Lactose analysis in lactose-free products: why speed, reliability, and process control are critical

The market for lactose-free products is constantly growing, requiring dairy producers to control residual lactose more and more carefully. Ensuring that a product meets the stated threshold is not only a quality requirement, but also an essential element for consumer safety and proper management of the production process.

However, the determination of lactose-free in delactose products presents some critical analytical issues. The concentrations to be measured are very low, the matrices can be complex, and the data must be available in a time frame compatible with the needs of the plant. For this reason, the choice of analytical method directly affects the manufacturer's ability to monitor the delactosation process and take timely action.

Different analytical approaches are used in the control of residual lactose. Traditional UV enzymatic methods generally rely on NADH formation and reading at 340 nm, with procedures that may require clarification, handling of multiple reagents and extended incubation times.

In contrast, HPLC, High Performance Liquid Chromatography, is a reference technique when separation and quantification of individual sugars is required. It is a suitable method for confirmatory analysis, validation and in-depth characterization of the carbohydrate profile. However, the use of HPLC requires dedicated instrumentation, specialized personnel, extended analytical time and higher operating costs.

In this scenario, a rapid enzyme system such as CDR FoodLab® can play a complementary role in daily production control, providing analytical data in a short time and with a simplified procedure.

The CDR FoodLab® system maintains the initial step of lactose hydrolysis, but generates the analytical signal through a glucose-bound chromogenic reaction. The reading takes place in the visible range at 505 nm by the formation of a colored complex.

This setup allows operation in a spectral region more suitable for routine testing of suitably prepared dairy matrices. Compared with UV readings at 340 nm, measurement in the visible may be less critical in the presence of residual turbidity, protein components or matrix characteristics that make photometric readings at such wavelength more complex.

For process control, this is particularly relevant. The goal is not to replace chromatographic techniques in official validation contexts, but to have a tool that is rapid, repeatable, and consistent with the operational thresholds of the lactose-free market.

In lactose-free products, residual lactose monitoring is often concentrated around the threshold of 0.1 g/100 g. The stated detection limit for CDR FoodLab® of 0.01 g/100 g is therefore adequate for routine monitoring of the delactosation process.

This makes it possible to follow the progress of lactose reduction during enzymatic treatment and to identify when the product reaches the desired threshold. In production, the availability of a result in a short time frame can help optimize enzyme use, reduce waiting times, and limit the risk of release or blockage of nonconforming batches.

Another relevant element concerns the operational management of the method. Traditional UV enzymatic methods can require more elaborate preparations, clarifications, separate reagents and analytical times in excess of 60 minutes.

CDR FoodLab®, on the other hand, is designed to simplify laboratory and plant workflow. For milk, simple dilution is provided, while for solid matrices such as cheese or butter, rapid extraction in water followed by filtration can be used. Reagents are pre-infused and ready to use, with specific components added during the procedure.

This standardization reduces manual variables and makes the method more easily integrated into routine controls.

The reliability of the method is supported by experimental evaluations conducted on lactose-free matrices and commercial samples. Data on correlation with HPLC, repeatability, and applicability of the system under near-routine operating conditions are reported in the full technical paper. Specifically, correlation values with HPLC of R² = 0.9882 in the ACTALIA study and R² = 0.9903 in the verification on commercial samples conducted in an external laboratory are given.

These results support the use of CDR FoodLab® as a rapid analytical tool for process control, capable of providing data consistent with the operational needs of lactose-free production.

The control of residual lactose in delactose products requires analytical methods that are reliable, rapid and compatible with the production flow. HPLC maintains a central role in confirmation and validation analyses, while rapid enzymatic systems allow bringing the analytical data directly into daily process control.

In this context, CDR FoodLab® represents a suitable solution for the routine monitoring of delactosation, thanks to the simplicity of the procedure, the rapidity of the result, and the consistency of analytical performance in the application range of lactose-free products.