Dust mites in your flour?
By Vicky Henniker-Anandraj - Tuesday, Oct 11, 2011
Dust mites are not just limited to mattresses, sofas and rugs, like most things with legs they like to travel. Chances are at some point they have been in your consumables too. Recent studies have shown that dust mites infest around 7% of all wheat flour in Singaporean homes. The tropical climate in Singapore equates for a dust mite love fest on a greater scale to even that of Lionel Richie’s dulcet tones. In other words, Singapore is all in all the perfect breeding ground for the little critters.
The thought of dust mites in the kitchen is a particularly revolting one and this is especially true if you have seen a photo of them. However, this is certainly not a call to throw out all bags of flour that you have, or anything else that you think might have been infected with them. For the majority of us the inclusion and ingestion of dust mites in flour is not a pleasant thought, and that is as nasty as it gets. However for a few with dust mite allergies, approximately 25% of the Singaporean population, this might cause a problem.
Prof. Dr Hugo Van Bever of NUH has recently seen two patients who have suffered from acute urticaria prompted by ingestion of dust mite contaminated flour. For those highly susceptible to HDM’s (house dust mites) this could also trigger severe asthma attacks.
There are number of points that people with HDM allergies need to bear in mind. When cooking with wheat flour, even if the flour is cooked at high temperatures the HDMs can still trigger an allergic reaction. There are a number of signs to look out for if you think your wheat flour is infested with HDM:
– Severe infestations result in a brownish tinge thorough out the flour, called “mite dust”.
– “Mite dust” gives off a minty odor if crushed.
– The flour will become sticky and at this point will acquire a honey-like smell
Interestingly though if you keep an un-infested packet in a tightly sealed container in the fridge the flour should not develop HDM, as they love a high and humid temperature to breed in, complete with a moisture level of +12% – all of which should not be achievable in the fridge! Wheat flour is also more likely to become infested with HDM than any other flour and once the flour is infected with the HDM it quickly leads to an infestation as they breed at a rate of knots. It is important for people with a HDM allergy to look out for signs of an infestation in their flour.
Take note:
– If a packet of flour is open, keep it in the fridge in a sealed container, and always check for signs of HDM before use.
– Rice, potato and other non-wheat flours are less likely to be contaminated with HDM – they just don’t like to breed in those types of flour as much as they do in wheat flour.
– In a recent survey it was found that glutinous rice, tapioca and corn flour samples did not contain any HDM when stored at room temperature for a 6-week period.
– If dealing with a severe HDM allergy it is best to avoid wheat flour.
Vicky Henniker-Anandraj is a mother of two kids with severe food allergies. She writes on all things allergy, family and fun in Singapore. Working with leading chefs to create allergy-aware meals for readers, as well as developing their own home-style recipes, she also hunts down places that are allergy-safe for her kids.