A simple and fast method for the inspection of preservatives in cheeses and cream by liquid chromatography- electrospray tandem mass spectrometry

摘要

In this work, a simplified extraction and short time of analysis method for the simultaneous determination of natamycin, nisin and sorbic acid in cheeses and cream by reverse phase liquid chromatography-electrospray-tandem mass spectrometry was developed. Full validation was performed according to the Commission Decision 2002/657/EC criteria and method applicability was checked on several samples, aiming to inspect their compliance with regulatory limits. The method was linear in the concentration ranges of 0-10 mg kg(-1) (natamycin), 0-25 mg kg(-1) (nisin) and 0 20 mg kg(-1) (sorbic acid). Samples of the three most consumed types of cheese (fresh, pasta filata and ripened) in Brazil and cream (ultra high temperature and pasteurized, 20-30% fat content) were assessed. A surprising rate of non-compliance was observed, especially among ripened grated cheeses, since 80% of samples were above the maximum limit for sorbic acid with an average concentration of 2766.3 +/- 10.8 mg kg(-1). Moreover, a major noncompliance for the cream samples was observed. The proposed method can be applied as an efficient tool for the inspection of preservatives in cheeses and cream. (C) 2015 Elsevier B.V. All rights reserved.