Oscillatory rheological study of the effects of pH and salts on gel development in heated whey protein concentrate solutions

1995 ◽  
Vol 62 (3) ◽  
pp. 469-477 ◽  
Author(s):  
Qingnong Tang ◽  
Owen J. McCarthy ◽  
Peter A. Munro
Keyword(s):  
Ionic Strength ◽  
Whey Protein ◽  
Protein Interactions ◽  
Salt Concentration ◽  
Food System ◽  
Whey Proteins ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Ph Values ◽  
Effects Of Ph

SummaryThe effects of pH and added NaCl or CaCl2 on gel development in heated whey protein concentrate (WPC) solutions were studied by oscillatory rheometry using a Bohlin rheometer, and by qualitative visual and tactile observations. The storage modulus (G′) exhibited maxima at pH values of about 4 and 7, while the phase angle (δ) exhibited minima at the same pH values. At pH 5·5, which lies within the range of the isoelectric points of the whey proteins, G′ was a minimum while δ was a maximum. At pH 7 and 8 G′ increased to a maximum and then decreased as added ionic strength was increased. At pH 4 G′ decreased steadily but slowly with increasing added ionic strength. The effects of CaCl2 were essentially the same as those of NaCl, but occurred at much lower added ionic strength. All the results are discussed in physicochemical terms. The main conclusions were, firstly, that changes in pH and salt concentration both affected gel development by altering the balance between attractive and repulsive protein-protein interactions, and secondly, that the effects of pH, salt concentration and salt type were interactive. Interaction both partly explains the wide variation in gel character and rheological properties among commercial WPC and potentially provides means of tailoring the gelling behaviour of a WPC so that it functions in a desired way in a given food system.

Rheology of whey protein concentrate solutions as a function of concentration, temperature, pH and salt concentration

1993 ◽  
Vol 60 (3) ◽  
pp. 349-361 ◽  
Author(s):  
Qingnong Tang ◽  
Peter A. Munro ◽  
Owen J. McCarthy
Keyword(s):  
Shear Rate ◽  
Whey Protein ◽  
Salt Concentration ◽  
Apparent Viscosity ◽  
Age Effect ◽  
Time Dependent ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Ph Values ◽  
Ph Range

SummaryRheological properties of whey protein concentrate (WPG) solutions were studied in steady shear, using a Bohlin VOR Rheometer, as a function of concentration, temperature, shear rate, shearing time, pH, salt type, salt concentration and solution age. At 22 °C and pH 7, the WPC solutions exhibited Newtonian behaviour up to a concentration of 10% total solids, pseudoplastic behaviour between 10 and 30% and time-dependent shear thinning at 35% and above. The apparent viscosity of solutions at 22 °C and pH 7 was linearly related to concentration up to 8%. The effect of temperature on apparent viscosity in the range 5–60 °C was closely described by the Arrhenius equation. The viscosities of WPC solutions were independent of solution age in the pH range 4–8 at all concentrations up to and including 20%, the precise pH range narrowing as concentration increased. At pH values above or below this range apparent viscosity became dependent on both pH and solution age, the age effect becoming more marked at higher WPC concentrations. Apparent viscosity at pH 7 increased markedly with both CaCl2 concentration and solution age at concentrations above 0·6 M-CaCl2, the age effect in this case increasing with CaCl2 concentration. In contrast, NaCl concentrations of up to 0·8 M-NaCl had little effect on apparent viscosity. The rheological behaviour of WPC solutions changed from time-independent to time-dependent shear thinning at high concentration, at extreme pH values, at high CaCl2 concentration (after ageing) and on heating to above ∼ 60 °C. This change is considered to be caused by the formation of structure in solutions; a 40% solution (at 22 °C and pH 6·75) exhibited classic thixotropic behaviour in a step–shear rate experiment.

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.

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.

scholarly journals WHEY PROTEIN ADDITION TO FACILITATE ACCELERATION OF YOGHURT FERMENTATION

2019 ◽  
Vol 57 (3B) ◽  
pp. 69
Author(s):  
Nguyen Chính Nghia ◽  
Vu Thu Trang ◽  
Do Van Duong
Keyword(s):  
Whey Protein ◽  
Protein Interactions ◽  
Water Retention ◽  
Whey Proteins ◽  
Whey Protein Concentrate ◽  
Water Retention Capacity ◽  
Protein Protein Interactions ◽  
Retention Capacity ◽  
Fermentation Time ◽  
Fresh Milk

Whey proteins were present in appropriate proportion in milk, during heat-treatment at pasteurization temperatures; whey proteins and casein have the ability to form firm gel of uniform porosity through heat-induced protein-protein interactions. In this study, the addition of whey proteins in fresh milk were carry out to investigate whether whey protein would accelerate yoghurt fermentation time and facilitate the yoghurt structure. The results indicated that the addition of whey concentrate 80 increased the water retention capacity of the final product. Whey protein concentrate 80 supplement at the content of 0.8% shortened fermentation time for the product 12.5%. The addition of whey protein also improved the properties of water retention until 26%, viscosity and structure of yoghurt products.

Sign in / Sign up

Export Citation Format

Share Document