The “Temporal Dominance of Sensations”
- http://www.sciencedirect.com/
Analytical Quality Control Guidelines. Nordic Committee on Food Analysis (NMKL).
The Analytical Quality Control (AQC) Guidelines for the Publication of Analytical Results of Chemical Analysis in Food stuffs is now available on the NMKL:
- www.nmkl.com
Official Methods
2011.05, 2011.07, 2011.16 for folate, Vitamin A, Vitamin B12, in infant formula and adult nutritional are available on OMA online.
- www.eoma.aoac.org
Future programs of the “Stakeholder Panel on Strategic Food Analytical Methods” (SPSFAM) Working Groups of AOAC What happened?
Antioxidant –Fitness for Purpose (FFP) and Standard Method Performance Requirements (SMPRs) were both approved by the SPSFAM Voting Panel. Call for Methods deadline is December 21, 2011. SMPRs posted and comments requested by December 21, 2011.
Flavonoids – Fitness for Purpose (FFP) was approved by the SPSFAM Voting Panel. Call for Methods deadline is December 21, 2011.
Surveillance Methods for Food/Food Ingredients Authenticity (Pure Identity) and Conformity – Advisory Panel to provide priority list of ingredients and materials for next steps and develop a Fitness for Purpose (FFP).
Ingredients – Fitness for Purpose (FFP) to be developed for Vitamins A,D, E and K. SMPRs for Vitamin A, D, and E from the Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) work will be reviewed for applicability to food ingredients.
What’s coming up?
All working groups will be holding teleconferences between now and the AOAC Midyear Meeting. March will be the kickoff for the next working group Packaging Migrants.
Get involved!
If you are a CRO, food company, dietary supplement company and/or an NGO, AOAC needs your expertise. To volunteer, join a working group or for general information, please contact Dawn L. Frazier, CAE, Executive for Scientific Business Development at dfrazier@aoac.org or +1-301-924-7077, ext 117.
Analytical Quality Control. Guidelines for the publication of Analytical Results of Chemical Analyses in Foodstuffs.
NMKL Protocol No.5, Ed. 2011.
- www.nmkl.org
Determination of net content and drained weight of food.
NMKL Method No.55,3. Ed. 2011.
- www.nmkl.org
Which are the news about the detection of “Non-Motile Salmonella” in food microbiology?
Did you know about CHROMagar Salmonella Plus? Detection of Non-Motile Salmonella according to the ISO 6579.
CHROMagar November 2011 Newsletter. >>>
Microbiological Criteria for food evaluation according the Codex Alimentarius Codex Alimentarius. Principles for the Establishment and Application of Microbiological Criteria for Food
- http://www.google.it/
List of the official analytical methods for food according to the NMKL (Nordic Committee on Food Analysis)
The Nordwall certified methods are validated against reference methods given in the EU Directive 2073/2009 and can be used according to the food hygiene regulations. Nordic Committee on Food Analysis. Download from NMKL.
- www.nmkl.org
Methods for As, Cd, Hg and Pb determination in food-stuffs
Methods for As, Cd, Hg and Pb determination in food-stuffs in inductively coupled plasma/mass spectrometry (ICP-MS) after pressure digestion. The method was validated in an inter-laboratory study by NMKL in 2006 and was published as NMKL method No.186 in 2007.
In addition, it is accepted as a standard method in the European Union (EU).
