Application of two dimensional correlation Fourier Transform Infrared spectroscopy (2D-COS-FTIR) to the quantification of carbohydrates in milk powder

Abstract

The importance of milk and its products accelerated their adulteration as well as their characterization in term of techniques used, composition determination and adulteration quantification. Fourier Transform Infrared spectroscopy (FTIR) is one of the most widely used and increasingly developed methods to identify chemical contaminations and determine their concentrations. This study employs FTIR and two dimensional correlation (2D-COS) spectroscopies to detect milk powder adulteration with sucrose, lactose and starch in the concentrations range from 0.0 % to 6.0 % w/w. With the help of synchronous 2D-COS-FTIR spectra, the FTIR regions from 830 to 930 and 930–1200 cm−1 were determined as the qualified regions for the detection and carrying out quantitative analysis of milk adultered carbohydrates. Based on the area beneath the corresponding region or the height of a specific band limits of detection were determined as 0.25, 1.2 and 1.5 % for sucrose, starch and lactose respectively. The method was applied on commercial milk powder samples and one sample was assigned to have been adultered with 4 % sucrose. FTIR spectroscopy combined with 2D-COS offers an advanced tool for rapid screening and quantification of milk adulteration.