Overview
EN ISO 9233-2:2018 (ISO 9233-2 | IDF 140-2:2018) specifies a high-performance liquid chromatographic (HPLC) method for measuring natamycin in cheese, cheese rind and processed cheese. The standard covers quantitative determination of natamycin mass fraction in product matrices at levels above 0.5 mg/kg and the surface-area-related natamycin mass on cheese rinds above 0.03 mg/dm². Published by CEN/ISO in 2018, this document updates earlier editions and is intended for laboratories performing routine and regulatory analyses.
Key Topics
- Analytical principle: extraction of natamycin from cheese matrices followed by separation and quantification using HPLC (high-performance liquid chromatography).
- Scope and limits: applicable for natamycin mass fractions > 0.5 mg/kg and surface-area-related mass > 0.03 mg/dm² (cheese rind).
- Sampling and sample preparation: guidance on representative sampling, preparation of test portions for rind and interior, and generating test solutions prior to HPLC analysis.
- Reagents and apparatus: lists required solvents, standards and chromatographic equipment (HPLC) needed to perform the method.
- Calibration and quantification: preparation of calibration graphs, determination and reporting of detection/quantification limits, and handling of low natamycin contents.
- Calculation and expression of results: procedures to calculate mass fraction, surface-area-related mass, corrections and reporting formats.
- Performance characteristics: data on method precision including repeatability, reproducibility and interlaboratory trial results.
- Quality and reporting: requirements for test reports and examples provided in informative annexes.
Applications and Users
- Food testing laboratories: routine monitoring of natamycin levels in cheeses and processed cheese products using a validated HPLC procedure.
- Dairy industry QA/QC: in-house quality control to verify proper application of natamycin on rinds and compliance with product specifications.
- Regulatory authorities and food safety labs: enforcement of legal limits for natamycin as a permitted antifungal additive/preservative.
- Third-party conformity assessment: independent testing for certification, import/export checks and market surveillance.
Practical benefits include standardized, reproducible quantification across laboratories, clear procedures for sampling and calculation, and defined performance criteria to support compliance and product safety decisions.
Related Standards
- Part of the ISO 9233 / IDF 140 series on natamycin analysis; consult the series for other parts and complementary methods (e.g., alternative analytical techniques or sampling standards).
- Cited as EN ISO 9233-2:2018 for European national adoption and harmonized use across CEN member countries.
