Immunochemical analysis of various foods and food ingredients for detectable gluten content: Implications for wheat-allergic and celiac sprue patients

Abstract

Abstract Rationale To reduce the risk for wheat-allergic and celiac patients while allowing them the maximum number of food products in their diet, determining the presence of wheat gluten in non-wheat-containing, “wheat-free”, “gluten-free” foods/ingredients is necessary. Methods A commercially-available wheat gluten immunoassay kit (lower detection limit is 10 ppm gluten) was used to test a variety of foods. Food samples tested included various non-wheat foods at high risk for cross-contamination with wheat, foods labeled “wheat-free” or “gluten-free”, and foods or ingredients commonly avoided by celiac and wheat-allergic patients that originate from wheat or related cereals, but which have questionable gluten content. At least two different lot numbers of each product were tested. Results Most products with questionable wheat content registered below 10 ppm gluten. Food products labeled as wheat or gluten “free” showed levels ranging from 10 ppm to 277 ppm. Malt syrup and extracts registered between 1800 ppm to 2000 ppm gluten. Wheat starches had gluten content ranging from 10 ppm to >5000 ppm. Conclusions Based on the results of this study, distilled products can likely be ingested by celiac patients without problem. Gums are expected to be safe as well. Wheat starches contain varying levels of gluten. It is not recommended that celiac patients consume wheat starches. Malt syrup and extracts had appreciable amounts of gluten and should not be considered safe for celiac patients. Caution must be taken when choosing and consuming food products labeled “wheat-free” or “gluten-free”, as some can contain appreciable amounts of gluten