Huppertz Thom, Vaia Betsy, Smiddy Mary A
Department of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
J Dairy Res. 2008 Feb;75(1):44-7. doi: 10.1017/S0022029907002956. Epub 2008 Jan 29.
In this study, the properties of casein particles reformed from alkaline disrupted casein micelles were studied. For this purpose, micelles were disrupted completely by increasing milk pH to 10.0, and subsequently reformed by decreasing milk pH to 6.6. Reformed casein particles were smaller than native micelles and had a slightly lower zeta-potential. Levels of ionic and serum calcium, as well as rennet coagulation time did not differ between milk containing native micelles or reformed casein particles. Ethanol stability and heat stability, >pH 7.0, were lower for reformed casein particles than native micelles. Differences in heat stability, ethanol stability and zeta-potential can be explained in terms of the influence of increased concentrations of sodium and chloride ions in milk containing reformed casein particles. Hence, these results indicate that, if performed in a controlled manner, casein particles with properties closely similar to those of native micelles can be reformed from alkaline disrupted casein micelles.
在本研究中，对由碱性破坏的酪蛋白胶粒重新形成的酪蛋白颗粒的性质进行了研究。为此，通过将牛奶pH值提高到10.0使胶粒完全破坏，随后通过将牛奶pH值降低到6.6使其重新形成。重新形成的酪蛋白颗粒比天然胶粒小，且ζ-电位略低。含有天然胶粒或重新形成的酪蛋白颗粒的牛奶之间，离子钙和血清钙水平以及凝乳酶凝固时间没有差异。重新形成的酪蛋白颗粒在乙醇稳定性和高于pH 7.0的热稳定性方面低于天然胶粒。热稳定性、乙醇稳定性和ζ-电位的差异可以用含有重新形成的酪蛋白颗粒的牛奶中钠离子和氯离子浓度增加的影响来解释。因此，这些结果表明，如果以可控方式进行，可从碱性破坏的酪蛋白胶粒重新形成性质与天然胶粒非常相似的酪蛋白颗粒。
