I've never been able to grasp what it is that makes so many people say that celiacs must avoid vanilla flavoring. If you are dealing with Vanilla Extract it typically contains water, alcohol, and vanilla. I see no threat there. I guess that the concern some people have is that the alcohol used to extract the vanilla flavor may have been created from a gluten bearing grain. I think that this risk is quite minute. I doubt that this is very often the case. Even if the alcohol is made from a gluten-bearing grain, I expect that the process of creating the alcohol will have left the proteins behind, rendering the alcohol safe regardless of its source. But even if that fails and their is a trace of protein in the alcohol, there is only going to be a trace of the tainted alcohol in the vanilla flavored food item. So now we are dealing with a trace of something in a trace of something. After evaluating this risk I have concluded that it is so remote that I will enjoy vanilla flavored foods indiscriminately and deliberately not worry about it. Not so much with the worrying.
The grain that begins with Q is quinoa. It is absolutely, positively gluten free. Some people with celiac disease report that their stomach complains when they eat quinoa. This means that those people can't tolerate quinoa, it does not mean that quinoa contains gluten. Quinoa does not contain gluten, and that's the truth.
About maltodextrin, eat it and do not worry. Maltodextrin is prepared as a white powder or concentrated solution by partial hydrolysis of corn starch or potato starch with safe and suitable acids and enzymes. (1) Maltodextrin, when listed on food sold in the USA, must be (per FDA regulation) made from corn or potato. This rule does NOT apply to vitamin or mineral supplements and medications. (2) Donald Kasarda Ph.D., a research chemist specializing on grain proteins, of the United States Department of Agriculture, found that all maltodextrins in the USA are made from corn starch, using enzymes that are NOT derived from wheat, rye, barley, or oats. On that basis he believes that celiacs need not be too concerned about maltodextrins, though he cautions that there is no guarantee that a manufacturer won't change their process to use wheat starch or a gluten-based enzyme in the future. (3) - May 1997 Sprue-Nik News
Remember, just because someone that has celiac disease gets a tummy ache, that fact alone does not establish that some ingredient they selec t at random from something they ate recently actually contains gluten. It might, but then again, they might have just had a tummy ache, or they might choose to suspect the wrong ingredient.
Trust science, question widely held assumptions.