Infokiri

REFERENCE MATERIAL DATASHEET 1 (4) File number: Dnr 2025/02935

Reference Material Datasheet Version: 1.0

Issue date: 2025-08-01

Designation: RM Food 2025:8

Batch no: 406

Date of production: 2024-06-26

Manufacturer: Swedish Food Agency, Sweden

Storage: –18 °C or lower (but not lower than –55 °C)

Batch expiry date: 2026-12-31

Manufacturer and contact information

Swedish Food Agency

Company name Swedish Food Agency (Livsmedelsverket)

Department Unit for Microbiology

Address P.O. Box 622

Post code SE-75126

City Uppsala

Country Sweden

Telephone +46 18 17 55 00

E-mail [email protected]

Intended use

This reference material is designed for internal quality control of analytical work at food microbiology laboratories. After reconstitution, the test material can be used for control of quantitative food microbiology analyses, as well as for direct or indirect quality control of microbiological media.

Content

Table 1. Microorganisms included in RM Food 2025:8

Microorganism Strain*

Penicillium roqueforti SLV-510

Cladosporium cladosporioides SLV-488

Saccharomyces cerevisiae SLV-375 * Internal strain identification number, Swedish Food Agency

Quality control

The reference material has been tested for homogeneity at the Swedish Food Agency. No statistically relevant difference has been observed between vials.

REFERENCE MATERIAL DATASHEET

2 (4)

File number: Dnr 2025/02935

Property values

Table 2. Quality control of RM Food 2025:8. The results are from analysis of 10 individual vials, and are valid for a reconstitution volume of 104 ml. All values are expressed in log10 cfu ml-1.

Analysis xRM sRM uRM Acceptance limits Method

Yeasts 3.12 0.13 0.38 2.35 – 3.88 NMKL 98:2005 (DG18, 7 days at 25 °C)

Moulds 3.22 0.06 0.36 2.50 – 3.94 NMKL 98:2005 (DG18, 7 days at 25 °C)

xRM: Property value, to be used for start-up control chart.

sRM: Standard deviation of the property value, can be used for start-up control chart.

uRM: Standard uncertainty of the property value (includes uncertainty contributions from characterisation, homogeneity, transportation and method differences).

The lower/upper acceptance limits are calculated as: xRM ± 2 * uRM (expanded uncertainty at a 95 % confidence interval, with k = 2)

Commutability

The values in Table 2 are calculated with and apply for the respective methods specified. They are in general applicable to other similar methods, but results may differ from those determined during the quality control at the Swedish Food Agency. The standard uncertainties (uRM) of the property values include uncertainty contributions from method differences (sR), which are calculated from historical distributions of results from different methods on PT samples with a similar composition. The standard uncertainties and acceptance limits can thus in most cases be considered applicable for comparable microbiological methods.

Traceability

Homogeneity, property values, standard deviations and control limits are calculated in accordance with ISO 17034 and ISO Guide 35. All values are metrologically traceable to the respective strains in the Swedish Food Agency’s internal culture collection (Table 1).

Preparation of simulated food sample

Reconstitute the vial content according to the instructions on the last page.

Please note that the final 104 ml corresponds to the undiluted sample to be analysed.

The Swedish Food Agency uses peptone water (0.1 %) with NaCl (0.85 %) as diluent. Laboratories are however advised to use the same diluent as they normally use for the analysis of yeasts and moulds.

Analyses

The analyses should be performed in accordance with the methods used by the individual laboratory.

Control charts

Instructions for the construction of control charts are available at our website: www.livsmedelsverket.se/RM-micro

REFERENCE MATERIAL DATASHEET

3 (4)

File number: Dnr 2025/02935

Approved by

Jonas Ilbäck Jonas Ilbäck RM Production Coordinator

REFERENCE MATERIAL DATASHEET

4 (4)

File number: Dnr 2025/02935

Sample preparation of freeze-dried cultures in glass vial (RM Food)

1. Twist the flap on the aluminium cap in the direction of the arrow.

2. Remove the aluminium cap.

3. Remove the rubber plug.

4. Carefully burn the opening of the vial over a gas flame.

5. Add 1 ml diluent with a sterile pipette.

6. Let the content dissolve (1-5 minutes).

7. Using a sterile Pasteur pipette, transfer the suspension to a sterile bottle containing 100 ml room temperature diluent.

8. Add another 1 ml and carefully rinse the walls of the vial with the Pasteur pipette.

9. Transfer the suspension to the bottle containing 100 ml diluent.

10. Repeat steps 8 and 9 two more times with the same Pasteur pipette.

11. After thorough intermittent mixing, the 104 ml sample is ready for analysis.

12. Perform the analyses within 60 minutes.*

* From experience, for analysis of moulds more accurate results are often obtained if the final 104 ml sample is allowed to rest for 30 minutes (followed by a new mixing) prior to analysis.

