Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk Serum
Micellar casein and casein monomers in milk serum are in a dynamic equilibrium. At temperature below 15–20 °C a considerable amount of casein monomers, β-casein in particular, is released from the casein micelle into the aqueous serum phase. This study investigates the effects of added calcium and r...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-04-01
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| Series: | Foods |
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| Online Access: | https://www.mdpi.com/2304-8158/10/4/822 |
| _version_ | 1797538137685098496 |
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| author | Simon Schiffer Eva Scheidler Tim Kiefer Ulrich Kulozik |
| author_facet | Simon Schiffer Eva Scheidler Tim Kiefer Ulrich Kulozik |
| author_sort | Simon Schiffer |
| collection | DOAJ |
| description | Micellar casein and casein monomers in milk serum are in a dynamic equilibrium. At temperature below 15–20 °C a considerable amount of casein monomers, β-casein in particular, is released from the casein micelle into the aqueous serum phase. This study investigates the effects of added calcium and related variations of pH on this peculiar equilibrium in order to minimize the amount of caseins in the serum and to better understand the casein permeation during microfiltration. The pH was varied in the range of 6.3 to 7.3 and the content of calcium was increased up to 7.5 mM by adding CaCl<sub>2</sub>. Upon equilibration, the milk was separated by ultracentrifugation and the amounts of protein in the supernatant were analyzed. It was shown that the addition of low amounts of calcium shifts the equilibrium towards the micellar casein phase and can, thus, lower the serum casein content induced at low temperatures. Relative to that, the adjustment of pH separately from the CaCl<sub>2</sub> addition had a minor effect on casein concentration and composition in the serum. |
| first_indexed | 2024-03-10T12:27:11Z |
| format | Article |
| id | doaj.art-9610888c148247c4baee7fdc724679dc |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-03-10T12:27:11Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Foods |
| spelling | doaj.art-9610888c148247c4baee7fdc724679dc2023-11-21T14:58:41ZengMDPI AGFoods2304-81582021-04-0110482210.3390/foods10040822Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk SerumSimon Schiffer0Eva Scheidler1Tim Kiefer2Ulrich Kulozik3Chair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, GermanyChair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, GermanyChair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, GermanyChair of Food and Bioprocess Engineering, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, GermanyMicellar casein and casein monomers in milk serum are in a dynamic equilibrium. At temperature below 15–20 °C a considerable amount of casein monomers, β-casein in particular, is released from the casein micelle into the aqueous serum phase. This study investigates the effects of added calcium and related variations of pH on this peculiar equilibrium in order to minimize the amount of caseins in the serum and to better understand the casein permeation during microfiltration. The pH was varied in the range of 6.3 to 7.3 and the content of calcium was increased up to 7.5 mM by adding CaCl<sub>2</sub>. Upon equilibration, the milk was separated by ultracentrifugation and the amounts of protein in the supernatant were analyzed. It was shown that the addition of low amounts of calcium shifts the equilibrium towards the micellar casein phase and can, thus, lower the serum casein content induced at low temperatures. Relative to that, the adjustment of pH separately from the CaCl<sub>2</sub> addition had a minor effect on casein concentration and composition in the serum.https://www.mdpi.com/2304-8158/10/4/822casein micelleserum caseincolloidal interactions |
| spellingShingle | Simon Schiffer Eva Scheidler Tim Kiefer Ulrich Kulozik Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk Serum Foods casein micelle serum casein colloidal interactions |
| title | Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk Serum |
| title_full | Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk Serum |
| title_fullStr | Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk Serum |
| title_full_unstemmed | Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk Serum |
| title_short | Effect of Temperature, Added Calcium and pH on the Equilibrium of Caseins between Micellar State and Milk Serum |
| title_sort | effect of temperature added calcium and ph on the equilibrium of caseins between micellar state and milk serum |
| topic | casein micelle serum casein colloidal interactions |
| url | https://www.mdpi.com/2304-8158/10/4/822 |
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