Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content
Micellar calcium phosphate (MCP) content of skim milk was modified by pH adjustment followed by dialysis. Turbidity, casein micelle size and partitioning of Ca and caseins between the colloidal and soluble phases of milk were determined. Protein structure was characterised by Fourier transform infra...
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| Formato: | Artigo |
| Idioma: | English |
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MDPI AG
2024-01-01
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| coleção: | Foods |
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| Acesso em linha: | https://www.mdpi.com/2304-8158/13/2/322 |
| _version_ | 1827369621128216576 |
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| author | Elaheh Ahmadi Tatijana Markoska Thom Huppertz Todor Vasiljevic |
| author_facet | Elaheh Ahmadi Tatijana Markoska Thom Huppertz Todor Vasiljevic |
| author_sort | Elaheh Ahmadi |
| collection | DOAJ |
| description | Micellar calcium phosphate (MCP) content of skim milk was modified by pH adjustment followed by dialysis. Turbidity, casein micelle size and partitioning of Ca and caseins between the colloidal and soluble phases of milk were determined. Protein structure was characterised by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (<sup>1</sup>H NMR), whereas organic and inorganic phosphorus were studied by phosphorus-31 nuclear magnetic resonance (<sup>31</sup>P NMR). The sample with the lowest MCP content (MCP7) exhibited the smallest particle size and turbidity, measuring 83 ± 8 nm and 0.08 ± 0.01 cm<sup>−1</sup>, respectively. Concentrations of soluble caseins increased with decreasing MCP levels. At ~60% MCP removal, FTIR analysis indicated a critical stage of structural rearrangement and <sup>31</sup>P NMR analysis showed an increase in signal intensity for Ca-free Ser-P, which further increased as MCP concentration was further reduced. In conclusion, this study highlighted the importance of MCP in maintaining micellar structure and its impact on the integrity of casein micelle. |
| first_indexed | 2024-03-08T09:55:07Z |
| format | Article |
| id | doaj.art-a59c3cf94145480c9e50eafb95b34264 |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-03-08T09:55:07Z |
| publishDate | 2024-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Foods |
| spelling | doaj.art-a59c3cf94145480c9e50eafb95b342642024-01-29T13:52:42ZengMDPI AGFoods2304-81582024-01-0113232210.3390/foods13020322Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate ContentElaheh Ahmadi0Tatijana Markoska1Thom Huppertz2Todor Vasiljevic3Advanced Food Systems Research Unit, Institute for Sustainable Industries and Liveable Cities, College of Sport, Health and Engineering, Victoria University, Melbourne, VIC 3001, AustraliaAdvanced Food Systems Research Unit, Institute for Sustainable Industries and Liveable Cities, College of Sport, Health and Engineering, Victoria University, Melbourne, VIC 3001, AustraliaAdvanced Food Systems Research Unit, Institute for Sustainable Industries and Liveable Cities, College of Sport, Health and Engineering, Victoria University, Melbourne, VIC 3001, AustraliaAdvanced Food Systems Research Unit, Institute for Sustainable Industries and Liveable Cities, College of Sport, Health and Engineering, Victoria University, Melbourne, VIC 3001, AustraliaMicellar calcium phosphate (MCP) content of skim milk was modified by pH adjustment followed by dialysis. Turbidity, casein micelle size and partitioning of Ca and caseins between the colloidal and soluble phases of milk were determined. Protein structure was characterised by Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance (<sup>1</sup>H NMR), whereas organic and inorganic phosphorus were studied by phosphorus-31 nuclear magnetic resonance (<sup>31</sup>P NMR). The sample with the lowest MCP content (MCP7) exhibited the smallest particle size and turbidity, measuring 83 ± 8 nm and 0.08 ± 0.01 cm<sup>−1</sup>, respectively. Concentrations of soluble caseins increased with decreasing MCP levels. At ~60% MCP removal, FTIR analysis indicated a critical stage of structural rearrangement and <sup>31</sup>P NMR analysis showed an increase in signal intensity for Ca-free Ser-P, which further increased as MCP concentration was further reduced. In conclusion, this study highlighted the importance of MCP in maintaining micellar structure and its impact on the integrity of casein micelle.https://www.mdpi.com/2304-8158/13/2/322micellar Ca phosphatecasein micellesecondary structure of proteinsFTIRNMR |
| spellingShingle | Elaheh Ahmadi Tatijana Markoska Thom Huppertz Todor Vasiljevic Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content Foods micellar Ca phosphate casein micelle secondary structure of proteins FTIR NMR |
| title | Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content |
| title_full | Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content |
| title_fullStr | Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content |
| title_full_unstemmed | Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content |
| title_short | Structural Properties of Casein Micelles with Adjusted Micellar Calcium Phosphate Content |
| title_sort | structural properties of casein micelles with adjusted micellar calcium phosphate content |
| topic | micellar Ca phosphate casein micelle secondary structure of proteins FTIR NMR |
| url | https://www.mdpi.com/2304-8158/13/2/322 |
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