Improved Pretreatment Method for Determination of Nisins A and Z and Monitoring in Cheese Using Liquid Chromatrography-Tandem Mass Spectrometry

Abstract

The peptide nisin produced by Lactococcus lactis subsp. lactis is known to be one of the natural preservatives that are used in various foods including cheese products. This study optimized and validated a liquid chromatographytandem mass spectrometry method for determining nisin A and nisin Z in cheese. Processed and natural cheeses were used for method validation. In addition, this study investigated the content of nisin A and nisin Z in 140 cheese samples comprised of imported and domestic cheese. The nisin A and nisin Z contents of 140 cheese samples were determined. An extraction solution consisting of 0.1 M acetate buffer containing 1 M NaCl (pH 2.0) and methanol (NaCl/MeOH, 1:1v/ v) was the optimal solution for nisin extraction from cheese. The limits of quantification of nisin A and nisin Z were approximately 10.2 and 12.6 μg/kg, respectively. For processed cheese and natural cheese, the recoveries were 80.1-107.3 % for nisin A and 74.4-113.9 % for nisin Z and low coefficients of variation. In monitoring study, nisins A and Z were detected in only three soft processed cheese out of 140 samples. The proposed analysis procedure can be used as an efficient tool for determination of nisin A and nisin Z in cheese using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Antimicrobial effect of nisin in processed cheese - Quantification of residual nisin by LC-MS/MS and development of new growth and growth boundary model for Listeria monocytogenes

“…These differences are in agreement with other studies on the stability of nisin in broth or foods after heat treatments(Davies et al, 1998). For instance,Schneider et al (2011) found the nisin A concentrations determined by LC-MS/MS in processed cheese to be reduced more than 92 % by a heat treatment at 120°C during 30 min Ko et al (2016). also quantified low nisin A concentrations in processed cheese by LC-MS/MS (0.34-0.64 mg/kg) but no information on nisin A concentrations recipes were provided.…”

“…MS/MS method developed in the present study provided recovery values similar to those previously obtained byKo et al (2016); however the present study used an extraction solvent without NaCl as it can interfere with ionization, cause ion suppression and broader peaks in the LC-MS/MS(Sterling et al, 2010). Residual concentrations of nisin A quantified in the present study using LC-MS/MS (0.56-5.28 ppm) were lower than the added concentrations used in the cheese formulations (11.2-12.0 ppm).…”

“…An ISO standard has been published for the quantification of nisin A in cheese by liquid chromatography/mass spectroprometry (LC-MS) and LC-MS/MS (ISO, 2009). This LC-MS/MS method has been used to quantify nisin A in different types of cheeses (Fuselli et al, 2012;Ko et al, 2016;Schneider et al, 2011). However, the relation between concentrations of nisin measured by LC-MS/MS and its antimicrobial activity has not been studied.…”

Novel electrochemical and electrochemiluminescence dual-modality sensing platform for sensitive determination of antimicrobial peptides based on probe encapsulated liposome and nanochannel array electrode

“…Thus, the EC/ECL dual-modality sensing platform for the highly sensitive determination of nisin is established for the first time. Comparison between determination of nisin using different strategies is demonstrated in Supplementary Table S1 (SI) ( 14 , 17 , 52 – 54 ). The LOD obtained by EC detection is lower than that obtained from micellar electrokinetic chromatography (MEKC) ( 54 ), liquid chromatography-mass spectrophotometry/mass spectrophotometry (LC-MS/MS) ( 52 ), or capillary zone electrophoresis (CE) ( 53 ).…”

Optimization of a capillary zone electrophoresis–contactless conductivity detection method for the determination of nisin

“…Chromatographic methods, such as LC–MS , LC–MS/MS , are the major techniques used for the detection and analysis of nisin and other bacteriocins in bacterium media or food matrices . These methods are precise and useful in the analysis when characterization and identification of bacteriocin is performed.…”