The Use of near Infrared Spectroscopy for Determination of Adulteration and Contamination in Milk and Milk Powder: Updating Knowledge

Abstract

This review aims to update information on the use of near infrared (NIR) spectroscopy in identifying and quantifying the presence of adulterants and contaminants in milk and milk powder. Milk and milk products are recognised excellent sources of nutrition globally and are of great economic importance. In recent years, there have been a number of documented incidences of both deliberate adulteration and accidental contamination of foodstuffs. There is a clear need to detect these by a fast, accurate and non-destructive methodology. This has stimulated researchers to explore the possibility of applying NIR technology for their detection. NIR spectroscopy is a logical technique for use as it offers a rapid, low-cost and convenient analysis of key constituents. Fast responses are particularly important to industry, where an answer is needed within minutes. Most important, apart from its powerful prediction capability, the non-destructive nature of this technique is very useful for fast analysis in on-line and at-line inspections and authentication of food. NIR has the potential for detecting milk and milk powder adulteration by both economically motivated adulterants such as melamine as well as contaminants that may have been introduced unintentionally such as microorganisms. In comparison with mid-infrared and Raman, NIR spectroscopy allows the detection of contaminants and their quantification faster and with the same, or better, performances. Furthermore, NIR instrumentation is, in general, less sensitive to environmental conditions and is highly flexible. In particular, for the detection of a very low level of contamination, further investigations are warranted to identify the basis of the calibrations and test their performance when put into routine use. Consumers must have confidence in the analyses which ensure safe and genuine dairy products.