Identification of additive components in powdered milk by NIR imaging methods.

The express assay of excessive additives in powdered milk is of vital necessity, especially during industrial production. Near-infrared microscopy provides chemical information on the spatial distribution and cluster side of components in milk-based products when materials are mixed together. Distributions of two additive components and one banned chemical in powdered milk were simulated in this study. The distribution of inorganic additive ZnSO4 was identified using the relationship imaging mode. The distribution image of lactose was obtained by assigning the wavenumber region and by using principal component analysis coupled with correlation coefficient imaging. In addition, classical least square regression was employed to quantify the banned additive, melamine, in the powdered milk. Lastly, the detection limit of melamine in powdered milk was determined using the relationship imaging mode.