PPM Contamination of Gluten in Food

 

With all the talk of gluten contamination I just thought I'd do a few calculations.

I weighed an 8-10 cm. potato and it weighed about 200 grams. So if you take a double adult portion of mashed potatoes then it is probably about 1 kilogram or 1000 grams.

Wheat flour contains between 8 and 14 percent gluten. (I got this from a site called www.cookingforengineers.com which appears very interesting if you want to find out things like this.) I'll use 13 percent as this is average for bread making flour.

So let's contaminate the mashed potato with different levels of gluten using wheat flour.

200 ppm would mean that 1.54 grams of flour had been added.

So how big is that amount of flour?

Now a cubic metre of wheat flour weighs 593 Kilograms or a cubic centimetre would weigh about 0.593 grams. (I got this from www.simetric.co.uk which gives the density of many materials. It actually lists gluten by itself, which is slightly heavier than flour.)

So that means that to get 200 ppm in the kilogram of mashed potato you would have to add about 2.5 cubic centimetres of flour. i.e. that would be 1 cm x 1 cm x 2.5 cm. or about half of a large heaped teaspoon. (A heaped teaspoon is about five cubic centimetres. But that seems a lot to me.) Interestingly, you would probably add less salt than that when you cook the potatoes.

So even a low level of 10 ppm still needs about 0.125 cubic centimetres of flour, which is probably a generous pinch.

I have checked this, but if anybody can find fault please let me know. Years ago I used to do these sort of calculations all the time as an instrument engineer, but I'm rather rusty these days.