In vitro gastric and intestinal digestions of pulsed light-treated shrimp extracts.

Pulsed ultraviolet light (PUV), a novel technology most commonly used for microbial inactivation, has recently been employed to effectively mitigate food allergens in peanuts, soybean, shrimp, and almond. Putative mechanisms for the efficacy of PUV in reducing allergen reactivity include photothermal, photochemical, and photophysical effects. To date, there are no published data highlighting the effects of in vitro simulated gastric and intestinal digestion on the stability of PUV reduced allergen reactivity of food. In this study, PUV-treated shrimp extracts were subjected to simulated gastric fluid containing pepsin and simulated intestinal fluid containing trypsin and chymotrypsin, and then tested for changes in allergen potency. SDS-PAGE showed no major band deviation between undigested and digested PUV-treated shrimp extracts. IgE binding to tropomyosin remained markedly decreased as seen in Western blot analysis. Total shrimp allergen reactivity remained unchanged following in vitro peptic digestion and was markedly reduced following in vitro intestinal digestion as illustrated in indirect ELISA. The PUV reduced shrimp allergens remained at a low level under the in vitro simulated digestive conditions. The results inferred that PUV could be a potential method to create less allergenic shrimp products that would remain at a low allergen level under human gastric and intestinal digestive conditions.

Pulsed ultraviolet light reduces immunoglobulin E binding to Atlantic white shrimp (Litopenaeus setiferus) extract.

Pulsed ultraviolet light (PUV), a novel food processing and preservation technology, has been shown to reduce allergen levels in peanut and soybean samples. In this study, the efficacy of using PUV to reduce the reactivity of the major shrimp allergen, tropomyosin (36-kDa), and to attenuate immunoglobulin E (IgE) binding to shrimp extract was examined. Atlantic white shrimp (Litopenaeus setiferus) extract was treated with PUV (3 pulses/s, 10 cm from light source) for 4 min. Tropomyosin was compared in the untreated, boiled, PUV-treated and [boiled+PUV]-treated samples, and changes in the tropomyosin levels were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). IgE binding of the treated extract was analyzed via immunoblot and enzyme-linked immunosorbent assay (ELISA) using pooled human plasma containing IgE antibodies against shrimp allergens. Results showed that levels of tropomyosin and IgE binding were reduced following PUV treatment. However, boiling increased IgE binding, while PUV treatment could offset the increased allergen reactivity caused by boiling. In conclusion, PUV treatment reduced the reactivity of the major shrimp allergen, tropomyosin, and decreased the IgE binding capacity of the shrimp extract.