Measuring the lactose content in milk

¹ Tomas Bata University in Zlin, Faculty of Applied informatics, Department of Electronic and Measurements, 760 05 Zlin, Czech Republic
² Tomas Bata University in Zlin, Faculty of Technology, Department of Food Technology, 760 05 Zlin, Czech Republic

^a Corresponding author: vaskova@fai.utb.cz

Abstract

Raman spectroscopy has become a powerful and popular tool for food systems analyses lately. Based on characteristic vibrations of the studied material, the information on its content and structure can be answered. In the paper, Raman spectroscopy is studied for a purpose of lactose content in milk assessment. Lactose, the milk disaccharide, in a human organism decomposes during digestion by the act of enzyme lactase to more easily digestible monosaccharides – glucose and galactose. The lack of enzyme lactase causes symptoms of lactose intolerance what limits lactose-intolerant individuals in the intake of milk and dairy products. Lactose-free products in the diet can be a solution. Raman spectroscopy offers rapid measurement independent of the number of chemicals and other in the paper listed benefits. Raman spectra of lactose, glucose and galactose exhibit enough differences to distinguish the content of lactose in milk. C-O-H bending mode at 1087 cm^-1 is used for lactose quantification. The method accuracy for measuring content of lactose was tested on dried milk droplets. Evaluation of the spectroscopic data was related to two different substances - phenylalanine contained generally in the milk and crystal violet used as an internal standard.