- www.aoac.org
The NMKL -National Veterinary Institute, Oslo, Norway - Nordic Committee of Food Analysis - available methods >>>
- www.nmkl.org
Compact-Dry Nordval / NMKL Approval (National Veterinary Institute)
• Compact-Dry CF Method for Enumeration of Total Coliform >>>
• Compact-Dry EC Method for Enumeration of E. coli and coliform >>>
• Compact-Dry ETB Method foe Enumeration of Enterobacteriaceae >>>
• Compact-Dry TC Method for Enumeration of Total Count >>>
The microbial strains and the related applications for Q.C. in food microbiology
- http://www.microbiologics.com/Food-Quality
Aerobic Plate Count method by FDA
Bacteriological Analytical Manual (BAM) – FDA U.S. Food and Drug Administration
BAM: Microbiological Examination of Canned Food
http://www.fda.gov/Food/ScienceResearch/LaboratoryMethods/
FDA Microbiological Methods
FDA Bacteriological Analytical Manual Online (BAM)
Presents the agency's preferred laboratory procedures for microbiological analyses of foods and cosmetics. AOAC International published previous editions of this manual in a loose-leaf notebook format, and, more recently, on CD-ROM. The complete BAM is now available online and will be updated as needed. A listing of chapters updated since the last hard-copy version (Edition 8, Revision A /1998) can be found in About the Bacteriological Analytical Manual.
Bacillus cereus in liquid, solid foods and swabs with Compact-Dry X-BC >>>
USP Dietary Supplement Compendium.
The compendium includes: (1) USP mission; (2) reference standards and analytical methods; (3) USP-NF dietary supplement monographs; (4) specifications of reagents, test solutions, etc.; (5) safety reviews; (6) supplement regulatory framework; (7) full color illustrations.
- www.usp.org
ISO standards concerning spices and condiments
Spices are often disregarded ingredients for a normal consumer, particularly with their characterization and potential cause of damage to health as contamination source.
Standardisation activity started on 1977 ISO/TC 34 SC/ “Spices, culinary herbs and condiments”).
71 standards are today published.
- UNI EN ISO 676:2009 – Spices and condiments. Botanical nomenclature.
- UNI EN ISO 948:2009 – Spices and condiments. Sampling.
- UNI EN ISO 6571:2009 – Spices, condiments and herbs. Determination of volatile oil content (hydrodistillation method)
- UNI EN ISO 6465:2009 – Cumino (Cuminum cyminum)
- prEN ISO 4720 – Essential oils
- EN ISO 939:2009 – Spices and condiments – Determination of moisture content – Entrainment method (ISO 939:1980)
- prEN ISO 3218 – Essential oils – Principle of nomenclature (ISO 3218:1976)
- EN ISO 3493:2007/prA1 – Vanilla – Vocabulary
- EN ISO 7450:2010 – Ground paprika (Capsicum annuum L.) Specification (ISO 7450:2006)
- EN ISO 7541:2010 – Ground (powdered) paprika – Determination of total natural colouring matter content (ISO 7541:1989)
- EN ISO 2825:2010 – Spices and condiments - Preparation of a ground sample for analysis (ISO 2825:1981).
Methods for microbiological testing of disinfectants efficacy
(A) AOAC – Association of Official Analytical Chemists test methods
| TEST | PURPOSE | AOAC 6.2.02
Official Method 991.47
| Disinfectants testing against Salmonella Choleraesuis
Hard surface carrier Test Method
| AOAC 6.2.03
Official Method 991.48
| Disinfectants testing against Staphylococcus aureus
Hard surface carrier Test Method
| AOAC 6.2.05
Official Method 991.49
| Disinfectants testing against Pseudomonas aeruginosa
Hard surface carrier Test Method
| AOAC 6.2.04
Official Method 955.15
| Disinfectants testing against Staphylococcus aureus
Use-Dilution Method
| AOAC 6.2.01
Official Method 955.14
| Disinfectants testing against Salmonella Choleraesuis
Use-Dilution Method
| AOAC 6.2.06
Official Method 994.02
| Disinfectants testing against Pseudomonas aeruginosa
Use-Dilution Method
| AOAC 6.3.02
Official Method 955.17
| Fungicidal acivity of disinfectants using Trichophyton mentagrophytes
| AOAC 6.3.05
Official Method 966.04
| Sporicidal activity of disinfectants
| AOAC 6.3.06
Official Method 965.12
| Tubercolocidal activity of disinfectants
|
(B) European Committee for Normalization TC216 Committee. Disinfectant Effectiveness Tests – European Tiered Test Approach
| PHASE | TEST TYPE | PURPOSE | Phase 1
| Quantitative suspension test
under unsoiled conditions for basic activity
| To establish that a product has bactericidal and/or fungicidal activity
without regard to specific conditions of intended use.
