Effect of protein concentration, pH, lactose content and pasteurization on thermal gelation of acid caprine whey protein concentrates

2005 ◽  
Vol 72 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Stéphanie Bordenave-Juchereau ◽  
Bruno Almeida ◽  
Jean-Marie Piot ◽  
Frédéric Sannier
Keyword(s):  
Whey Protein ◽  
Protein Concentration ◽  
Chloride Content ◽  
Raw Milk ◽  
Whey Protein Concentrate ◽  
Pasteurized Milk ◽  
Thermal Gelation ◽  
90 C 30 ◽  
C 30 ◽  
Influence Of Ph

The influence of pH (4·5–6·5), sodium chloride content (125–375 mM), calcium chloride content (10–30 mM), protein concentration (70–90 g/l) and lactose content on the gel hardness of goat whey protein concentrate (GWPC) in relation to the origin of the acid whey (raw or pasteurized milk) was studied using a factorial design. Gels were obtained after heat treatment (90 °C, 30 min). Gel hardness was measured using texture analyser. Only protein concentration and pH were found to have a statistically significant effect on the gel hardness. An increase in the protein concentration resulted in an increase in the gel hardness. GWPC containing 800 g/kg protein formed gels with a hardness maximum at the pHi, whereas GWPC containing 300 g/kg protein did not form true gels. Whey from pasteurized milk formed softer gels than whey from raw milk. A high lactose content (≈360 g/kg) also reduced the gelation performance of GWPC.

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.

scholarly journals Preparation and Characterization of Whey Protein-Based Polymers Produced from Residual Dairy Streams

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 722 ◽  
Author(s):  
Chalermthai ◽  
Chan ◽  
Bastidas-Oyanedel ◽  
Taher ◽  
Olsen ◽  
...  
Keyword(s):  
Whey Protein ◽  
Protein Concentration ◽  
Milk Proteins ◽  
Protein Isolate ◽  
Whey Protein Concentrate ◽  
Polymer Sheets ◽  
Lower Protein ◽  
Poly Ethylene ◽  
The One

The wide use of non-biodegradable, petroleum-based plastics raises important environmental concerns, which urges finding alternatives. In this study, an alternative way to produce polymers from a renewable source—milk proteins—was investigated with the aim of replacing polyethylene. Whey protein can be obtained from whey residual, which is a by-product in the cheese-making process. Two different sources of whey protein were tested: Whey protein isolate (WPI) containing 91% protein concentration and whey protein concentrate (WPC) containing 77% protein concentration. These were methacrylated, followed by free radical polymerization with co-polymer poly(ethylene glycol) methyl ether methacrylate (PEGMA) to obtain polymer sheets. Different protein concentrations in water (11–14 w/v%), at two protein/PEGMA mass-ratios, 20:80 and 30:70, were tested. The polymers made from WPI and WPC at a higher protein/PEGMA ratio of 30:70 had significantly better tensile strength than the one with lower protein content, by about 1–2 MPa (the best 30:70 sample exhibited 3.8 ± 0.2 MPa and the best 20:80 sample exhibited 1.9 ± 0.4 MPa). This indicates that the ratio between the hard (protein) and soft (copolymer PEGMA) domains induce significant changes to the tensile strengths of the polymer sheets. Thermally, the WPI-based polymer samples are stable up to 277.8 ± 6.2 °C and the WPC-based samples are stable up to 273.0 ± 3.4 °C.

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.

scholarly journals Beneficial Effect of Mildly Pasteurized Whey Protein on Intestinal Integrity and Innate Defense in Preterm and Near-Term Piglets

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1125 ◽  
Author(s):  
Marit Navis ◽  
Vanesa Muncan ◽  
Per Torp Sangild ◽  
Line Møller Willumsen ◽  
Pim J. Koelink ◽  
...  
Keyword(s):  
Enteral Nutrition ◽  
Whey Protein ◽  
Whey Protein Concentrate ◽  
Mucosal Barrier ◽  
Intestinal Damage ◽  
Innate Defense ◽  
Near Term ◽  
C 30 ◽  
The Impact ◽  
Gut Maturation

