Measurement of ionic calcium, pH, and soluble divalent cations in milk at high temperature

On-Nom, Nattira; Grandison, Alistair S.; Lewis, Michael

doi:10.3168/jds.2009-2634

Cited by 81 publications

(76 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It was also shown that Ca 2+ in permeate decreased as temperature increased. On-Nom et al (2010) found that Ca 2+ increased in both UF permeates and dialysates as temperature increased. It has been proposed that both pH and ionic calcium in milk show considerable temperature dependence.…”

Section: Discussionmentioning

confidence: 96%

“…TDVC concentration was shown as the average of three measurements by the EDTA titration method. The procedure involved titrating 5 mL milk, 1 mL ammonia buffer solution (7 g ammonium chloride and 25 g ammonia solution, specific gravity 0.88, made up to 100 mL with distilled water) and 0.02 mL calmagite indicator against 0.01M EDTA solution until the colour of milk changed from pink to blue (On-Nom et al, 2010).…”

Section: Analytical Proceduresmentioning

confidence: 99%

See 1 more Smart Citation

Partitioning of calcium and magnesium (total divalent cations) during membrane filtration of milk

Lin

Grandison

Lewis

2015

Journal of Food Engineering

Self Cite

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 96%

Section: Analytical Proceduresmentioning

confidence: 99%

Partitioning of calcium and magnesium (total divalent cations) during membrane filtration of milk

Lin

Grandison

Lewis

2015

Journal of Food Engineering

Self Cite

View full text Add to dashboard Cite

“…Ca 2+ in milk sample and dialysates were determined using a Ciba Corning 634 analyzer (On-Nom et al 2010). This instrument was calibrated with five Ca 2+ standard solutions (0.25, 0.5, 1.0, 2.5 and 5.0 mM).…”

Section: Measurement Of Ca 2+mentioning

confidence: 99%

Naturally occurring variations in milk pH and ionic calcium and their effects on some properties and processing characteristics of milk

Nian¹,

Chen²,

Aikman

et al. 2012

Int J of Dairy Tech

View full text Add to dashboard Cite

Considerable variations were found for ionic calcium and pH in milk from individual cows. Milk with lower pH tended to have a higher Ca2+ concentration, although the relationship was weak. Milk samples with a higher Ca2+ concentration and lower pH produced less sediment during in‐container sterilisation, which was contrary to expectations. Rennet coagulation time was lower for milk with a higher Ca2+ concentration, but curd firmness was not related to Ca2+ concentration. There was a poor correlation between the pH reduction caused by acid addition and that resulting from increasing temperature. Sediment formation was related to pH change at high temperature.

show abstract

“…Heat treatment of milk generally produces reversible effects on the salt partition when allowance is made for pH change and sufficient time is allowed for reequilibration (Pouliot et al, 1989a,b;On-Nom et al, 2010). However, mineral-rich deposits build up over time on heated surfaces during milk processing operations such as heat sterilization.…”

Section: Environmental Effects On the Partition Of Milk Saltsmentioning

confidence: 99%

Invited review: Caseins and the casein micelle: Their biological functions, structures, and behavior in foods

Holt

Carver

Ecroyd

et al. 2013

Journal of Dairy Science

393

240

View full text Add to dashboard Cite

A typical casein micelle contains thousands of casein molecules, most of which form thermodynamically stable complexes with nanoclusters of amorphous calcium phosphate. Like many other unfolded proteins, caseins have an actual or potential tendency to assemble into toxic amyloid fibrils, particularly at the high concentrations found in milk. Fibrils do not form in milk because an alternative aggregation pathway is followed that results in formation of the casein micelle. As a result of forming micelles, nutritious milk can be secreted and stored without causing either pathological calcification or amyloidosis of the mother's mammary tissue. The ability to sequester nanoclusters of amorphous calcium phosphate in a stable complex is not unique to caseins. It has been demonstrated using a number of noncasein secreted phosphoproteins and may be of general physiological importance in preventing calcification of other biofluids and soft tissues. Thus, competent noncasein phosphoproteins have similar patterns of phosphorylation and the same type of flexible, unfolded conformation as caseins. The ability to suppress amyloid fibril formation by forming an alternative amorphous aggregate is also not unique to caseins and underlies the action of molecular chaperones such as the small heat-shock proteins. The open structure of the protein matrix of casein micelles is fragile and easily perturbed by changes in its environment. Perturbations can cause the polypeptide chains to segregate into regions of greater and lesser density. As a result, the reliable determination of the native structure of casein micelles continues to be extremely challenging. The biological functions of caseins, such as their chaperone activity, are determined by their composition and flexible conformation and by how the casein polypeptide chains interact with each other. These same properties determine how caseins behave in the manufacture of many dairy products and how they can be used as functional ingredients in other foods. aBStraCtA typical casein micelle contains thousands of casein molecules, most of which form thermodynamically stable complexes with nanoclusters of amorphous calcium phosphate. Like many other unfolded proteins, caseins have an actual or potential tendency to assemble into toxic amyloid fibrils, particularly at the high concentrations found in milk. Fibrils do not form in milk because an alternative aggregation pathway is followed that results in formation of the casein micelle. As a result of forming micelles, nutritious milk can be secreted and stored without causing either pathological calcification or amyloidosis of the mother's mammary tissue. The ability to sequester nanoclusters of amorphous calcium phosphate in a stable complex is not unique to caseins. It has been demonstrated using a number of noncasein secreted phosphoproteins and may be of general physiological importance in preventing calcification of other biofluids and soft tissues. Thus, competent noncasein phosphoproteins have similar patterns of phosp...

show abstract

Measurement of ionic calcium, pH, and soluble divalent cations in milk at high temperature

Cited by 81 publications

References 16 publications

Partitioning of calcium and magnesium (total divalent cations) during membrane filtration of milk

Partitioning of calcium and magnesium (total divalent cations) during membrane filtration of milk

Naturally occurring variations in milk pH and ionic calcium and their effects on some properties and processing characteristics of milk

Invited review: Caseins and the casein micelle: Their biological functions, structures, and behavior in foods

Contact Info

Product

Resources

About