Conformation stability, in vitro digestibility and allergenicity of tropomyosin from shrimp (Exopalaemon modestus) as affected by high intensity ultrasound.

The effects of high intensity ultrasound (HIU) modification (power: 100-800 W, 15 min) on the conformation stability, in vitro digestibility and allergenicity of tropomyosin (TM) from Exopalaemon modestus were investigated. HIU treatment oxidized the Cys, Met and Lys in TM and degraded TM to generate protein fragments by HIU-induced free radicals. The α-helix content decreased, while β-sheet, β-turn and random coil increased. The immunoblotting and ELISA data suggested HIU treatment reduced the allergenicity and contributed to higher digestibility of TM. TM had resistance to gastric digestion, while intestinal digestion totally hydrolyzed TM, and the sequential HIU-gastric-intestinal digestion most efficiently hydrolyzed TM and reduced the allergenicity of digestion products. Stronger HIU could loosen TM structure, strengthen the gastrointestinal digestibility of TM and reduce the allergenicity of TM and digestion products to low level.