Researchers develop faster gluten detector

The number of people suffering from coeliac disease and gluten sensitivities has been increasing, causing the food industry to develop more food options to suit their needs. But some individuals continue to suffer from symptoms even after consuming foods that claim to be ‘gluten-free’.

Current tests that detect gluten in food are failing to identify all of the substances, meaning products may be wrongfully labelled as gluten-free. Researchers from the University of Minnesota recognised this could be a major health concern and developed an alternative gluten detector that can supposedly measure different sources of gluten quicker than current systems.

Gluten is a collection of proteins commonly found in wheat, barley and oats. The benchmark used to detect the levels of these proteins in foods is the enzyme-linked immunosorbent assay (ELISA), but there are a number of problems associated with this system.

Not only can it be inconsistent and can provide false negatives, but a different ELISA is needed to detect each type of gluten — barley, wheat or oat. This is because some people may be sensitive to proteins from one source but not another. Other tests are also ineffective; DNA-based sensors are not accurate, and mass spectrometry is costly and requires technical expertise.

Published in ACS Sensors, researchers created an immunological assay based on floating gate transistors (FGT).

The American Chemical Society explained: “Their test is in a device that includes tiny microchannels for a sample to move through. If a sample contains gluten, the substance can bind to one of three capture agents, which can be antibodies or a DNA-based aptamer, that specifically latch onto gluten proteins from certain sources. This binding causes a shift in the voltage readout of the transistor and can provide a chemical fingerprint that tells researchers whether the gluten was from barley or wheat, for example.”

With fewer processing steps and automated sampling, this sensor produces results 45 minutes faster than the ELISA. The FGT sensors can still detect less than 20 parts per million (ppm) of gluten. According to the U.S. Food and Drug Administration, this is the most unavoidable gluten that is allowed in food in order for it to be labelled gluten-free.

The Food Standards Code, on the other hand, states that foods that test below 200 ppm are considered low-gluten, and gluten-free is when there is no detectable gluten.

A more effective, faster gluten detector should help address the growing demand for low-gluten and gluten-free food options.

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