Submitted to: Applied Biochemistry and Biotechnology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/17/2012
Publication Date: 3/22/2012
Citation: Yang, W., Shriver, S., Chung, S., Percival, S., Correll, M.J., Rababah, T.M. 2012. In vitro gastric and intestinal digestions of pulsed light-treated shrimp extracts. Applied Biochemistry and Biotechnology. 166(6):1409-1422. Interpretive Summary: Pulsed ultraviolet light (PUV), is a new technology that is commonly used for inactivation of microorganisms in foods; and has recently been shown to be capable of reducing allergens from extracts of peanuts, soybean, shrimp, and almond. Focus of this study was on PUV-treated shrimp extracts which were reported to be less allergenic than the untreated; however, it is still not clear whether these treated extracts would remain less or more allergenic after being digested in the body. A model system simulating digestive enzymes was tested to determine if the allergenic capacity of the PUV-treated shrimp extracts remain the same after treatment with digestive enzymes. The enzymes involved, included pepsin (gastric enzyme), chymotrypsin, and trypsin (intestinal enzymes). After enzyme treatment, the allergenic capacity was tested using sera from shrimp-allergic individuals. Results showed that the allergenic capacity of PUV-treated shrimp extracts remained unchanged after pepsin digestion; however, further reduction in the allergenic capacity was noted when trypsin/ chymotrypsin was applied. It was concluded that PUV-treated shrimp extracts remained less allergenic after digestion with enzymes. This suggests that PUV could be a potential method to create less allergenic shrimp products. Animal studies are still needed to verify the validity of this study.
Technical Abstract: 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 is 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.