If the product passes, it qualifies for further testing
| Phase 2
Step 1
| Quantitative suspension test under conditions
representative of practical use
| To establish that a product has bactericidal, and/or fungicidal, and or sporicidal,
and/or virucidal, and/or tubercolocidal, and so forth, activity under conditions
appropriate to its intended use in laboratory conditions.
If the product passes, it qualifies for generic disinfectancy claims.
| Phase 2
Step 2
| Quantitative surface test under conditions
representative of practical use
| Further laboratory test such as hand wash and hand rub tests, and tests on inert
surface to establish that products have microbicidal activity against surface attached
micro-organisms. If the product passes, it qualifies for disinfectancy claims on surfaces.
| Phase 3
| Field test under practical conditions
| Confirmatory test is expected to confirm the findings of Phaeses 1 and 2.
|
(C) British Standards (BS) EN Test Methods
| TEST | PURPOSE | BS EN 1276
| Quantitative suspension test (QST) for the evaluation of bactericidal activity of chemical
disinfectants and antiseptics used in food, industrial, domestic, and institutional areas.
| BS EN 1650
| Quantitative suspension test (QST) for the evaluation of fungicidal activity of chemical
disinfectants and antiseptics used in food, industrial, domestic, and institutional areas.
| BS EN 13704
| Quantitative suspension test (QST) for the evaluation of sporicidal activity of chemical
disinfectants used in food, industrial, domestic, and institutional areas.
| BS EN 13697
| Quantitative non porous surface test for the evaluation of bactericidal and/or fungicidal
activity of chemical disinfectants and antiseptics used in food, industrial, domestic, and institutional areas.
|
Determination of commercial sterility and the presence of viable micro-organisms in canned food Food Directorate - Health Products and Food Branch – Government of Canada – Ottawa, Canada. HPB Method. MFHPB-01 March 2001.
1. Application. 2. Principle. 3: Definition of terms. 4. Collection of samples. 5. Materials and special equipments. 6. Safety precautions. 7. Procedure. 8. Quality Control Procedures. 9. References. 10. Preparation of media.
Diagram 1. Microbiological analysis of the contents of canned foods that are low acid using liquid aerobic / anaerobic Media.
Diagram 2. Microbiological analysis of the contents of canned foods that are acidic or have been acidified using aerobic / anaerobic Media.
Diagram 3. Microbiological analysis of the contents of canned foods using the Direct Plate Method.
URL: www.hc-sc.gc.ca/fn-an/res-rech/analy-meth/microbio/volume2/mfhpb01-01-eng.php - http://www.hc-sc.gc.ca/food-alimentElectronic sheets for the indirect chemical testing of cheese Determination of commercial sterility and the presence of viable micro-organisms in canned foodElectronic sheets for the indirect chemical testing of cheese Salvatore Parisi. Compact Cheese Spreadsheet (C.C.S.) – The practical applications for cheese yield, protein content, chromatographic profile.
Free distribution. drparisi@inwind.it
ISO 11290-1:1996 /Amd 1:2004 Detection Method
Horizontal method for the detection and enumeration of Listeria monocytogenes
ISO 11290-2:1998 /Amd 1:2004 Detection Method
Horizontal method for the detection and enumeration of Listeria monocytogenes
Microbiology of food and animal feeding stuffs – Horizontal method for the detection and enumeration of Listeria monocytogenes
Part 1: Detection method Microbiologia degli alimenti – Metodo orizzontale per la ricerca e la conta di Listeria monocytogenes
Inoculation of a selective primary enrichment medium containing one volume of lithium chloride and half a volume of both acriflavine and nalidixic acid (half Fraser broth), which is also used as a dilution fluid for the test portion.
Incubation of the test portion at 30°C for 24h.
Inoculation of full-strength secondary liquid enrichment medium (Fraser broth) with a culture obtained from primary enrichment.
Incubation of the Fraser broth at 37°C for 48h.
