Increasing the Accuracy of the Golding Plastic Bead Test for Determining Solids-not-fat in Normal Milk

Abstract

Substituting the Golding plastic bead density of skimmilk for that of whole milk reduced the error of estimation from regression (SD) for the solids-not-fat in milk. However, the greatest reduction was when per cent protein in skimmilk, beads sinking in skimmilk, and per cent fat in the whole milk were used in the regression equation.Protein in skimmilk in the regression equation did not reduce the standard deviation as much in comparison with per cent protein in whole milk as comparing equations with beads sinking in skimmilk with beads sinking in whole milk. The standard deviation of all equations ranged from 0.096 to 0.139. For speed and accuracy the best method for large numbers of analyses should be based on regression coefficients for per cent fat and protein in whole milk. The choice of the regression equation, among those tested, would depend upon the laboratory and its sophistication.