Identification of additive components in powdered milk by NIR imaging methods

Area of Science:

• Food Science
• Analytical Chemistry
• Spectroscopy

Background:

• Ensuring the safety and quality of powdered milk is crucial, particularly in industrial settings.
• Detecting excessive or banned additives requires rapid and reliable analytical methods.
• Near-infrared (NIR) microscopy offers a way to spatially analyze chemical components in complex mixtures like powdered milk.

Purpose of the Study:

• To simulate and identify the distribution of inorganic additives and a banned chemical in powdered milk.
• To establish methods for the express assay of components in powdered milk using NIR microscopy.
• To determine the detection limit of melamine in powdered milk.

Main Methods:

• Near-infrared (NIR) microscopy was employed for chemical imaging.
• Relationship imaging mode was used to identify the distribution of zinc sulfate (ZnSO4).
• Principal component analysis (PCA) coupled with correlation coefficient imaging was used for lactose distribution.
• Classical least square (CLS) regression was utilized for melamine quantification.

Main Results:

• The spatial distribution of inorganic additive ZnSO4 was successfully identified.
• Lactose distribution was visualized using PCA and correlation coefficient imaging.
• The banned additive, melamine, was quantified in powdered milk using CLS regression.
• The detection limit for melamine was determined via relationship imaging.

Conclusions:

• NIR microscopy is a viable technique for the express assay of additives in powdered milk.
• The developed methods allow for the spatial identification and quantification of key components.
• This approach supports quality control and safety assurance in powdered milk production.