A rapid method for estimating total protein in goat milk by amido black 10B dye

The basic mechanism behind the dye binding method is that insoluble precipitate forms rapidly as acid dye is combined with proteins in an acidified buffer solution. Amido Black 10B is disulfonic acid commonly used in milk protein estimation. A standard curve was plotted between total protein percentage (Kjeldahl) and the difference between the optical densities of the blank and the sample and protein content by dye binding method was estimated by the standard curve. The protein percentage determined by the Kjeldahl and dye-binding methods showed significant (P 0.01) correlation coefficient of 0.989. The difference between the two methods of protein estimation was not significant and ranged from – 0.35% to + 0.33% protein, revealing that Amido Black 10B dye method of determining protein in milk is as accurate as the Kjeldahl procedure. So Amido Black 10B dye binding method is reliable and convenient for routine analysis of goat milk protein.