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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Commodity Protection and Quality Research » Research » Publications at this Location » Publication #429198
Research Project: Improved Systems-based Approaches that Maintain Commodity Quality and Control of Arthropod Pests Important to U.S. Agricultural Production, Trade and Quarantine

Location: Commodity Protection and Quality Research

Title: A method for the accurate and sensitive detection of natamycin in blueberries by LC-HRMS

Author
item Hall Iv, Wiley
item Saito, Seiya
item Xiao, Chang-Lin

Submitted to: Journal of AOAC International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/24/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Natamycin is a naturally occurring biofungicide that can be used to prevent molds of food. It is currently used mostly in preserved meat, cheese, and wine. As part of the process to register it for more uses (specifically, for use in fresh fruits, like blueberries), the residues (the amount of natamycin left on the fruit as a result of treatment) associated with its use must be determined. For this purpose, we have developed a new analytical method for the efficient, sensitive, and robust quantification of natamycin residues on blueberries. This method will also be useful after the registration of natamycin for use on blueberries and other fresh fruit has been completed, to ensure that natamycin residues are not above the established allowable amounts, and also to ensure that fresh fruits treated with natamycin are getting the proper coverage and a uniform distribution of natamycin within the load of treated commodity.

Technical Abstract: Background: Natamycin is a naturally occurring antimycotic used to prevent mold in a variety of foodstuffs, mainly processed meat, cheese and wine, and more recently certain fresh fruits. Objective: The aim of the present study was to develop and validate a sensitive and selective method for the quantification of natamycin residues in blueberries. Method: A methanolic extraction followed by solid phase extraction clean up and analysis by liquid chromatography coupled to high resolution tandem mass spectrometry validated for the analysis of natamycin residues in blueberries following the SANTE guidelines. Results: The method was validated at 0.025, 0.25 and 11 mg /kg with average recoveries between 86 and 105%, and precision (%RSD) was below 15%. The detection limit for natamycin was below 0.010 mg / kg. Residues of natamycin in treated blueberries were found to range from 1 to 29 mg / kg and remained stable over 4 weeks of storage at 4°C. Conclusions: The LC-HRMS analysis reported here is shown to be an accurate and sensitive method for quantifying natamycin residues in blueberries. Highlights: A method suitable for use in the regulatory and commercial monitoring of natamycin residues in blueberries is developed and presented.