Researchers based at Hokkaido University and the Watanabe-Kazuhiko Pediatric Clinic in Japan and Pukyong National University in Korea, investigated the impact of the Maillard reaction on the allergenicity of scallop tropomyosin, a major shellfish allergen.
Seafood and fish allergies are believed to touch more than 6.5 million Americans. A recent study found that one in 50 people had an allergy to shrimps, crabs, lobster, squid, scallop, clams, mussels.
The Maillard reaction, called after the chemist Louis-Camille Maillard, is a chemical reaction between an amino acid and a reducing sugar, usually requiring the addition of heat. Like caramelisation, it is a form of non-enzymatic browning.
Each type of food has a very distinctive set of flavour compounds that are formed during the Maillard reaction.
But for this recent study, scientists looked at the effect the Maillard reaction might have on the allergenicity of tropomyosin.
The allergenicity was enhanced at the early stage of the Maillard reaction, but the impact 'trend' depended on the type of reducing sugar used. 2,4,6-Trinitrobenzenesulfonic acid treatment of the lysine residues in tropomyosin showed that the protein surface charge resulting from the Maillard reaction had no effect on the enhancement of the allergenicity.
"The allergenicity was enhanced at the early stage of the Maillard reaction, and the trend of the effect depended on the type of reducing sugar used," they report in the 19 August edition of the Journal of Agricultural and Food Chemistry.
The change in the allergenicity would be closely related to the structural change caused by the Maillard reaction, they conclude.
Tropomyosin is a also a major allergen in several common marine invertebrates - such as shrimp, crab, squid and octopus. The researchers said they would like to examine other seafoods and the structural changes that might occur.