Streak a loopful of the Fraser culture onto surface of plate of ALOA medium (and PALCAM) agar (37°C ± 1 for 48 ± 2 h) so that well isolated colonies will be obtained.
Selection of colonies for confirmation (appropriate morphological, physiological and biochemical tests).
Microbiology of food and animal feeding stuffs – Horizontal method for the detection and enumeration of Listeria monocytogenes
Part 2: Enumeration method Microbiologia degli alimenti – Metodo orizzontale per la ricerca e la conta di Listeria monocytogenes
ISO 11290-2:1998/Amd 1:2004 ISO 11290-2:1998/Amd 1:2004
Preparation of the initial suspension in one of the two diluents described (buffered peptone water or half-Fraser broth).
Resuscitation for 1h at 20°C.
Surface plating, on the solid selective culture medium (ALOA) contained in two Petri dishes, of a specified quantity of the initial suspension.
Preparation of other dishes, under the same conditions, using decimal dilutions of the initial suspension.
Incubation of the dishes at 37°C and examination after 24h and 48h.
Confirmation of presumptive colonies of Listeria monocytogenes with the appropriate tests.
From the number of confirmed colonies, calculation of the number of Listeria monocytogenes per gram or per millilitre of the test sample.
ISO 16649-2:2001
ISO/TS 16649-3:2005
Microbiology of food and animal feeding stuffs
Horizontal method for the enumeration β-glucuronidase-positive Escherichia coli ISO 16649-1:2001 COLONY–COUNT TECHNIQUE AT 44°C USING MEMBRANES AND 5-bromo-4-chloro-3-indolyl- β-D-glucoronic acid.
ISO 16649-2:2001 COLONY–COUNT TECHNIQUE AT 44°C USING 5-bromo-4-chloro-3-indolyl- β-D-glucoronic acid.
ISO/TS 16649-3:2005 MOST PROBABLE NUMBER TECHNIQUE USING 5-bromo-4-chloro-3-indolyl- β-D-glucoronide.
Prepare the test sample in accordance with the specific International Standard appropriate to the product concerned.
ISO 16649-1:2001 Resuscitation: inoculation of a specified quantity of the test sample or initial suspension on to cellulose acetate membranes overlaid on mineral-modified glutamate agar (MMBA), then incubation at 37°C (or 30°C) for 4h.
Inoculation on additional same agar with the same conditions of decimal dilutions from the test sample or the initial suspension. Isolation: transfer of membranes from the resuscitation stage on the mineral-modified glutamate agar to tryptone-bile glucuronide agar (TBX). Incubation at 44°C for 18-24h. Enumeration: calculation of the number of CFU of presumptive Eschericha coli per gram or per millilitre of sample from the number of typical blue CFU. ISO 16649-2:2001
The enumeration of presumptive Escherichia coli requires the successive stage after the preparation of initial suspension using as diluent peptone water (or the specific International Standard dealing with the product under examination). Isolation: inoculation of chromogenic selective culture medium (TBX) with the specified quantity of the initial suspension and dilutions.
Inoculation, under the same conditions, using decimal dilutions of the test sample or of the initial suspension, with 2 plates per dilution.
Incubation of the dishes 18-24h at 44°C and examination to check for the presence of CFU which, from their characteristics, are considered to be Escherichia coli. Enumeration: calculation of the number of colony-forming units (CFU) of presumptive Escherichia coli per gram or per millilitre of sample. ISO/TS 16649-3:2005 Inoculation of three tubes* of liquid selective enrichment medium (minerals modified glutamate medium) with a specified quantity of the test sample if the initial product is liquid, or with a specified quantity of the initial suspension in the case of other products. Then, under the same conditions, inoculation of the medium with decimal dilutions of the test sample or the initial suspension
Incubation of the tubes of medium at 37°C for 24. Examination of the tubes for acid production, signifying lactose fermentation.
For each tube of medium showing acid production, subculture to tryptone bile glucuronide agar.
Incubation of the tryptone bile glucoronide agar at 44°C for 20-24h. Examination of the tryptone bile glucoronide agar for the presence of blue colonies, signifying the presence of β-D-glucoronidase positive Escherichia coli.
