Determination of Lactoperoxidase in Heat Treated Milk: Comparison of a New Rapid Quantitative Reflectometric Test with a Qualitative Reference Test

摘要

The prototype of a new quantitative reflectometric rapid test for the estimation of lactoperoxidase activity in heat treated milk, Reflectoquant~® peroxidase test, was compared with the official qualitative method of the Swiss Food Manual within the upper temperature range of the denaturation of the enzyme (79-83℃). Raw, ther-mised, pasteurized and UHT milk from the Swiss market, as well as mixtures of thermised and UHT milks were measured. The reflectometric test gave reproducible results in the range of 5-175 U/1 with relative standard deviations around 5%. With a detection limit of 5 U/l this test was more sensitive than the official qualitative method. Some validation data are presented. The Reflectoquant~® peroxidase test is easy to use and suitable for both in dairy plants and laboratories.