Allergenicity Evaluation Of Shrimp Three Products Of High Pressure In Combination With Enzyme Treatment

The object of study was to reduce allergenicity of shrimp,shrimp meat and shrimp protein through high pressure in combination with enzyme treatment.The changes of allergenicity were detected by enzyme-linked immunosorbent assay?ELISA?.According to the results of ELISA,the conditions for preparing lowest allergenicity of three kinds of shrimp products were determined.Then,the systemic allergic reactions in guinea pigs and the isolated ileal smooth muscle contraction reaction was used to evaluated the reduction of allergenicity.Then,determing the changes of cytokines in the serum of sensitized guinea pigs.The reduction effect of allergenicity was evaluated from the body and the molecular level.Using high pressure in combination with trypsin to prepare shrimp,shrimp meat and shrimp protein,the changes of allergenicity of three kinds of shrimp products were detected by enzyme-linked immunosorbent assay?ELISA?,through the results of ELISA to choose the best conditions to prepare lowest allergenicity shrimp and their products.The results showed that shrimp protein was treated with pressure of 200MPa for 40min at 40?and that 2000U trypsin of per shrimp protein,substrate concentration was 3%,were the optimum conditions for reducing the allergy of shrimp protein.Under these conditions,the allergenicity reduction rate of shrimp protein was 97.043%(The OD_492nm value of the antigen and antibody reaction was 0.0233).The optimum conditions for reducing the allergy of shrimp meat were:at 40?,pressure 200MPa for 40min,the quality of trypsin was 3000U/g,and substrate concentration was 150g/100m L.Under these conditions,the allergenicity reduction rate of shrimp meat was 94.035%(OD_492nm value of the antigen and antibody reaction was 0.045).When the condition was under 200MPa pressure for 40min at40?,the amount of trypsin added is 3000U/g,and substrate concentration was150g/100m L,the allergenicity reduction rate of shelled shrimp was 94.493%(OD_492nm92nm value of the antigen and antibody reaction was 0.041).With balanced salt solution?PBS?as the negative control and untreated shrimp protein as the positive control,guinea pigs were taken as the tested animals.The systemic allergic reactions in guinea pigs and the isolated ileal smooth muscle contraction reaction were obsvered to evaluate the anaphylaxis reaction.Results indicated that allergenicity of shrimps and their products treated by high pressure in combination with trypsin were significantly reduced?P<0.05?but not completely reduced.The allergenicity of shrimp protein using the method of high pressure in combination with enzyme was better than that of shrimp and shrimp meat group.Balanced salt solution?PBS?was used as the negative control and untreated shrimp protein was used as the positive control to observe the changes of cytokines,immunoglobulin and HIS in the serum of allergic guinea pigs.The results showed that the content of IL-1,IL-2,IL-3,IL-4,IL-6,TNF-?,IgE and HIS in the serum of allergic guinea pigs increased significantly.What's more,the ratio of IFN-?and IL-4 in the serum of allergic guinea pigs was significantly reduced.The balance of Th cells in allergic guinea pigs was shifting to Th2 cells.The allergenicity of shrimp and their products were effectively reduced by ultra-high pressure combined with enzyme.Therefore,high pressure in combination with enzyme treatment can effectively reduce the allergenicity of shrimp,shrimp meat and shrimp protein.There were significant changes in some cytokines in the serum of allergic guinea pigs,and more inflammatory factors such as histamine were released.The balance of Th cells in allergic guinea pigs was shifting to Th2 cells.