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Thermal stability of reconstituted milk protein concentrates: Effect of partial calcium depletion during membrane filtration
- Source :
- Food Research International. 102:409-418
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- Milk protein concentrate (MPC) powders are increasingly utilized in manufacturing of protein fortified beverages. Thermal stability of the protein dispersions is of significant importance in such applications. It is known that a decrease in pH can induce partial dissociation of casein micelles and modify the natural equilibrium of calcium and phosphate between the micelles and the serum phase. The presence of soluble casein may improve the rehydration properties of MPC powders, and may impact their thermal stability. The objective of this work was to investigate the effects of partial acidification of milk prior to ultrafiltration on the heat stability of reconstituted MPC dispersions. Milk protein concentrate powders were prepared from skim milk acidified to pH6.0 by addition of glucono-δ-lactone, and then concentrated using ultrafiltration (UF) and diafiltration (DF). The heat stability of the reconstituted MPC dispersions was studied, by determining heat coagulation time, particle size, turbidity, viscosity, soluble and colloidal calcium and phosphate, and non-sedimentable casein both before and after heating at 120°C. Reconstituted MPC powders made with partially acidified skim milk contained lower soluble calcium and phosphate and exhibited very poor thermal stability compared to MPC powders made with skim milk at its natural pH. The thermal stability of the acidified MPC dispersions was not only recovered by restoration of pH and the serum composition through dialysis against skim milk, but it was improved compared to control MPC dispersions. All dialyzed samples had comparable pH, protein content and calcium and phosphate concentration, but the structure of the casein micelles was altered, causing differences in the type of soluble aggregates. It was concluded that the integrity of the casein micelles and the amount of dissociated, non-sedimentable caseins play a major role in determining the thermal stability of the MPC dispersions.
- Subjects :
- Protein Denaturation
Hot Temperature
Time Factors
food.ingredient
Food Handling
Ultrafiltration
chemistry.chemical_element
Calcium
Micelle
Phosphates
chemistry.chemical_compound
0404 agricultural biotechnology
food
immune system diseases
Casein
Skimmed milk
Thermal stability
Colloids
Micelles
Chromatography
Protein Stability
Viscosity
0402 animal and dairy science
food and beverages
Membranes, Artificial
04 agricultural and veterinary sciences
Hydrogen-Ion Concentration
Milk Proteins
Phosphate
040401 food science
040201 dairy & animal science
Diafiltration
Solubility
chemistry
Milk protein concentrate
Electrophoresis, Polyacrylamide Gel
Powders
Food Science
Subjects
Details
- ISSN :
- 09639969
- Volume :
- 102
- Database :
- OpenAIRE
- Journal :
- Food Research International
- Accession number :
- edsair.doi.dedup.....6b2bf924203df5568e63841b1bd1702c