Detection of dry milk in pasteurized milk and yoghurt

Two methods were developed to detect dried milk in fresh milk and yoghurt. The first method was based on the reaction with thiobarbeturic acid (TBA) while the second was based on measuring the milk reducing substances (MRS) with ferricyanide. The simple correlation coefficients (r) between per-centage dried milk and TBA (r=O.9861), and MRS (r=O.9994) values were highly significant (P";;O.OI). Therefore, either TBA or MRS methods could be used to detect dried milk in fresh pasteurized milk and yoghurt. However, MRS method could better detect low levels of added NFDM to fresh pasteurized milk and yoghurt