Submitted to: Food and Bioprocess Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/4/2011
Publication Date: 1/2/2013
Citation: Li,Y., Yang, W., Chung, S., Chen, H., Teixeira, A.A., Gregory, J.F., Welt, B.A., Shriver, S. 2013. Effect of Pulsed Ultraviolet Light and High Hydrostatic Pressure on the Antigenicity of Almond Protein Extracts. Food and Bioprocess Technology. 6(2):431-440. Interpretive Summary: Pulsed ultraviolet (PUV) light and high hydrostatic pressure (HHP) are non-thermal food processing technologies, and have been successfully used as sterilization tools to kill bacteria in foods and fruits. Recently, PUV and HHP have also been shown to be capable of reducing the allergenic potency of nut extracts. Since almond allergy is common in people, we determined if PUV and HHP would make almond extracts less allergenic in test-tube experiments. Allergens from PUV- and HHP-treated almond extracts were analyzed using techniques of gel electrophoresis, and immunochemical detection with pooled plasma from almond-allergic patients. Results showed that PUV reduced both the levels of almond allergens and allergenic potency of almond extracts; however, HHP had little effect. We concluded that PUV was effective in reducing the allergenic potency of almond extracts, and that HHP had no effect, probably because the conditions were not optimized. If confirmed (on PUV) by clinical studies, the research would potentially lead to the development of less allergenic almond products and beverages.
Technical Abstract: The efficacy of pulsed ultraviolet light (PUV) and high hydrostatic pressure (HHP) on reducing the IgE binding to the almond extracts, was studied using SDS-PAGE, Western Blot, and ELISA probed with human plasma containing IgE antibodies to almond allergens, and a polyclonal antibody against almond major protein (AMP). Crude almond protein extracts were treated with PUV (3 pulses/s, 10 cm from lamp) for 0.5, 1, 2, 3, 4, 6, 7, and 10 min. In comparison, boiling treatments were also carried out. HHP treatments were conducted at 600 MPa for 5, 15, and 30 min at three temperatures of 4, 21, and 70°C. Western blots and indirect ELISA demonstrated a reduction in the levels of allergens, and IgE binding in PUV-treated extracts at 7 min, which was found to be the optimal time for PUV exposure. Boiling was not as effective as PUV in reducing the overall IgE-binding of the almond extracts. Unlike PUV, HHP did not affect the allergen levels and IgE binding under the conditions tested.