Determination of the most probable number of presumptive Escherichia coli by means of the MPN table, according to the number of tubes of medium the subcultures of which have produced blue colonies on tryptone bile glucoronide agar.
*or five tubes
Microbiology of food and animal feeding stuffs
Horizontal method for the enumeration of microorganisms– Colony count technique at 30 °C - ISO 4833:2003
• Preparation of two poured plates, using a specified culture medium, and using a specified quantity of the test sample if the initial product is liquid, or using a specified quantity of a initial suspension in the case of the other products. Preparation of the other pairs of poured plates, under the same conditions, using decimal dilutions of the test sample or the initial suspension.
• Aerobic incubation of plates at 30°C for 72h.
• Calculation of the number of micro-organisms per millilitre or per gram of sample from the number of colonies obtained in selected plates. Microbiology of food and animal feeding stuffsHorizontal method for the enumeration of microorganisms– Colony count technique at 30 °C - ISO 4833:2003 Microbiology of food and animal feeding stuffsHorizontal method for the enumeration of microorganisms– Colony count technique at 30 °C - ISO 4833:2003 Culture medium: enzymatic digestion of casein (5,0g); yeast extract (2,5g); Glucose anhydrosus (C6H12O6) (1,0g); agar (9-18*g); water (1000mL).
* Depending on the gel strength of the agar
ISO-7937:2004 – Horizontal method for Clostridium perfringens count ISO-4832:2006 – Coliform colony count technique at 30°C in Petri plate ISO-4831:2006 – Coliform MPN technique at 30°C Microbiology of food and animal feeding stuffs Horizontal method for the enumeration of Clostridium perfringens - Colony count technique
ISO 7937: 2004
· Petri dishes are inoculated with a specified quantity of the test sample if the initial product is liquid, or a specified quantity of the initial suspension in the case of other products. Further Petri dishes are inoculated, under the same conditions, using decimal dilutions of the test sample or of the initial suspension. A selective medium is added (poured-plate technique) and then an overlay of the same medium. The culture media is Sulfite-cycloserine agar (SC).
· The plates are incubated anaerobically at 37°C for 20 ± 2 h.
· After the specified period of incubation, select all plates containing less than 150 colonies. The characteristic colonies are enumerated.
· The numbers of characteristic colonies are confirmed and the number of C. perfringens per millilitre or per gram of sample is calculated. Microbiology of food and animal feeding stuff
Enumeration of coliforms
MOST PROBABLE NUMBER TECHNIQUE AT 30°C ISO 4831:2006
COLONY COUNT TECHNIQUE AT 30°C ISO 4832:2006
Prepare the test sample in accordance with the specific International Standard appropriate to the product concerned.
ISO 4831:2006
Inoculation of a test portion and/or a series of decimal dilutions of the sample in triplicate into the selective liquid medium prescribed in test tubes containing Durham tubes.
Incubation of the tubes at 30°C for 48h.
From presumed positive tubes, i.e. those tubes showing gas production in the Durham tube in lactose bile brilliant green broth, inoculation on eosin-methylene blue agar.
Incubation of the tubes at 30°C for 24h.
From confirmed positive tubes, i.e. those tubes showing gas production in lactose bile brilliant green broth and characteristic growth on eosin-methylene blue agar, calculation of the number of coliforms per millilitre or per gram of sample (i.e. the MPN) using a table.
ISO 4832:2006
Mixing a defined test portion or a series of decimal dilutions of the sample with the culture medium (i.e. VRBL). in Petri dishes, and covering with a layer of the same medium.
Incubation at 30°C for 24h.
Counting of the characteristic colonies and, if needed, confirmation of colonies by fermentation of lactose, shown by gas production.
Calculation of the number of coliforms per millilitre or per gram of the original sample.
