ESTRUTURA E ESTABILIDADE DAS MICELAS DE CASEÍNA DO LEITE BOVINO
Palavras-chave:
Caseína, estabilidade térmica, estrutura micelar, hidrólise, proteínasResumo
As proteínas do leite são veículos naturais, que fornece micronutrientes essenciais, aminoácidos, assim como componente do sistema imune, além disso, possui propriedade de fundamental importância nas características de muitos produtos lácteos. As caseínas são as principais proteínas do leite, compreendem cerca de 80% das proteínas do leite e consistem de quatro proteínas principais: as1-, as2, B- e k-caseína, as quais possuem elevada estabilidade térmica, o que proporciona as indústrias de lacticínio realizar o tratamento do leite a temperaturas elevadas, como leite ultra alta temperatura (UAT). No entanto, alguns fatores como a hidrólise enzimática da K-caseína, Temperatura, PH, excesso de Ca2+ e adição de etanol afetam a estabilidade dessa proteína, que estão em grande parte presentes no leite na forma de partículas coloidais, conhecidas como micelas. A estrutura interna da micele de caseína é constituída predominamente por as1-, as2, B-caseína e de nanopartículas de fosfato de cálcio coloidal, enquanto que a k-caseína está localizada preferencialmente na superfície da micela, assumindo importante papel na estabilidade micelar. O interesse na caseína micelar mantém-se constante ao longo dos anos, e pesquisas sobre o assunto constituem a ser realizadas, por isso a relevância de se entender a estrutura e os fatores que afetam a estabilidade micelar.
Referências
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
Downloads
Publicado
Como Citar
Edição
Seção
Licença
![Creative Commons License](http://i.creativecommons.org/l/by/4.0/88x31.png)
Este trabalho está licenciado sob uma licença Creative Commons Attribution 4.0 International License.