Digestibility and Immunoreactivity of Shrimp Extracts Using an In Vitro Digestibility Model with Pepsin and Pancreatin.

UNLABELLED: Shellfish allergy affects 2% of the adult population in the United States. Identification of allergenic shrimp proteins is needed for improved management and assessment of shrimp allergy. We determined the temporal pepsin and pancreatin stability of total shrimp proteins using simulated physiological digestive conditions in vitro. Gel electrophoresis was used to determine protein stability, whereas immunoreactivity of protease stable proteins was determined using rabbit antigen-specific antibodies. Potential allergenicity of protease stable proteins was determined utilizing human sera from shrimp allergic patients. Total shrimp myofibrillar proteins were pepsin- and pancreatin-stable for up to 1 h after initiating digestion, whereas only pancreatin-stable total shrimp proteins were Immunoglobulin G (IgG) immunoreactive. However, shrimp proteins of 32 and 25 kDa were pepsin and/or pancreatin stable and Immunoglobulin E (IgE) reactive, denoting the stability and potential allergenicity. These findings suggest that this in vitro digestibility model may be useful for the identification of shrimp allergenic proteins that are more resistant to physiologic digestive conditions and may elicit an immunologic response in vivo.

PRACTICAL APPLICATION: Unlike other food allergies, shellfish allergy is typically life-long and predominantly affects the adult population. A major difficulty in managing shellfish allergy is the lack of reliable diagnostic assays due to limited knowledge of clinically relevant shellfish allergens. Therefore, the identification and characterization of digestive-stable and immunoreactive food proteins is fundamental to the development of new polyclonal antibodies for improved food allergen detection methods within the food industry.