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ARS Home » Southeast Area » New Orleans, Louisiana » Southern Regional Research Center » Food Processing and Sensory Quality Research » Research » Publications at this Location » Publication #425121
Research Project: Reducing the Development and Severity of Allergy to Peanuts and Tree Nuts

Location: Food Processing and Sensory Quality Research

Title: Separation of intact cashew nut proteins by reversed-phase liquid chromatography for improved allergen resolution

Author
item Blackwell, Deidre
item McBride, Jane
item Dupre, Rebecca
item Priddy, Daniel

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2025
Publication Date: 8/18/2025
Citation: Blackwell, D.L., Mcbride, J.K., Dupre, R.A., Priddy, D.M. 2025. Separation of intact cashew nut proteins by reversed-phase liquid chromatography for improved allergen resolution. Journal of Agricultural and Food Chemistry. https://doi.org/10.1021/acs.jafc.5c05463.
DOI: https://doi.org/10.1021/acs.jafc.5c05463

Interpretive Summary: Cashews are one of the 9 major food allergens recognized by the U.S. FDA. We developed a method to improve separation of the most abundant cashew protein allergens. Typically, proteins are separated based on size into a few protein groups using gel electrophoresis. By liquid chromatography, these few protein groups are expanded to show multiple protein variants allowing for better potential identification of the proteins and their relationship to food allergy reactions. Knowing the specific protein allergen form as well as their functions can help with determine the best actions to reduce the occurrences of peanut and tree nut allergic reactions.

Technical Abstract: Intact cashew nut allergenic proteins were separated using a reversed-phase liquid chromatography (RP-HPLC) method to improve resolution over sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS-PAGE) separation. Cashew proteins were successfully extracted with solutions containing SDS or guanidine hydrochloride (Gdn-HCl) in reduced and non-reduced conditions. Through evaluation by SDS-PAGE and RP-HPLC, reduced extracts were shown to be more stable over 14 days than non-reduced extracts. Major allergens (Ana o 2 and Ana o 3) were identified in the RP-HPLC method by fraction collection and confirmed by SDS-PAGE and liquid chromatography tandem mass spectrometry (LC-MS/MS). The RP-HPLC method was repeatable (peak area %RSD range: 0.5 – 1.0%) and showed good linearity of peak groups (R2 range: 0.9991 – 0.9998) for potential usage for quantitation. The methods were applicable to cashew flour, milk, and butter samples as well as recombinant Ana o 3 demonstrating profiling or fingerprinting abilities for cashew products with varied genetics and forms.