ◽  
Protein Concentrate

scholarly journals Research of functional and technological properties of whey protein concentrate in technologies of whipped candy masses

2021 ◽  
Vol 83 (2) ◽  
pp. 169-174
Author(s):  
T. V. Kalinovskaya ◽  
E. Y. Bogodist
Keyword(s):  
Whey Protein ◽  
Foam Stability ◽  
Whey Proteins ◽  
Licorice Root ◽  
Whey Protein Concentrate ◽  
Root Extract ◽  
Protein Concentrate ◽  
Technological Properties ◽  
Foaming Agents ◽  
Organoleptic Characteristics

In the confectionery industry, egg whites are most often used as foaming agents. Other foaming agents, such as soy proteins, blood albumin, sugar beet extract, soap root extract, licorice root, have not found widespread use, since they do not meet the requirements for organoleptic characteristics. Recently, much attention has been paid by manufacturers to the use of milk proteins. The production of dairy products produces significant amounts of whey, which, despite its high nutritional value, is still underutilized in the food industry. The article is devoted to the study of the functional and technological properties of whey proteins, combined mixtures of whey protein concentrate and egg white. Theoretical information on the functional and technological properties of proteins is presented. The technological factors affecting foaming and foam stability are considered. When performing the research, the generally accepted and special research methods were used. The foaming capacity and stability of the protein foam were determined by the Rauch method. Surface tension was measured by the stalagmometric method. Determination of the structure and dispersion of protein foams was carried out using an electron microscope. The functional and technological properties of whey protein concentrate have been investigated. It was found that when whey proteins were used, the whipped masses had stable stability, which was provided by the increased ability of proteins to hydration, surface activity, the type of intermolecular interactions, as well as an increased denaturation temperature and the ability to form gels. Thus, the totality of the studies carried out shows the feasibility of further study and use of whey proteins when creating a new assortment of whipped candy masses.

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