Protein Ingredients Control in Gluten Free Products Using SDS-PAGE, Developed Competitive Enzyme Immunoassays and Commercial ELISA Kits

Cellerino Karina

doi:10.11648/j.wjfst.20180201.12

Abstract

Some protein ingredients declared in the label of gluten free products are allergenic proteins (milk, soy and egg). The proper identification of these proteins in food products is important for consumers who have food allergies. The aim of this study was to control the presence of protein ingredients declared in the label of gluten free products. Samples were analyzed with sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), using an extractive solution of total proteins (Tris-ClH buffer 0.0625 M with 3% sodium dodecylsulfate and 2% 2-mercaptoethanol; pH: 6.8) and a selective solvent for the extraction of caseins (isopropanol 55° + 2-mercaptoethanol / ISO + ME). Developed Competitive enzyme immunoassays were used for the detection / quantification of milk, soy and egg proteins in products elaborated with rice flour. Specific polyclonal rabbit antiserums against milk, soy and egg proteins were used as primary antibodies in these competitive enzyme immunoassays. Commercial ELISA kits from Neogen, R-Biopharm and Romer were used to verify the results. In some samples undeclared allergens were detected. Correct allergens labeling is very important for the safety of allergic consumers. In conclusion, it is possible to identify all the proteins ingredients in these gluten-free foods studied, using a combination of electrophoretic methods and immunochemical methods.

Highlights

Food allergies are a growing problem in developing countries and in emerging countries like Argentina
The aim of this study was to control the presence of protein ingredients in gluten free products
In most of the samples that were analyze, the protein ingredients of corn, sorghum, rice, egg, ovalbumin, potato, soy and milk were identified with the sodium dodecyl sulfate (SDS)-PAGE methodology, using extractive protein solution

Summary

Introduction

Food allergies are a growing problem in developing countries and in emerging countries like Argentina. The main food groups that generate allergic reactions are the "big eight": milk, eggs, soy, wheat, peanuts, nuts, fish and crustaceans [1]. Undeclared allergens in commercial foods are very dangerous for consumers who have food allergies. The clinical symptoms of an allergenic reaction can range from skin and/or gastrointestinal symptoms to anaphylaxis [2]. Food manufacturers must be very carefully in allergen labeling. There is a need of methodology that enables the detection of allergenic proteins in products. The most common methodology for the analysis of these proteins is ELISA. There are no Latin American companies that produce ELISA kits and in Argentina these kits are very expensive [3]

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Conclusion