Determination of hen’s egg white lysozyme in milk and cheese : interlaboratory collaborative study

This article presents the results of an international collaborative study conducted to validate previous technical specifications for the measurement of lysozyme in cheese. The work proposes minor modifications to the method, which will be published as an international standard (ISO 27105|IDF 216) for the determination of hen's egg white lysozyme in milk and milk products by HPLC. The method is suitable for measuring low levels of hen's egg white lysozyme with a quantification limit of 10 mg/kg. The repeatability is 8.4% (95% CI: 6.7–9.3%) and the reproducibility 34.7% (95% CI: 20.8–59.0%).