Jharkhand PSC Prelim Exam 18-Dec-2016 Solved Paper

(1) The whiteness is due to the scattering of light by the colloidal particles of the milk emulsion. Both the fat globules and the smaller casein micelles, which are just large enough to deflect light, contribute to the opaque white colour of milk. The casein micelles contain aggregates of protein molecules and are bounded with the help of calcium phosphate.