Horizontal method for Bacillus Cereus
Microbiology of food and animal feeding stuffs - Horizontal method for the determination of low numbers of presumptive Bacillus cereus – Most probable number technique and detection method
ISO 21871 (2006) Prepare the test sample in accordance with the specific International Standard dealing with the product concerned. 1) Enrichment in selective liquid medium: inoculation of three tubes of liquid selective enrichment medium: Tryptone soya polymyxin broth (TSPB), with a specified quantity of the primary dilution then, under the same conditions, inoculation with the further dilutions (MPN technique). Prepare a sufficient number of dilutions to ensure that all tubes corresponding to the final dilution will yield a negative result. Incubate the tubes at 30°C for 48h ± 4h.
In case of the enumeration of Bacillus cereus spores only, heat the primary dilution in a water bath set at approximately 80°C for 10 min. 2) Detection: after thorough mixing using a test tube mixing apparatus streak an inoculation loop of culture from each of the tubes onto the surface of polymyxin pyruvate egg yolk mannitol bromothymol blue agar (PEMBA) or mannitol egg yolk polymyxin agar (MYP). Incubate the plates at 37°C (PEMBA) or 30°C (MYP) for 18h to 24h. If the colonies cannot be clearly assessed, continue incubating the plates for up to an additional 24h. 3) Confirmation: biochemical confirmation (glucose fermentation test; Voges-Proskauer test and nitrate reduction test) and microscopic confirmation. 4) Calculation and espression of results: for each dilution of TSPB record the number of tubes in which the presence of Bacillus cereus has been confirmed by biochemical or microscopic reactions. Designate these as positive tubes. Select three consecutive dilutions to obtain the MPN index (use ISO 7218:2007 Table A.1 ). Obtain the MPN of Bacillus cereus per gram of product multiplying the MPN index by the reciprocal of the lowest dilution selected.
Horizontal Method for Campylobacter spp
Microbiology of food and animal feeding stuffs
Horizontal method for the detection of Campylobacter spp. – Part 1: Detection method ISO 10272 – 1 (2006) Prepare the test sample in accordance with the specific International Standard dealing with the product concerned.
In general, the detection of Campylobacter spp. requires the following stages. 1) Enrichment in selective liquid medium: in general, for preparing the initial suspension, introduce a quantity x of the test portion (mass or volume) into a 9x volume of the enrichment medium Bolton broth and homogenizing. Incubation in a microaerobic atmosphere at 37°C for 4 to 6h and then at 41,5°C for 44h ± 4h. 2) Isolation and selection for confirmation: from the cultures obtained, two selective solid media are inoculated:
• modified charcoal cefoperazone deoxycholate agar (mCCD agar);
• any other solid selective medium based on a different principle than mCCD agar.
Incubation at 41,5°C in a microaerobic atmosphere and inspection after 44h ± 4h to detect the presence of colonies presumed to be Campylobacter spp. by their characteristics. 3) Confirmation: subculturing of the colonies presumed to be Campylobacter on the non-selective Columbia blood agar, then confirmation confirmation by means of microscopic examination and appropriate biochemical and growth tests (motility, oxidase etc). Optionally, identification of Campylobacter species by specific biochemical tests and antibiotic sensitivity tests. Horizontal methods for the detection and enumeration of Enterobacteriaceae.
Part 1: detection and enumeration by MPN technique with pre-enrichment
Microbiology of food and animal feeding stuffs – Horizontal methods for the detection and enumeration of Enterobacteriaceae
Part 1: Detection and enumeration by MPN technique with pre-enrichment
ISO 21528-1:2004Prepare the test sample in accordance with the specific International Standard appropriate to the product concerned. 1) Pre-enrichment in non selective medium: buffered peptone water (BPW) is inoculated with the test portion, then incubated at 37°C (or 30°C)1 for 18h ± 2h. 2) Enrichment in selective liquid medium: the enrichment broth [buffered brillant green bile glucose broth (EE broth)] is inoculated with the culture obtained after pre-enrichment, then incubated at 37°C (or 30°C)1 for 24h ± 2h. 3) Isolation and selection for confirmation: a selective solid medium (violet red bile glucose agar) is inoculated with the culture obtained after enrichment in EE broth, then incubated at 37°C (or 30°C)1. It is examined after 24h ± 2h to check for the presence of colonies presumed by their characteristics to be Enterobacteriaceae. 4) Confirmation: colonies of presumptive Enterobacteriaceae are subcultured onto non-selective medium, and confirmed by means of tests for the fermentation of glucose and the presence of oxidase. • Enumeration by the MPN technique.
