Assessment of gliadin in supposedly gluten-free foods prepared and purchased by celiac patients.
BACKGROUND
The present study was designed to evaluate the presence of gliadin in homemade foods prepared by patients with celiac disease and/or their relatives, as well as in processed products consumed by such patients in São Paulo, Brazil, by enzyme immunoassay (EIA) and Western blot (WB) analysis.


METHODS
One hundred ninety samples were analyzed: 108 homemade foods prepared in homes of patients with celiac disease, 81 processed products, and 1 positive control of homemade food. All samples were analyzed by EIA based on monoclonal antibodies to heat stable omega-gliadins and related prolamins from wheat, rye, and barley. Samples were also analyzed using the WB technique.


RESULTS
Only one (0.9%) of 108 homemade foods contained detectable amounts of gliadin, as determined by EIA. Twelve of 81 processed products contained gliadin by EIA, as follows: 5 of 61 without gluten listed in the ingredients, 2 of 11 malt extracts, 1 of 2 wheat starches, 1 of 2 types of beer, and all 3 positive control products. Gliadin content of these products was between 4 and 10 mg of gliadin/100 g of product, except for the wheat starch sample (28 mg of gliadin/100 g) and all 3 samples with gluten (>4000 mg of gliadin/100 g). The positive control of homemade food contained 152 mg of gliadin/100 g. One hundred three of 190 samples were analyzed by WB, and 21 of these were gliadin positive. A comparison of results obtained by EIA and WB showed no statistical differences between the methods.


CONCLUSIONS
The greater part of the foods prepared in homes of patients with celiac disease and most processed products supposed to be gluten-free did not contain gliadin. Therefore, celiac patients adequately prepare gluten-free homemade food and have the expertise to purchase processed gluten-free food in São Paulo, Brazil.
Sdepanian
V L
VL
Pediatric Gastroenterology Division, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil. sdepanian@nw.com.br
Scaletsky
I C
IC
Fagundes-Neto
U
U
Batista de Morais
M
M
D000911:Antibodies, Monoclonal; D015153:Blotting, Western / Q000379:methods; D002446:Celiac Disease / Q000178:diet therapy*; D005504:Food Analysis; D005903:Gliadin / Q000302:isolation & purification*; D005983:Glutens / Q000737:chemistry; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods
D000911:Antibodies, Monoclonal; D005983:Glutens; D005903:Gliadin