REFERENCE MATERIAL DATASHEET 1 (4) File number: Dnr 2025/02935

Reference Material Datasheet Version: 1.0

Issue date: 2025-08-01

Designation: RM Food 2025:8

Batch no: 406

Date of production: 2024-06-26

Manufacturer: Swedish Food Agency, Sweden

Storage: –18 °C or lower (but not lower than –55 °C)

Batch expiry date: 2026-12-31

Manufacturer and contact information

Swedish Food Agency

Company name Swedish Food Agency (Livsmedelsverket)

Department Unit for Microbiology

Address P.O. Box 622

Post code SE-75126

City Uppsala

Country Sweden

Telephone +46 18 17 55 00

E-mail [email protected]

Intended use

This reference material is designed for internal quality control of analytical work at food microbiology laboratories. After reconstitution, the test material can be used for control of quantitative food microbiology analyses, as well as for direct or indirect quality control of microbiological media.

Content

Table 1. Microorganisms included in RM Food 2025:8

Microorganism Strain*

Penicillium roqueforti SLV-510

Cladosporium cladosporioides SLV-488

Saccharomyces cerevisiae SLV-375 * Internal strain identification number, Swedish Food Agency

Quality control

The reference material has been tested for homogeneity at the Swedish Food Agency. No statistically relevant difference has been observed between vials.

REFERENCE MATERIAL DATASHEET

2 (4)

File number: Dnr 2025/02935

Property values

Table 2. Quality control of RM Food 2025:8. The results are from analysis of 10 individual vials, and are valid for a reconstitution volume of 104 ml. All values are expressed in log10 cfu ml-1.

Analysis xRM sRM uRM Acceptance limits Method

Yeasts 3.12 0.13 0.38 2.35 – 3.88 NMKL 98:2005 (DG18, 7 days at 25 °C)

Moulds 3.22 0.06 0.36 2.50 – 3.94 NMKL 98:2005 (DG18, 7 days at 25 °C)

xRM: Property value, to be used for start-up control chart.

sRM: Standard deviation of the property value, can be used for start-up control chart.

uRM: Standard uncertainty of the property value (includes uncertainty contributions from characterisation, homogeneity, transportation and method differences).

The lower/upper acceptance limits are calculated as: xRM ± 2 * uRM (expanded uncertainty at a 95 % confidence interval, with k = 2)

Commutability

The values in Table 2 are calculated with and apply for the respective methods specified. They are in general applicable to other similar methods, but results may differ from those determined during the quality control at the Swedish Food Agency. The standard uncertainties (uRM) of the property values include uncertainty contributions from method differences (sR), which are calculated from historical distributions of results from different methods on PT samples with a similar composition. The standard uncertainties and acceptance limits can thus in most cases be considered applicable for comparable microbiological methods.

Traceability

Homogeneity, property values, standard deviations and control limits are calculated in accordance with ISO 17034 and ISO Guide 35. All values are metrologically traceable to the respective strains in the Swedish Food Agency’s internal culture collection (Table 1).

Preparation of simulated food sample

Reconstitute the vial content according to the instructions on the last page.

Please note that the final 104 ml corresponds to the undiluted sample to be analysed.

The Swedish Food Agency uses peptone water (0.1 %) with NaCl (0.85 %) as diluent. Laboratories are however advised to use the same diluent as they normally use for the analysis of yeasts and moulds.

Analyses

The analyses should be performed in accordance with the methods used by the individual laboratory.

Control charts

Instructions for the construction of control charts are available at our website: www.livsmedelsverket.se/RM-micro

REFERENCE MATERIAL DATASHEET

3 (4)

File number: Dnr 2025/02935

Approved by

Jonas Ilbäck Jonas Ilbäck RM Production Coordinator

REFERENCE MATERIAL DATASHEET

4 (4)

File number: Dnr 2025/02935

Sample preparation of freeze-dried cultures in glass vial (RM Food)

1. Twist the flap on the aluminium cap in the direction of the arrow.

2. Remove the aluminium cap.

3. Remove the rubber plug.

4. Carefully burn the opening of the vial over a gas flame.

5. Add 1 ml diluent with a sterile pipette.

6. Let the content dissolve (1-5 minutes).

7. Using a sterile Pasteur pipette, transfer the suspension to a sterile bottle containing 100 ml room temperature diluent.

8. Add another 1 ml and carefully rinse the walls of the vial with the Pasteur pipette.

9. Transfer the suspension to the bottle containing 100 ml diluent.

10. Repeat steps 8 and 9 two more times with the same Pasteur pipette.

11. After thorough intermittent mixing, the 104 ml sample is ready for analysis.

12. Perform the analyses within 60 minutes.*

* From experience, for analysis of moulds more accurate results are often obtained if the final 104 ml sample is allowed to rest for 30 minutes (followed by a new mixing) prior to analysis.