A RAPID ATR FTIR QUALITY-CONTROL METHOD FOR THE DETERMINATION OF FAT AND SOLIDS IN SWEETENED CONDENSED MILK/

A rapid method for the analysis of sweetened condensed milk (SCM) for fat and solids was developed based on attenuated total reflectance (AT R) Fourier transform infrared (FTIR) spectroscopy. FTIR spectra were a cquired for pre-analyzed samples homogenized at room temperature and a t 65 degrees C using a polytron to study the effect of sample treatmen ts. Calibration models were developed using partial-least-squares (PLS ) based on 20 calibration standards and validated using 30 additional samples. The accuracy and reproducibility of the analysis was in the o rder of +/-0.09 and +/-0.03 for fat and +/-0.55 and +/-0.30 for solids respectively. As long as the sample preparation protocol is standardi zed and adhered to, the method will produce good results. The ATR/FTIR method offers both ease of sample handling and rapid analysis turnaro und (similar to 5 min per sample), providing a simple and efficient qu ality control method for determining fat and solids in SCM.