Q. I'm on a gluten-free diet. Does maltodextrin contain gluten?

A. Yes. It may contain small fragments of protein particles related to gluten. Maltodextrin is a starch which is used as a thickener or texture modifying agent in foods such as pasta sauces, soups, instant gravy, stocks, flavoured milk drinks, instant pudding desserts and cake mixes.

It looks like a white flour and is produced by the partial hydrolysis (break down) of the starch into shorter molecules based on glucose.

What is maltodextrin and where does it come from?

Maltodextrin can be derived from either wheat or maize (corn) or tapioca and the distinction is important. Maize maltodextrin or tapioca maltodextrin is gluten-free, but wheat is not.

The label should tell you which one is present by listing "From maize" or "From wheat" on the list of ingredients. Most do!

Until a few years ago, wheat starch and maltodextrin were permitted on gluten-free diets for coeliacs. However some coeliacs noticed that they developed symptoms of diarrhoea or bloating every time they ate it.

It seems that even such tiny amounts (less than 0.02 per cent) are enough to cause problems for some super-sensitive people. Others report no effect but they too should be wary of consuming any from packet foods.