Keeping ahead in chemical food safety

Member–funded research is providing us with the opportunity to assess the use of next generation analytical techniques to provide more rapid results, greater sensitivity and the ability to detect emerging food safety risks, as the following examples demonstrate. To find out more contact us.

Detecting human saliva on foreign bodies

When someone claims that a foreign body has been found in their mouth whilst eating a product, we are often asked to test whether the foreign body has been in contact with human saliva. We have evaluated a lateral flow immunochromatographic test for human saliva detection (RSID™–Saliva).

We screened a wide range of foodstuffs for false positive cross reactivity or interference in the test, including those known to contain amylase enzymes (sprouting seeds, honey and commercial Bacillus alpha amylase). None of the foodstuffs gave a false positive result. Results with foodstuffs frequently associated with foreign bodies being found in them indicate that the kit has the potential to test for low levels of human saliva on different types of foreign bodies recovered from different food types. Certain foreign bodies, for example glass, may not retain saliva as well as others, so this must be taken into account when interpreting the results.

Detecting inorganic arsenic in rice and seafood

Inorganic arsenic is toxic and dietary exposure has been linked to increased risk of some cancers, as well as skin lesions. However, organically bound arsenic is essentially non–toxic. As organic arsenic can occur in relatively high levels in some foods, it is very important that analysis can distinguish between the two forms, in order to ensure the maintenance of food safety whilst not creating unnecessary concern.

Rice is potentially a source of inorganic arsenic in the diet. We have implemented an improved method for inorganic arsenic analysis in rice and other food products. Species–specific hydride generation following low–temperature sample extraction is used for on–line separation of inorganic and organic arsenic species, with subsequent detection by inductively coupled plasma mass spectrometry. We have also demonstrated the application of the method to seafood, which typically can have relatively high levels of organic arsenic.

Identifying mustard

Mustard is widely used in seasonings, sauces and other preparations and can arise as a ‘masked’ allergen, leading to serious allergic reactions. Analysis by other antibody or DNA methods can be difficult, especially where the sample is cooked. We used mass spectrometry to try to identify suitable marker compounds to routinely screen for the presence of mustard in foods. Allyl isothiocyanate seems to be a potential marker for the presence of black or brown mustard in food preparations. However, it is naturally present in some other foods, such as beans, cabbage, horseradish and cauliflower, which could potentially lead to misleading results in foods also containing these ingredients.