Background. The human digestive tract is structurally mature at birth, yet maturation of gut functions such as digestion and mucosal barrier continues for the next 1–2 years. Human milk and infant milk formulas (IMF) seem to impact maturation of these gut functions differently, which is at least partially related to high temperature processing of IMF causing loss of bioactive proteins and formation of advanced glycation end products (AGEs). Both loss of protein bioactivity and formation of AGEs depend on heating temperature and time. The aim of this study was to investigate the impact of mildly pasteurized whey protein concentrate (MP-WPC) compared to extensively heated WPC (EH-WPC) on gut maturation in a piglet model hypersensitive to enteral nutrition. Methods. WPC was obtained by cold filtration and mildly pasteurized (73 °C, 30 s) or extensively heat treated (73 °C, 30 s + 80 °C, 6 min). Preterm (~90% gestation) and near-term piglets (~96% gestation) received enteral nutrition based on MP-WPC or EH-WPC for five days. Macroscopic and histologic lesions in the gastro-intestinal tract were evaluated and intestinal responses were further assessed by RT-qPCR, immunohistochemistry and enzyme activity analysis. Results. A diet based on MP-WPC limited epithelial intestinal damage and improved colonic integrity compared to EH-WPC. MP-WPC dampened colonic IL1-β, IL-8 and TNF-α expression and lowered T-cell influx in both preterm and near-term piglets. Anti-microbial defense as measured by neutrophil influx in the colon was only observed in near-term piglets, correlated with histological damage and was reduced by MP-WPC. Moreover, MP-WPC stimulated iALP activity in the colonic epithelium and increased differentiation into enteroendocrine cells compared to EH-WPC. Conclusions. Compared to extensively heated WPC, a formula based on mildly pasteurized WPC limits gut inflammation and stimulates gut maturation in preterm and near-term piglets and might therefore also be beneficial for preterm and (near) term infants.

Microbiological Safety of Cheese Made from Heat-Treated Milk, Part III. Technology, Discussion, Recommendations, Bibliography

1990 ◽  
Vol 53 (7) ◽  
pp. 610-623 ◽  
Author(s):  
ERIC A JOHNSON ◽  
JOHN H. NELSON ◽  
MARK JOHNSON
Keyword(s):  
Heat Treatment ◽  
Whey Protein ◽  
Raw Milk ◽  
Toxin Production ◽  
Ph Control ◽  
Heat Treatments ◽  
Low Risk ◽  
Pasteurized Milk ◽  
Psychrotrophic Bacteria ◽  
Heat Treated

Heat treatment or pasteurization does not adversely affect the cheesemaking process or the resulting physical properties of the cheese. Both types of heat-treatments can correct chemical changes that occur in cold stored raw milk. Thermization on the farm may help control psychrotrophic bacteria in cold stored milk. Some denaturation of whey protein does occur during pasteurization. Heat treatments slightly above current minimum pasteurization requirements can cause body/texture and moisture control problems in cheese. Loss of functionality can adversely affect the marketing of whey protein products. Cheeses made from pasteurized milk ripen more slowly and usually do not exhibit the flavor intensity of cheeses made from raw or heat-treated milk. Swiss and hard Italian type cheese, whose traditional flavor results in part from native milk enzymes and microflora, would also be adversely affected if milk pasteurization for cheesemaking were mandatory. The quality of cheese made from pasteurized milk is consistently better than cheese made from raw milk as evidenced by fewer body and flavor defects consequent to the growth of undesirable bacteria. Either pasteurization or heat-treatment enables improved uniform process control and quality during cheesemaking. Pathogens were prioritized as high, medium, or low risk in cheese. Three organisms, Salmonella, Listeria monocytogenes and enteropathogenic Escherichia coli were judged to be high risk threats to the cheese industry. Staphylococcus aureus was listed as low risk because growth and toxin production is readily suppressed by lactic cultures and acidity (pH) control in cheese. Three actions are recommended:Establish a guideline for minimum heat-treatment of milk for cheesemaking: 64.4°C (148°F) for 16 s or equivalent with adequate process control.Evaluate current safety technology and practices used for cheese manufacture. Support research with primary emphasis on the combined effect of heat-treatment and other current cheese technologies.Evaluate technologies not currently utilized in cheese manufacture for safety potential.

scholarly journals Correlations between the physical properties and chemical bonds of extruded corn starch enriched with whey protein concentrate

RSC Advances ◽  
2017 ◽  
Vol 7 (20) ◽  
pp. 11979-11986 ◽  
Author(s):  
Chen Yu ◽  
Junfei Liu ◽  
Xiaozhi Tang ◽  
Xinchun Shen ◽  
Shaowei Liu
Keyword(s):  
Physical Properties ◽  
Statistical Method ◽  
Whey Protein ◽  
Protein Concentration ◽  
Corn Starch ◽  
Extrusion Temperature ◽  
Whey Protein Concentrate ◽  
Protein Concentrate ◽  
Chemical Bonds

The effects of extrusion temperature and whey protein concentration on the physical properties of corn starch were studied. Correlations between the physical properties of the extrudates and internal chemical bonds in proteins were studied using Pearson's statistical method.

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