title: Shrimp tropomyosin retains antibody reactivity after exposure to acidic condition.
abstract: BACKGROUND
  Although shrimp can be found in certain high acid food matrices, the allergenic capacity of shrimp tropomyosin exposed to low pH condition has not been fully clarified. Thus, a model marinade comprising white vinegar adjusted to different pH was used to determine the effects of acid-induced denaturation on the immunoreactivity of tropomyosin.
  
  
  RESULTS
  Whole shrimp experienced either swelling or shrinkage after marination depending on the vinegar pH and the final muscle pH. The extractability of soluble myofibrillar proteins was reduced significantly among shrimp marinated in vinegar at pH 1.0-3.5, and a substantial amount of tropomyosin was retained in the insoluble pellets. Consequently, the immunoglobulin E (IgE)-binding capacity of tropomyosin was significantly lower in the soluble protein fraction of shrimp marinated at pH 1.0-3.5 compared with samples marinated at pH 4.8 and control. However, tropomyosin in the insoluble protein fraction of all marinated shrimp showed strong IgE-binding capacity at all marinating conditions.
  
  
  CONCLUSIONS
  Thus, tropomyosin in shrimp exposed to low pH condition retained its allergenic capacity owing to the conservation of its linear epitopes. Analysis of the insoluble protein fraction was crucial for the accurate determination of the effect of low pH condition on the immunoreactivity of this allergen. © 2017 Society of Chemical Industry.
authors.affiliation: Food Science and Human Nutrition, School of Food and Agriculture, University of Maine, Orono, ME, USA.
authors.forename: Adeseye
authors.initials: A
authors.lastname: Lasekan
authors.affiliation: Food Science and Human Nutrition, School of Food and Agriculture, University of Maine, Orono, ME, USA.
authors.forename: Hanjuan
authors.initials: H
authors.lastname: Cao
authors.affiliation: US Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, LA, USA.
authors.forename: Soheila
authors.initials: S
authors.lastname: Maleki
authors.affiliation: Food Science and Human Nutrition, School of Food and Agriculture, University of Maine, Orono, ME, USA.
authors.forename: Balunkeswar Balu
authors.identifier: http://orcid.org/0000-0001-5831-5193
authors.initials: BB
authors.lastname: Nayak
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000818:Animals; D060829:Arthropod Proteins / Q000737:chemistry* / Q000276:immunology*; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D006863:Hydrogen-Ion Concentration; D007073:Immunoglobulin E / Q000276:immunology*; D033561:Penaeidae / Q000737:chemistry / Q000276:immunology*; D014335:Tropomyosin / Q000737:chemistry* / Q000276:immunology*
chemical_list: D060829:Arthropod Proteins; D000939:Epitopes; D014335:Tropomyosin; D007073:Immunoglobulin E; D019342:Acetic Acid
keywords: IgE binding; allergen; denaturation; marination; shrimp; tropomyosin