Abstract:
Amorphous lactose, as an important component of freshly produced milk powder, crystallizes to its crystalline form during storage, which damages the fat globules and releases free fat. As a result, the solubility and quality of milk powder are greatly affected. Therefore, quantifying the lactose crystallinity becomes important for storage and production of milk powder. The lactose crystallinity can be determined by different technologies such as vibrational spectroscopy and X-ray diffraction (XRD). However, at present, there is no reliable method of determining the lactose crystallinity in milk powder. In this project, XRD, Raman spectroscopy (Raman) and Fourier-transform infrared spectroscopy (FTIR) are used to quantitatively detect the lactose crystallinity in milk powder. Partial least squares regression (PLS) models are established on the data from above three techniques. In addition, the reliability of the models is validated by thermal-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). After experiment, the results show that the XRD model is suitable for detecting the low lactose crystallinity in milk powder.
