Testing solutions for the lactose intolerant

An estimated 68% of consumers worldwide have a low ability to digest lactose. Lactose intolerance is an uncomfortable dietary restriction that affects the ability to digest lactose, a sugar found in milk and dairy products.

The intolerance occurs when the intestine does not produce enough of the lactase enzyme, which breaks down lactose so the body can absorb it. After it is diagnosed, there is no cure, only management of the symptoms. According to medical research, the most effective treatment for lactose intolerance is to regulate the diet in accordance with a healthcare provider to reduce or eliminate lactose consumption.¹

Demand for lactose-free dairy is expanding and food testing laboratories need to be able to test dairy samples efficiently. Both the equipment and the consumables used in the process are critical to obtaining accurate results.

Jeff Rohrer, the Director of Applications Development at Thermo Fisher Scientific in Sunnyvale, California, notes that the traditional methods of testing milk for lactose are not as accurate or quick as using new technologies such as ion chromatography (IC) and high-performance liquid chromatography (HPLC).

“The traditional techniques were enzyme- and colormetric-based and very labour-intensive,” said Rohrer. “In these methods, we treat with enzymes in a way that converts the lactose to a coloured compound that we then measure.”

However, this process is often not sensitive enough to detect trace lactose and there can be interferences that cause ‘false positives’, explained Rohrer.

“With new technology, modern methods are more sensitive, automated and directed toward detecting exactly that compound,” asserted Rohrer.

Additionally, the standard for a lactose-free classification “varies country to country”, he explained.

“In France, to define something as lactose-free it has to be 0.01% lactose or less,” he highlighted. “While in Germany, it’s 0.1%, which is 10 times higher.”

Since low levels of lactose are difficult to determine through traditional methods, countries like France and Germany are looking at more advanced methods like IC or HPLC.

IC or HPLC? The point of difference

Not every lab requires a complex testing set-up. According to Rohrer, the correct methods when utilising new technology and automation processes for detecting lactose will depend on the application.

“The IC method is best for people who really need a sensitive analysis. We have something called ‘eluent generation’ that makes the eluents (mobile phases) we need to perform the test automatically. You don’t have to mix your own solutions,” he said.

Elaborating, Rohrer explained the IC lactose testing process in detail.

“We take a milk sample and we add acetic acid to it. Then we precipitate proteins out and then filter that solution through syringe filters that will take out all the particulates. Then we are left with a clear solution that we inject into our system. The system separates lactose from other sugars and detects using electrochemistry. With this detection, we oxidise the lactose which gives us an electronic signal, which we measure.”

Once a sample is prepared, the IC method can be a completely automated process.

“I can do a simple sample preparation, set up my programs and then come back the next morning and have the answer for all my samples,” said Rohrer.

Alternatively, Rohrer breaks down the HPLC method, which is for customers with a more substantial budget.

“This method requires the use of a mass spectrometer, which is placed next to the liquid chromatography,” he said. “It is not for routine samples. HPLC requires a lot more hands-on work.”

It is important to note that the quality of the consumables in a laboratory is critical to the success of either the IC or HPLC method.

“For example, we use the same syringes you would use to administer a vaccine and we move the liquid through a filter,” explained Rohrer. “The quality of that filter affects your samples a lot. Using low-quality filters can result in extra compounds presenting in an analysis.

“Our objective is to ensure that nothing takes away analyte (ie, lactose) from our samples or adds extra compounds,” concluded Rohrer.

Thermo Fisher Scientific understands the criticality of using the right type of consumables for these testing techniques. Its instrument and consumable product range offers applications and methods that should obtain accurate and efficient results in lactose analysis.

If you require help with any of your analyses, get in touch with one of Thermo Fisher Scientific’s specialists.

References

1. John Hopkins Medicine, “Lactose Intolerance” https://www.hopkinsmedicine.org/health/conditions-and-diseases/lactose-intolerance

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