Casein maps: Effect of ethanol, pH, temperature, and CaCl2 on the particle size of reconstituted casein micelles

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Although conditions favoring casein micelle aggregation are well known, factors promoting the dissociation of the casein micelle are not fully understood. It was our objective to investigate the ethanol-induced dissociation of micellar casein as affected by temperature and a wide range of pH, along with the concentrations of calcium and casein. Two different concentrations of casein micelles were dispersed in imidazole buffer with 0 to 80% ethanol (vol/vol) and 2 and 10. m. M calcium. Apparent micelle size was determined by dynamic light scattering at 5, 30, and 60°C. In the absence of ethanol, casein precipitation occurred at pH 4.6 in imidazole buffer. Ten to forty percent ethanol promoted casein aggregation (> 1,000. nm) and higher temperature (30 and 60°C) enhanced this effect. Higher ethanol concentrations at 50 to 80% induced the dissociation (< 40. nm) of the casein micelle upon acidification (pH < 5) and alkalization (pH > 8) in imidazole buffer. In addition, higher concentrations of casein (0.25. mg/mL) and calcium (20. m. M) caused the formation of larger aggregates (> 1,000. nm) in the presence of ethanol when comparing with the initial lower concentrations of casein (0.1. mg/mL) and calcium (2. m. M). Casein micelle dissociation can be achieved near the isoelectric pH by modifying the solvent composition and temperature.

Original languageEnglish (US)
Pages (from-to)799-805
Number of pages7
JournalJournal of dairy science
Volume96
Issue number2
DOIs
StatePublished - Feb 1 2013

Fingerprint

Micelles
micelles
Caseins
Particle Size
particle size
casein
Ethanol
ethanol
Temperature
temperature
imidazoles
Calcium
calcium
Buffers
buffers
protein aggregates
light scattering

All Science Journal Classification (ASJC) codes

  • Food Science
  • Animal Science and Zoology
  • Genetics

Cite this

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title = "Casein maps: Effect of ethanol, pH, temperature, and CaCl2 on the particle size of reconstituted casein micelles",
abstract = "Although conditions favoring casein micelle aggregation are well known, factors promoting the dissociation of the casein micelle are not fully understood. It was our objective to investigate the ethanol-induced dissociation of micellar casein as affected by temperature and a wide range of pH, along with the concentrations of calcium and casein. Two different concentrations of casein micelles were dispersed in imidazole buffer with 0 to 80{\%} ethanol (vol/vol) and 2 and 10. m. M calcium. Apparent micelle size was determined by dynamic light scattering at 5, 30, and 60°C. In the absence of ethanol, casein precipitation occurred at pH 4.6 in imidazole buffer. Ten to forty percent ethanol promoted casein aggregation (> 1,000. nm) and higher temperature (30 and 60°C) enhanced this effect. Higher ethanol concentrations at 50 to 80{\%} induced the dissociation (< 40. nm) of the casein micelle upon acidification (pH < 5) and alkalization (pH > 8) in imidazole buffer. In addition, higher concentrations of casein (0.25. mg/mL) and calcium (20. m. M) caused the formation of larger aggregates (> 1,000. nm) in the presence of ethanol when comparing with the initial lower concentrations of casein (0.1. mg/mL) and calcium (2. m. M). Casein micelle dissociation can be achieved near the isoelectric pH by modifying the solvent composition and temperature.",
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Casein maps : Effect of ethanol, pH, temperature, and CaCl2 on the particle size of reconstituted casein micelles. / Ye, Ran; Harte, Federico Miguel.

In: Journal of dairy science, Vol. 96, No. 2, 01.02.2013, p. 799-805.

Research output: Contribution to journalArticle

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