• Pre-enrichment in non selective medium: a test portion of x g is added to 9 x ml of buffered peptone water (BPW) and homogenized. One more 10-fold dilutions (according to the expected level of contamination) are prepared in BPW. Aliquots (10ml) of this initial dilution are transferred to three tubes. Then 3x1ml of the initial dilution are added to 9ml of BPW and 3x1ml of each further dilution are added to 9ml of BPW. These tubes are incubated at 37°C (or 30°C)1 for 18h ± 2h.
• Enrichment in selective liquid medium: tubes of liquid enrichment broth (EE broth)] are inoculated with each tube of culture obtained after pre-enrichment (at least 3x3). The tubes are incubated at 37°C (or 30°C)1 for 24h ± 2h.
• Isolation and selection for confirmation: a selective solid medium (violet red bile glucose agar) is inoculated with a loop from each of the incubated cultures obtained after enrichment in EE broth, then incubated at 37°C (or 30°C)1. It is examined after 24h ± 2h to check for the presence of colonies presumed by their characteristics to be Enterobacteriaceae
• Confirmation: colonies of presumptive Enterobacteriaceae are subcultured onto non-selective medium, and confirmed by means of tests for the fermentation of glucose and the presence of oxidase
• Calculation: the MPN of Enterobacteriaceae per ml or per gram of the test sample is calculated from the number of confirmed positive tubes using the MPN table.
1 The temperature of 37°C is generally used when the enumeration of Enterobacteriaceae is for a hygienic indicator. Alternatively, a temperature of 30°C can be chosen when the enumeration of Enterobacteriaceae is conducted for technological purposes and includes psychrotrophic Enterobacteriaceae.
*Characteristic colonies are pink to red or purple (with or without precipitation haloes). Horizontal methods for the detection and enumeration of Enterobacteriaceae.
Part 2: Colony Count method. Microbiology of food and animal feeding stuffs – Horizontal methods for the detection and enumeration of Enterobacteriaceae
Part 2: Colony-count method
ISO 21528-2:2004 An initial suspension and decimal dilutions are prepared from the test sample. 1) Isolation: violet red bile agar contained in two Petri dishes (poured-plate technique) is inoculated with a specified quantity of the test sample if the product is liquid, or of the initial suspension in the case of the other products. An overlay of the same medium is added. Other pairs of plates are prepared under the same conditions, using decimal dilutions of the test sample or of the initial suspension. The dishes are incubated at 37°C (or 30°C)1 for 24h ± 2h. 2) Confirmation: subculture of colonies of presumptive Enterobacteriaceae on non-selective medium, and confirmation by means of tests for fermentation of glucose and presence of oxidase. 3) Calculation: the number of Enterobacteriaceae per ml or g of the test sample is calculated from the number of confirmed typical colonies per dish. 1 The temperature of 37°C is generally used when the enumeration of Enterobacteriaceae is for a hygienic indicator. Alternatively, a temperature of 30°C can be chosen when the enumeration of Enterobacteriaceae is conducted for technological purposes and includes psychrotrophic Enterobacteriaceae.
*Characteristic colonies are pink to red or purple (with or without precipitation haloes). Gazzetta Ufficiale Unione Europea L.248 – 17 Set. 2008 – Regolamento n.900/2008 del 16/09/2008. Gazzetta Ufficiale Unione Europea L.249 – 17 Set. 2008 – Regolamento n.904/2008 del 16/09/2008. Alternatives Microbiological Methods Article 5, EU Commission Regulation (EC) 2073/2005, 15 November 2005 on microbiological criteria for foodstuffs: “Specific rules for testing and sampling – The use of alternative analytical methods when the methods are validated against the reference methods in Annex 1, and if a proprietary method, certified by a third party in accordance with the protocol set out in EN/ISO Standard 16140 or other internationally accepted similar protocols is used”. Use of alternative methods can be time and effort saving when checking: • raw materials • new operations • effects of hurdle technology • effects of cleaning • the quality of finished goods in HACCP verification program • compliance with microbiological criteria
Excel Spreadsheet for microbiological food analysis
Download Excel spreadsheet
Procedure no. 5:
Estimation and expression of measurement uncertainty in chemical analysis
Download Excel spreadsheet
Procedure no. 8:
Measurement of uncertainty in microbiological examination of foods.
