Skip to main content
ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Publications at this Location » Publication #344609

Research Project: Reducing Peanut and Tree Nut Allergy

Location: Food Processing and Sensory Quality Research

Title: Acid-etching of zinc metal particles augments adsorption and removal of cashew allergens from extracts

Author
item Li, Yichen - Oak Ridge Institute For Science And Education (ORISE)
item Bren-mattison, Yvette - Biomed Bridge
item Grimm, Casey
item Mattison, Chris

Submitted to: Journal of Food Process Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2018
Publication Date: 5/4/2018
Citation: Li, Y., Bren-Mattison, Y., Grimm, C.C., Mattison, C.P. 2018. Acid-etching of zinc metal particles augments adsorption and removal of cashew allergens from extracts. Journal of Food Process Engineering. 41:4. https://doi.org/10.1111/jfpe.12802.
DOI: https://doi.org/10.1111/jfpe.12802

Interpretive Summary: Metal surfaces can be coated with zinc in a process known as galvanization. Galvanized surfaces are approved by the FDA for use in many food processing steps. Food allergens such as peanuts and tree nuts can cause severe reactions even in very small amounts, and surfaces contaminated with these allergens could pose a serious threat to someone with food allergy. The binding of cashew nut allergens to zinc particles was evaluated. While no binding was detected with untreated zinc particles, protein gel staining and immunoassay revealed that following acid treatment, recruitment of cashew allergens to zinc surfaces was increased. Enzymatic digestion and mass-spectrometric analysis of protein bound to zinc particles revealed the presence of Ana o 2 and Ana o 3 cashew allergen specific peptides. These results indicate that recruitment of cashew allergens to zinc particles was enhanced due to the acid-etching of the zinc surface. The findings suggest the use of galvanized metal surfaces for cashew nut processing is likely safe for most applications, but care should be taken if processing steps occur under acidic conditions.

Technical Abstract: Galvanized metal surfaces are approved by the FDA for use in many food processing steps. Food allergens can cause severe reactions even in very small amounts, and surfaces contaminated with allergens could pose a serious threat. The binding of cashew allergens to zinc particles was evaluated. While no binding was detected with untreated zinc particles, SDS-PAGE and immunoblot revealed that following acid treatment recruitment of cashew allergens to zinc surfaces was increased. Trypsin digestion and LC-MS/MS analysis of protein bound to zinc particles revealed the presence of Ana o 2 and Ana o 3 cashew allergen specific peptides. Recruitment of cashew allergens to zinc particles was enhanced due to the acid-etching of the zinc surface. The findings suggest the use of galvanized metal surfaces for cashew nut processing is likely safe for most applications, but care should be taken if processing steps occur under acidic conditions.