The ultrasonic spectroscopy (US) and the traditional methods (TM) used for the measurement of milk physical-chemical characteristics were studied and the correlations between these methodologies and their accuracies were estimated. Milk density, solids-non-fat (SNF), protein and fat contents were determined in 65 raw milk samples by both methods. Means of density determined by US and TM did not differ (P=0.14), although no significant correlation was found (P=0.08) between the methods used for the determination of this characteristic. Means of SNF, protein and fat contents determined by US and TM differed (P=0.04, P<0.0001 and P<0.0001, respectively). Correlations between both methods used for the analysis of these characteristics were positive and significant (r=0.0109, r=0.0007 and r= <0.0001, respectively), and the accuracies of the methods for these analysis were 0.160, 0.062 and 0.145, respectively. The regression equation of US results on TM for fat content showed a coefficient of determination of 0.5936.
milk; physical-chemical analysis; ultrasound; traditional method; correlation