Download Excel spreadsheet
Procedure no. 9:
Evaluation of results derived from the analysis of certified reference materials.
Download Excel spreadsheet
Procedure no. 20:
Evaluation of results from qualitative methods
Download Excel spreadsheet
Food Fibre Analysis
"TDF" ENZIMATIC METHODS / APPROVALS
| Cereals | Mes-Tris | AOAC 991.43 | AACC 32-07 | | Vegetables | Mes-Tris | AOAC 991.43 | AACC 32-05 | | Vegetables | Phosphates | AOAC 985.29 | AACC 32-05 | | Food | Mes-Tris | AOAC 985.43 | AACC 32-07 | | Food | Phosphates | AOAC 985.29 | AACC 32-05 | | Fruits | Mes-Tris | AOAC 991.43 | AACC 32-07 | | Fruits | Phosphates | AOAC 985.29 | AACC 32-05 |
"SDF/IDF" ENZIMATIC METHODS / APPROVALS
| Cereals | Mes-Tris | AOAC 991.43 | AACC 32-07 | | Cereals | Phosphates | AOAC 991.42 | AACC 32-21 | | Vegetables | Mes-Tris | AOAC 991.43 | AACC 32-07 | | Vegetables | Phosphates | AOAC 991.42 | AACC 32-21 | | Food | Mes-Tris | AOAC 991.43 | AACC 32-07 | | Food | Phosphates | AOAC 991.42 | AACC 32-21 | | Fruits | Mes-Tris | AOAC 991.43 | AACC 32-07 | | Fruits | Phosphates | AOAC 991.42 | AACC 32-21 |
Fiber in Food
AOAC OFFICIAL METHODS OF ANALISYS
| AOAC 985.29 | Total Dietary Fiber if foods
Enzymatic Gravimetric Method
| | AOAC 991.42 | Insoluble Dietary Fiber in Foods and Food Products
Enzymatic-Gravimetric Method (Phosphate buffer) | | AOAC 991.43 | Total Soluble and Insoluble Dietary Fiber in Foods
Enzymatic-Gravimetric Method
(MES-Tris Buffer) | | AOAC 992.16 | Total Dietary Fiber
Enzymatic Gravimetric Method
| | AOAC 993.19 | Soluble Dietary Fiber in Foods and Food Products
Enzymatic-Gravimetric Method (Phosphate Buffer) | | AOAC 993.21 | Total Dietary Fiber in Foods and Food Products with <2% Starch
Non-enzymatic Gravimetric Method | | AOAC 994.13 | Total Dietary Fiber (Determined as Neutral Sugar Residues, Uronic Acid Residues, and Klason Lignin)
Gas Chromatographic Colorimetric Gravimetric Method (Uppsala method) |
AACC APPROVED METHODS OF ANALISYS
| AACC 32.05 | Total Dietary Fiber | | AACC 32.20 | Insoluble Dietary Fiber | | AACC 32.07 | Determination of Soluble, Insoluble and Total Dietary Fiber in Foods and Food Products | | AACC 32.06 | Total Dietary Fiber
Rapid Gravimetric Method | | AACC 32.25 | Total Dietary Fiber Determined as Neutral Sugar Residues, Uronic Acid Residues, and Klason Lignin
(Uppsala method) | | AACC 32.21 | Insoluble and Soluble Dietary Fiber in Oat Products
Enzymatic Gravimetric Method |
From Cereal Food World, 46, 112-126, 2001. |
