Allergenicity Reduction of Shrimp (<i>Penaeus vannamei</i>) via Fucoidan-Mediated Covalent Modification: Insights from Epitope Modifying Effect

Covalent modification is an effective strategy for reducing allergenicity to individual allergens, but there are few studies on this strategy modifying specific amino acids within epitopes under the influence of food matrix. This study used fucoidan to covalently modify shrimp (<i>Penaeus vannamei</i>) and combined mass spectrometry and bioinformatics techniques to explore epitope modification. The results showed that lower concentrations (<2.50%) of fucoidan facilitated the covalent modification reaction and effectively modified amino acid sites in the loop regions of allergens, including lysine, asparagine, and methionine. In contrast, higher concentrations (>5.00%) of fucoidan hindered the reaction and modified amino acid sites in the helix regions of allergens, including asparagine, lysine, and methionine. The RBL-2H3 cells model confirmed that modification of hemocyanin epitopes was the main reason for reduced allergenicity. Overall, fucoidan-mediated covalent modification can effectively modify various allergenic epitopes in shrimp, which is a potential strategy to reduce shrimp allergenicity.