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Browsing by Author "Russo, Guilherme Alexandre Alves"

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  • Effects of high-pressure processing (HPP) on the structure and potential of allergenicity of β-Parvalbumin from the European sea bass (Dicentrarchus Labrax)
    Publication . Russo, Guilherme Alexandre Alves; Power, Deborah; Anjos, Liliana
    Fish allergy is an adverse immune response which affects  3% of the world population and is currently without cure. Parvalbumin (PARV) is the major allergen of fish allergies, eliciting IgE-mediated immune responses. It is a conserved protein in finfish species and highly abundant in the muscle, the largest portion of the food in fish. Two main PARV family clusters have the designations α and β, but only the β is a proven allergen. -PARV is considered a pan-allergen because as it has a vital function, it is widely distributed in wide range of bony fish species and other animals. Attempts to neutralize the allergenicity of proteins in food have been taken, by testing innovative processing methods, such as the High Hydrostatic Pressure (HP). An eco-friendly technology able to preserve the freshness and nutritional benefits of food products, while prolonging their shelf-life. Although HP processing of fish has a relatively small effect on sensory parameters, evidence shows modifications in the proteome and protein solubility of HP treated sea bass (Dicentrarchus labrax, dl) fillets, but the potential influences on human health, regarding the allergenicity is poorly clarified. In this thesis, the effect of HP and/or storage time in the allergenicity potential of -PARV from sea bass fillets was investigated. -PARV was successfully purified from the sarcoplasmic protein fractions of HP (600Mpa and 5 min.) and control fish after isothermal storage for 1 and 11 days and was analyzed by biochemical and biophysical techniques and in silico analysis to predict potential changes in the structural conformation. The results show a prevalence of α-helix in dl-PARV isolated from unprocessed fish fillets and those exposed to HP and time of storage modified the secondary and tertiary protein structure. dl-PARV epitope reactive to IgE/IgE shared a significant portion of residues in a position predicted to be of α-helix. The results suggest that the structural changes caused by HP may alter the allergenicity potential of dl-PARV, since the allergenic epitope seems to depend on protein conformation.
    2022-11-24Master thesis Embargoed access Show more