People who suffer from lactose intolerance do not have the ability to break down lactose, a naturally occurring sugar present in many food products. The number of lactose free food products has grown considerably over the years, and with it regulations appeared on maximum allowed limits of lactose. In many European countries, the limit of lactose in lactose-free labeled products was decreased from 100 to now 10 mg/100g product.
An application note by Knauer describes a method for analysing lactose levels in lactose free products. The method uses HPAEC with pulsed amperometric detection, using the Antec Electrochemical Detector. The method for detection of Lactose is similar to the other carbohydrate methods in our website. The above chromatogram shows an overlay of a lactose standard and a lactose free food product.
The application note by Ingenieria Analitica shows different conditions. It allows for determination of a couple of other carbohydrates of interest as well. In case of lactose-free milk/diary products the manufacturers enzymatically convert the Lactose into Glucose and Galactose. Furthermore, in pasteurized milk a part of the existing lactose isomerizes into Lactulose, epi-Lactose and 1-Lactulose. In the note from Ingenieria Analitica these carbohydrates of interest are measured as well.
For analysis of low concentrations of lactose we use the ALEXYS Analyzer for Carbohydrates. For best sensitivity we use the DECADE Eilte with Sencell in combination with a new 4-step pulse for detection. This new PAD waveform minimizes the wear of the gold electrode. It increases the flow cell life-time and has less maintenance.