Incidence and risk factors for latent sensitization to chymopapain: predictive skin-prick tests in 700 candidates for chemonucleolysis

Ingredient and labeling issues associated with allergenic foods

Foods contain a wide range of food ingredients that serve numerous technical functions. Per capita consumer exposure to most of these food ingredients is rather low with a few notable exceptions such as sugar and starch. Some food ingredients including edible oils, hydrolyzed proteins, lecithin, starch, lactose, flavors and gelatin may, at least in some products, be derived from sources commonly involved in IgE-mediated food allergies. These ingredients should be avoided by consumers with allergies to the source material if the ingredient contains detectable protein residues. Other food ingredients, including starch, malt, alcohol and vinegar, may be derived in some cases from wheat, rye or barley, the grains that are implicated in the causation of celiac disease. If these ingredients contain gluten residues, then they should be avoided by celiac sufferers. A few food ingredients are capable of eliciting allergic sensitization, although these ingredients would be classified as rarely allergenic. These ingredients include carmine, cochineal extract, annatto, tragacanth gum and papain. Food manufacturers should declare the presence of allergenic food ingredients in the ingredient listings on product labels so that allergic consumers can know to avoid these potentially hazardous products.

Immunochemical detection of egg-white antigens and allergens in meat products

BACKGROUND

The purpose of this study was to detect antigens and allergens in egg-white byproduct ingredients and after their incorporation in processed pork meat pastes. Commercially prepared foods may have potentially allergenic ingredients (egg, milk, soybean, wheat, and peanut) added in processing. Since allergic patients may react to unidentified ingredients, it is important to assess the allergenic potency of these food proteins added during processing. Egg white was chosen as an experimental model, since egg is one of the most prevalent allergens in food hypersensitivity.

METHODS

Experimental pork meat pastes containing egg white underwent pasteurization and sterilization. Ingredients derived from egg-white or paste extracts were isoelectrofocused and then blotted onto cyanogen bromide-activated nitrocellulose membranes. Egg-white antigens were identified in ingredients and in meat products with rabbit anti-egg-white antiserum by isoelectric focusing immunoblotting. Allergens were identified with sera from sensitized patients. A sensitive ELISA test was developed to detect egg-white proteins in raw, pasteurized, and sterilized meat products.

RESULTS

Antigens and allergens in four egg-white byproducts were detected. Egg-white antigens were detectable in all ingredients and meat pastes by ELISA. Allergens were detected in ingredients and in raw and pasteurized products by immunoprint techniques and ELISA.

CONCLUSIONS

Masked egg-white allergens are recognized by human serum IgE after pasteurization. Egg-white antigens are detectable in sterilized meat by ELISA techniques. Ingestion of processed foods could entail a risk of allergic reactions for sensitized consumers.