The study, entitled Effects of Boiling in the IgE-Binding properties of Tropomyosin of Shrimp (Litopenaeus vannamei) and published in the Journal of Food Science, found boiling may cut down the levels of allergen tropomyosin (TM). It added that shellfish allergy is the main cause of food allergy in adults in the US – affecting an estimated 1 in 50 of the population.
The paper said shrimp is often consumed after some degree of cooking – boiling being one such method.
“An understanding of the allergenic properties of shrimp as affected by the cooking process is critical especially for shrimp allergic individuals,” said the authors Guang-Ming Lui et al.
Litopenaeus vannamei was selected because it is the most widely cultured shrimp species in the world- with over 900,000 tonnes consumed annually. The aim of the study was to compare the stability of raw and boiled shrimp extracts or TM of Litopenaeus vannamei and asses how cooking could affect its allergenicity. This was gauged by measuring the levels of binding of Immunoglobulin E (IgE).
The extracts were analysed using two techniques; sodium dodecyl-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis. The level of this binding was determined using western blot and competitive inhibition enzyme-linked immunosorbent assay (iELISA).
The scientists found: “Extract from boiled shrimp produce lower IgE binding than extracts from raw shrimps, which suggest that boiling can be used as a tool in attempting to reduce shrimp allergenicty.”
The study also found the thermal stability of TM prified from boiled shrimp was the same as that of TM prified from raw shrimp. IgE binding activity of boiled TM was stronger than that of raw TM - which suggests it could be more effective in diagnosing seafood allergy.
Source: Journal of Food Science
doi: 10.1111/j.1750-3841.2009.01391.x
Effects of Boiling on the IgE-Binding Properties of Tropomyosin of Shrimp (Litopenaeus vannamei )
Authors: Guang-Ming Liu, Hsiaopo Cheng, Jacqueline B. Nesbit, Wen-Jin Su, Min-Jie Cao, And Soheila J.Maleki