Effects of thermal processing on digestion stability and immunoreactivity of the Litopenaeus vannamei matrix†
Many types of shellfish, including shrimp, are sometimes cooked before ingestion. Hence, it is necessary to investigate how cooking (boiling, pressure treatment or none (raw)) affects the structure, digestibility and immunoreactivity of multi-component shrimp muscle. Protein extraction, simulated gastrointestinal digestion, immunoreactivity, immunoglobulin E (IgE)-mediated human mast cell degranulation, morphology, particle size and UV absorbance scanning were used to investigate changes in the shrimp muscle upon treatment. The extractability of proteins and allergens was highest with 0.5 mol L−1 NaCl. Pressure treatment increased the digestibility and reduced the immunoreactivity of shrimp edible portions. Thermal processing induced the production of regular fiber bundles, blue shifts of absorbance peaks and reduction of particle size in the complex food matrix. These changes in macro- and micro-structure can further affect gastrointestinal digestibility and immunoreactivity due to the interactions between multiple components in the whole food. In conclusion, the digestibility, immunoreactivity and structure were altered by thermal processing of the complex food matrix.