Food Allergies - Influence of Biotechnology - Part IV

Assessment

There are a series of steps that are recommended to assess the allergenic potential of food produced through agricultural biotechnology (7, 10). The step-wise progression helps to assure the safety of these novel foods (7, 10, 12, 14).

1.) The source of the introduced gene. This first step addresses whether the gene is from a source with no allergenic history, a less commonly allergenic food (foods not included in the most common allergenic foods list, presented earlier), or from a commonly allergenic food.

2.) Amino acid sequence similarity. The amino acid sequences of genes from the sources should be compared to other amino acid sequences, including known allergens as well as known 'safe' food proteins.

3.) Stability to digestion/processing. Many allergens display stability to digestive enzymes and processing. However, common food proteins with no history of allergenicity degrade when exposed to digestive enzymes and processing conditions. Thus simulated digestive conditions, as well as processing, provides a method to assess the potential for proteins introduced into food plants to be allergenic.

4.) Immunoassay tests. Solid phase immunoassay tests, such as RAST and ELISA, can help to evaluate the potential allergenicity of foods. If these in vitro tests are negative or ambiguous, then it is recommended to proceed to a skin prick test. If the skin prick test does not provide evidence of allergenicity, a challenge test should be performed, under controlled clinical conditions. Ideally 14 individuals’ sera should be used, and if just one person shows a positive result from exposure to the protein, the product should be labeled, detailing the source of the transferred gene.