STRUCTURE AND STABILITY OF BOVINE MILK CASEIN MICELLES
Keywords:
Casein, thermal stability, micellar structure, hydrolysis, proteinsAbstract
Milk proteins are natural vehicles that provide essential micronutrients, amino acids, as well as a component of the immune system, in addition, they have properties of fundamental importance in the characteristics of many dairy products. Caseins are the main proteins in milk, they comprise around 80% of milk proteins and consist of four main proteins: as1-, as2, B- and k-casein, which have high thermal stability, which provides the dairy products treat milk at high temperatures, such as ultra high temperature milk (UAT). However, some factors such as enzymatic hydrolysis of K-casein, Temperature, pH, excess Ca2+ and addition of ethanol affect the stability of this protein, which are largely present in milk in the form of colloidal particles, known as micelles. The internal structure of the casein micelle is predominantly made up of as1-, as2, B-casein and colloidal calcium phosphate nanoparticles, while k-casein is preferentially located on the surface of the micelle, playing an important role in micellar stability. Interest in micellar casein has remained constant over the years, and research on the subject continues to be carried out, hence the importance of understanding the structure and factors that affect micellar stability.
References
Aoki, T., Toyooka, K., & Kako, Y. (1985). Role of phosphate groups in the calcium sensitivity of αs2-casein. Journal of Dairy Science, 68(7), 1624-1629. http://dx.doi.org/10.3168/jds.S0022-0302(85)81005-5 Aoki, T., Umeda, T., & Kako, Y. (1992). The least number of phosphate groups for crosslinking of casein by colloidal calcium phosphate. Journal of Dairy Science, 75(4), 971-975. PMid:1578034. http://dx.doi.org/10.3168/jds.S0022-0302(92)77838-2 Bouchoux, A., Debbou, B., Gesan-Guiziou, G., Famelart, M. H., Doublier, J. L., & Cabane, B. (2009). Rheology and phase behavior of dense casein micelle dispersions. The Journal of Chemical Physics, 131(16), 165106. PMid:19894981. http://dx.doi.org/10.1063/1.3245956 Bouchoux, A., Gésan-Guiziou, G., Perez, J., & Cabane, B. (2010). How to squeeze a sponge: Casein micelles under osmotic stress, a SAXS study. Biophysical Journal, 99(11), 3754-3762. PMid:21112300. http://dx.doi.org/10.1016/j.bpj.2010.10.019 Bouchoux, A., Ventureira, J., Gesan-Guiziou, G., Garnier-Lambrouin, F., Qu, P., Pasquier, C., Pezennec, S., Schweins, R., & Cabane, B. (2015). Structural heterogeneity of milk casein micelles: A SANS contrast variation study. Soft Matter, 11(2), 389-399. PMid:25388767. http://dx.doi.org/10.1039/C4SM01705F Broyard, C., & Gaucheron, F. (2015). Modifications of structures and functions of caseins: A scientific and technological challenge. Dairy Science & Technology, 95(6), 831-862. http://dx.doi.org/10.1007/s13594-015-0220-y Buchheim, W., & Welsch, U. (1973). Evidence for the submicellar composition of casein micelles on the basis of electron microscopical studies. Nederlands Melk-en Zuiveltijdschrift, 27, 163-180. Dalgleish, D. G. (2011). On the structural models of bovine casein micelles: Review and possible improvements. Soft Matter, 7(6), 2265-2272. http://dx.doi.org/10.1039/C0SM00806K Dalgleish, D. G., & Corredig, M. (2012). The structure of the casein micelle of milk and its changes during processing. Annual Review of Food Science and Technology, 3(1), 449-467. PMid:22385169. http://dx.doi.org/10.1146/annurev-food-022811-101214 Dalgleish, D. G., & Parker, T. G. (1980). Binding of calcium ions to bovine αsl-casein and