Lactic acid

In a recent blog bemoaning the failure of wine makers to include allergens in the labeling on the bottles, Ruth at  What Allergy? said that she had had a bad reaction (eczema – hard, liquid filled lumps which itched until scratched – on her eye lids, cheeks, forhead and across her back) after drinking a wine which included lactic bacteria as an ingredient. Given that she is highly allergic to all dairy products she assumed that this was the problem.

Well, it sounds as though it should have been – and it might have been – but then again, it might not…. So if you are confused, so are most other people…

Lactic acid bacteria do not, as such, have anything to do with dairy products; they are a bacteria used widely in the food industry to ferment hundreds of foods from yogurt to sauerkraut. The bacteria feed on sugars (they can only grow when some sort of sugars are present) and, as a result of ‘carbohydrate fermentation’, they produce lactic acid. The lactic acid lowers the carbohydrate content, and therefore the pH level, of the food (makes it more acid) to the point where other micro-organisms are unable to grow – thus dramatically increasing the shelf life of the food. This acidity also changes the texture of the food giving it the more intense and sharper flavours of fermented foods. This process is self limiting as the lactic acid bacteria cannot survive once the food becomes too acidic so, at that point, the process stops.

So far so good. The tricky bit, for those with serious sensitivity, is, on what substrate was the bacteria grown? What sugars were they fed on? If it was lactose then will enough lactose still be present in the bacteria to affect someone who is seriously sensitive? Quite possibly, yes. Similarly, if it was grown on a grain-based substrate such corn, will someone who is highly sensitive to corn react? Theoretically, the protein which causes the sensitivity should have been metabolised by the bacteria but, it is becoming clear that those who are seriously sensitive can react to individual molecules in a protein, not just to whole proteins, so someone who is seriously corn sensitive could react to a bacteria cultured on a corn base.

(If you want to know more about the work being done on the allergenicity of molecules, read the brief report of an Allergy Research Foundation meeting on the Foods Matter site.)

So what does a sensitive person do about lactic acid or lactic bacteria when they see it on label? What they should do is to ask on what substrate it was cultured – but you can just imagine what kind of a response you will get at  the Tesco checkout… Even if you ask the manufacturer, it is more than likely that they will not know – although the more allergen aware manufacturers are starting to realise that this kind of information may be important for their hard core customers.

So, as usual if you are super-sensitive, all you can do is to avoid it – just in case. As of now, lactic acid bacteria is usually cultured on a grain base, but this is not always the case and dairy (eg lactose) could have been used. Hopefully, with greater awareness, will come more information so that you can, again, make that much-to-be-wished-for ‘informed choice’.