Raman Spectroscopy for Quality Control of Canned Milk Powder

Under current geopolitical restrictions, the Russian food industry needs domestic methods and equipment for the rapid quality control of common dairy products, such as canned milk powder. The article describes the Raman spectra analysis applied to pasteurized and skim milk powder at different temperatures (45 ± 5; 70 ± 5; 80 ± 5°C). The thermal regime had a significant effect on the spectral profiles. Higher pasteurization temperatures resulted in a 31.2% intensity reduction in the lactose-associated region (270–280 cm⁻¹), triggered significant protein transformations (890–900 and 1,450–1,460 cm⁻¹), and altered the fatty acid composition (2,910–2,920 and 3,190–3,210 cm⁻¹). Higher temperatures correlated with lower milk protein peaks. The skim milk powder demonstrated a more complex peak profile than the pasteurized milk samples. The peaks at 440−450 cm–1 reflected the lactose changes; the peaks at 1,260−1,270 and 1,660−1,670 cm–1 illustrated the transformation of protein structures during pasteurization. Selective peaks were registered at 1,300−1,310 cm–1 in the sample processed at 45 ± 5°C and at 1,350−1,360 cm–1 in the pasteurized samples. The temperature factor had no direct effect on the carbohydrate and protein composition. However, the decrease in the intensity of the peaks for the protein components may suggest post-pasteurization structural modifications. Further research is required to compare the physicochemical properties of products and their spectral characteristics. The method of Raman spectroscopy showed strong potential for identifying spectral markers of thermal stress in milk during drying and could form a basis of a new protocol for assessing the thermal class of milk powder.