precipitability of the protein-calcium ion complexes. The Journal of Dairy Research, 47(1), 113-122. http://dx.doi.org/10.1017/S002202990002094X Dalgleish, D. G., Horne, D. S., & Law, A. J. R. (1989). Size-related differences in bovine casein micelles. Biochimica et Biophysica Acta (BBA) - General Subjects, 991(3), 383-387. http://dx.doi.org/10.1016/0304-4165(89)90061-5 Dalgleish, D. G., Spagnuolo, P. A., & Goff, H. D. (2004). A possible structure of the casein micelle based on high-resolution field-emission scanning electron microscopy. International Dairy Journal, 14(12), 1025-1031. http://dx.doi.org/10.1016/j.idairyj.2004.04.008 Darling, D. F., & Dickson, J. (1979). The determination of the zeta potential of casein micelles. The Journal of Dairy Research, 46(2), 329-332. http://dx.doi.org/10.1017/S0022029900017258 Day, L., Raynes, J. K., Leis, A., Liu, L. H., & Williams, R. P. W. (2017). Probing the internal and external micelle structures of differently sized casein micelles from individual cows milk by dynamic light and small-angle X-ray scattering. Food Hydrocolloids, 69, 150-163. http://dx.doi.org/10.1016/j.foodhyd.2017.01.007 Donnelly, W. J., McNeill, G. P., Buchheim, W., & McGann, T. C. A. (1984). A comprehensive study of the relationship between size and protein composition in natural bovine casein micelles. Biochimica et Biophysica Acta, 789(2), 136-143. PMid:6477926. http://dx.doi.org/10.1016/0167-4838(84)90197-3 Dumas, B. R., Brignon, G., Grosclaude, F., & Mercier, J. C. (1972). Structure primaire de la caseine beta bovine: Sequence complete. European Journal of Biochemistry, 25(3), 505-514. PMid:4557764. http://dx.doi.org/10.1111/j.1432-1033.1972.tb01722.x Farrell Junior, H. M. (2011). Milk proteins: Casein nomenclature, structure, and association. In J. W. Fuquay (Ed.), Encyclopedia of dairy sciences (2nd ed., pp. 765-771). Oxford: Elsevier. http://dx.doi.org/10.1016/B978-0-12-374407-4.00430-1. Farrell Junior, H. M., Jimenez-Flores, R., Bleck, G. T., Brown, E. M., Butler, J. E., Creamer, L. K., Hicks, C. L., Hollar, C. M., Ng-Kwai-Hang, K. F., & Swaisgood, H. E. (2004). Nomenclature of the proteins of cows’ milk: Sixth revision. Journal of Dairy Science, 87(6), 1641-1674. PMid:15453478. http://dx.doi.org/10.3168/jds.S0022-0302(04)73319-6 Gaucheron, F. (2004). Interactions caséines-cations. In F. Gaucheron (Ed.), Minéraux et produits laitiers (pp. 81-112). Paris: Lavoisier. Gaucheron, F. (2005). The minerals of milk. Reproduction, Nutrition, Development, 45(4), 473-483. PMid:16045895. http://dx.doi.org/10.1051/rnd:2005030 Hill, R. J., & Wake, R. G. (1969). Amphiphile nature of κ-casein as the basis for its micelle stabilizing property. Nature, 221(5181), 635-639. PMid:5818473. http://dx.doi.org/10.1038/221635a0 Hindmarsh, J. P., & Watkinson, P. (2017). Experimental evidence for previously unclassified calcium phosphate structures in the casein micelle. Journal of Dairy Science, 100(9), 6938-6948. PMid:28690066. http://dx.doi.org/10.3168/jds.2017-12623 Holland, J. W., & Boland, M. J. (2014). Pos t-translational modifications of caseins. In M. Boland, H. Singh & A. Thom pson (Eds.), Milk proteins (2nd ed., pp. 141-168). London: Elsevier. Holt, C. (1981). Some principles determining salt composition and partitioning of ions in milk. Journal of Dairy Science, 64(10), 1958-1964. http://dx.doi.org/10.3168/jds.S0022-0302(81)82797-X Holt, C. (1982). Inorganic constituents of milk III. The colloidal calcium phosphate of cow’s milk. The Journal of Dairy Research, 49(1), 29-38. PMid:6804550. http://dx.doi.org/10.1017/S002202990002210X
