Near-infrared probe as a quality control tool for milk powder blending processes

This study aims to evaluate the suitability and reliability of Process Analytical Tools (PAT) in monitoring milk powder blending processes. The uniformity end point was predicted using a Near-Infrared (NIR) probe, and subsequently validated using offline Fourier Transform Infrared Spectroscopy (FTIR). A standard milk formulation (SMF) made up of 50% lactose, 40% skim milk powder, and 10% whey protein concentrate was used. Additionally, the detection limit of the NIR probe was investigated using vitamin C powder. The average predicted uniformity end point using the inline NIR fixed reference (63.89 ± 2.06 min), and dynamic reference conformity test (63.00 ± 5.25 min) were comparable with the offline FTIR measurement (56.6 ± 0.71 min). A three-component Partial Least Square Regression (PLSR) model was constructed and validated for vitamin C. The detection limit is 0.11%, which is higher than the vitamin C level commonly found in most infant milk formula (0.035%).