Take food allergies seriously; read the labels very carefully

Q: We think my son is allergic to wheat. The doctor has scheduled some testing but didn't say anything about changing his diet. In the meantime we're trying to keep foods with wheat in them away from him. So now I'm reading food labels very carefully. I'm surprised at how many things either say they have wheat or were "processed in a plant with wheat." Is it really that serious that they have to tell us where the food was made?

A: For people with severe allergies, yes, it is that serious. While a peanut allergy is usually the most serious, many more people, especially children, are diagnosed with true allergies to wheat, soy and other proteins. With an allergy, the body reacts to a food protein as though it were an enemy bacteria or virus and tries to destroy it. That attempt to "destroy" causes the hives, diarrhea, congestion or other symptoms we feel.

When a wheat-free food is made in a place where there is wheat, it's too easy for the food to pick up enough wheat protein, from particles in the air or on equipment, to cause a reaction in a sensitive person. One study found that more than half of the foods they tested had an allergen (protein that causes an allergic reaction) just from being made in a plant with the allergen, not because it was in the recipe.

There are many foods produced in completely wheat-free plants. If your child is diagnosed, you will do well to check out the Food Allergy and Anaphylaxis Network at www.foodallergy.org for lots of good suggestions and sources of safe foods.

Q: I just bought several packets of mix for making and canning salsa. We tried one and liked the flavor, just eating it fresh, so decided to get more. But now that I read the directions, it says to can it for 40 minutes in boiling water. By then it's not chunky anymore, it's all gone to mush. I have other canning directions for salsa that only call for 15 or 20 minutes of canning. Can I use the mix for the flavor but only boil it in the jars for 20 minutes?

A: No. You risk some serious food poisoning if you try to change it that way. How long jars of food — anything from peaches to pickles to pie filling — have to be processed to be safe depends on a lot of things. To be safe, the food in the jars has to be hot enough long enough in the very center of the jar to kill any bacteria that might be there.

With salsa, those factors would include how much acidic foods (tomatoes and vinegar) compared to low-acid food (peppers, onions, etc.) are in the mixture. That's usually the biggest factor.

Some bacteria tolerate more acid than others. Acid also affects how fast heat kills them. Another thing that affects the processing time is how thick or runny the mixture is.

Thin, runny foods such as plain tomato juice will get hot in the center of the jar a lot faster than thicker mixtures such as salsa. And at least some of the prepackaged mixes include starch as a thickener. With that you don't have to cook the vegetables as long to get them thick, so they might have more flavor. But you have to process them longer to keep them safe. If the package says the salsa needs 40 minutes of processing, that's the only safe thing you can do. Otherwise you'll need to keep the jars in the refrigerator, without bothering with the processing, until you use them.