NordVal International Certificate 050 issued to HyServe for Compact Dry YM RAPID has been renewed. Compact Dry are ready-to-use dry media sheets comprising culture medium and a cold-soluble gelling agent. The Compact Dry YM RAPID method contains chromogenic medium and selective agents for the detection and enumeration of yeasts and moulds after 3 days of incubation. The method is applicable for a broad range of foods with an aw of >0.95. Like the reference method, it is not intended for mould spores or for heat resistant mould species. See the certificate here. 

NordVal International Certificate 049 issued to Bio-Rad for RAPID’Staph has been renewed. RAPID’Staph is based on an optimised Baird-Parker formula for enumeration of S. aureus. Some Staphylococcus coagulase positive strains can give colonies with a small or no halo after 24 hours of incubation. Additional incubation of 24 hours could be necessary to see the halo. Using RAPID’Staph the typical staphylococci produce gray to black colonies that are shiny and cover with a clear halo. The method is applicable for enumeration of coagulase-positive Staphylococcus (Staphylococcus aureus and other species) in a broad range of foods. See the certificate here.

NordVal International Certificate 022 issued to BioRad for "RAPID´L.mono" has been renewed. The principle of the RAPID’L.mono medium is a chromogenic detection of the Listeria monocytogenes grown on medium containing a selective mixture. RAPID‘L.mono detects Listeria monocytogenes in 24 hours and other Listeria species in 24 and 48 hours. The method is applicable for the enumeration of Listeria monocytogenes and for the detection of other Listeria species in a broad range of food and environmental samples. See the certificate here.

NordVal International Certificate 030 issued to Qualicon for "BAX® System PCR Assay for Salmonella" has been renewed. The Bax® System for detection of Salmonella is targeting a specific bacterial DNA fragment, which is specific for Salmonella and not present in any other bacteria, and hence is an indicator of the presence of Salmonella. The method is applicable for the detection of Salmonella spp. in a broad range of foods, animal feed and environmental samples. See the certificate here.

NMKL /NordVal International and AOAC International have signed an Agreement of Cooperation that will streamline the process for test kit companies seeking recognition from NordVal International and AOAC simultaneously.

The new agreement allows the two organizations and their respective certification programmes to jointly develop and use common evaluation protocols and select independent testing laboratories.

The goal of the cooperative agreement is to reduce the economic barrier imposed by requiring separate studies. Joint protocols mean method developers will be able to conduct testing once at one laboratory, and the data will be applicable to both AOAC and NMKL. Each organization will conduct reviews, render decisions on approvals of methods and issue certificates.

NordVal International receives many applications and, consequently, regularly seeks members to its technical committee. If you are interested in contributing to its work, ref. below-mentioned description of functions, please contact the NMKL secretariat. To see description of functions please click here

NMKL method No. 202, "Methylmercury: determination by isotope dilution GC-ICPMS in foodstuffs", describes the quantitative determination of mono-methylmercury (MMHg) (10-5000 µg/kg dry weight) in mainly marine biota samples. The principle of the method is that the sample is spiked with an appropriate amount of Hg isotope-enriched MMHg and extracted. After derivatisation the sample is analysed using GC-ICPMS. The GC separates the different mercury species before MMHg is atomised and ionised in the high temperature of the ICP. The ions are extracted from the plasma, and in a mass spectrometer the ions are separated by their mass/charge ratio.

NMKL method 183 describes sensory quality control of drinking water. Water samples are tested against flavour-neutral reference water. If there are deviations, these are registered and a remark is given according to the nomenclature list in the method. The method is updated to now also include test settings and parameters for appearance. In addition, references have been updated.

NMKL 151 Presumptive Shigella spp. Detection in foods has been reintroduced and updated.

The presence of Shigella in food and the environments is normally of human fecal origin. Shigella is host-specific for higher primates, including humans. Shigella is usually present in foods in low number due to their poor ability to compete. Consequently, they are notoriously difficult to detect in foods. The infectious dose is low, and only 10-100 Shigella are needed to cause infection. Due to the low infectious dose, cross contamination from infected humans to foods and further on to more persons can occur, for example through handling of foods. Person-to-person contamination can also occur. It has been shown that Shigella can survive in weeks and months in or on different foodstuffs.

In this updated method, a step to reduce background flora and ease the isolation of Shigella for some matrices has been introduced. In addition, recommendation regarding which plates to use has been added. This method can be used for subsequent isolation of Shigella spp. after using NMKL 174, 2016, for detection of the virulence factor ipaH in enrichment broth. NMKL 174 can also be used for detection of ipaH in presumptive colonies.

When the result of a chemical analysis is presented in an analytical report it is recommended that it should always be reported as a numerical result. For the result to be complete, the measurement uncertainty of the analysis should also be included. In many cases, a result can be very hard to interpret unless accompanied by its uncertainty.

In this updated version of the procedure, guidance on how to handle bias / systematic errors in relation to measurement uncertainty is included. The principles described in Nordtest TR 537 for environmental analyzes have been introduced in the NMKL procedure and examples showing how these calculations are to be performed have been added. Whether one can or should correct for systematic errors is a complex issue, and a new section has been added to explain his. Additionally, minor restructuration and update of references have been undertaken.

A scandinavian version of this 3rd edition will follow.

NMKL method No. 203 describes the determination of sodium content in foodstuffs by capillary electrophoresis (CE). The CE method is quick and needs both very little sample handling and low amount of solvents. It is applicable to various matrices such as bread, vegetables and meat products. The salt content is calculated from the sodium content with the formula: salt = 2.5 x sodium.

Sodium is extracted from sample and analysed by CE with diode array detector. The minimum content of sodium that can be detected and quantified is 0.03 g/100 g.