Vitamin B12 - Revision history

https://eurofir-wiki.metrofood-services.eu/index.php?action=history&feed=atom&title=Vitamin_B12 Vitamin B12 - Revision history 2026-04-15T10:21:15Z Revision history for this page on the wiki MediaWiki 1.32.1 https://eurofir-wiki.metrofood-services.eu/index.php?title=Vitamin_B12&diff=888&oldid=prev Admin: 4 revisions imported 2019-05-09T13:33:11Z

<p>4 revisions imported</p> <table class="diff diff-contentalign-left" data-mw="interface"> <tr class="diff-title" lang="en-GB"> <td colspan="1" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="1" style="background-color: #fff; color: #222; text-align: center;">Revision as of 13:33, 9 May 2019</td> </tr><tr><td colspan="2" class="diff-notice" lang="en-GB"><div class="mw-diff-empty">(No difference)</div> </td></tr></table>

Admin https://eurofir-wiki.metrofood-services.eu/index.php?title=Vitamin_B12&diff=887&oldid=prev Admin: Protected "Vitamin B12" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite)) 2018-01-08T12:33:15Z

<p>Protected "<a href="/index.php/Vitamin_B12" title="Vitamin B12">Vitamin B12</a>" ([Edit=Allow only administrators] (indefinite) [Move=Allow only administrators] (indefinite))</p> <table class="diff diff-contentalign-left" data-mw="interface"> <tr class="diff-title" lang="en-GB"> <td colspan="1" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="1" style="background-color: #fff; color: #222; text-align: center;">Revision as of 12:33, 8 January 2018</td> </tr><tr><td colspan="2" class="diff-notice" lang="en-GB"><div class="mw-diff-empty">(No difference)</div> </td></tr></table>

Admin https://eurofir-wiki.metrofood-services.eu/index.php?title=Vitamin_B12&diff=886&oldid=prev Admin at 08:51, 23 November 2017 2017-11-23T08:51:04Z

<p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en-GB"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 08:51, 23 November 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l93" >Line 93:</td> <td colspan="2" class="diff-lineno">Line 93:</td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* Greenfield and Southgate discuss the criteria for analytical performance and quality of analytical data in their book.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>* Greenfield and Southgate discuss the criteria for analytical performance and quality of analytical data in their book.</div></td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>** [ftp://ftp.fao.org/docrep/fao/008/y4705e/y4705e00.pdf Greenfield H, Southgate DAT. 2003. Food composition data <del class="diffchange diffchange-inline">? </del>production, management and use. Elsevier Applied Science, London, UK.]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>** [ftp://ftp.fao.org/docrep/fao/008/y4705e/y4705e00.pdf Greenfield H, Southgate DAT. 2003. Food composition data <ins class="diffchange diffchange-inline">- </ins>production, management and use. Elsevier Applied Science, London, UK.]</div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Certified Reference Materials/Standard Reference Material ===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Certified Reference Materials/Standard Reference Material ===</div></td></tr>  </table>

Admin https://eurofir-wiki.metrofood-services.eu/index.php?title=Vitamin_B12&diff=885&oldid=prev Admin at 07:41, 21 November 2017 2017-11-21T07:41:17Z

<p></p> <table class="diff diff-contentalign-left" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en-GB"> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 07:41, 21 November 2017</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l1" >Line 1:</td> <td colspan="2" class="diff-lineno">Line 1:</td></tr> <tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><br /> <br /> Figure 1. R-cobalamin<br /> <br /> R = -CN/-OH/-H<sub>2</sub>O/-NO<sub>2</sub>/-5'-deoxyadenosyl/-CH<sub>3</sub></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><br /> </div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">[[File:B12.jpg]]</ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> <br /> Figure 1. R-cobalamin<br /> <br /> R = -CN/-OH/-H<sub>2</sub>O/-NO<sub>2</sub>/-5'-deoxyadenosyl/-CH<sub>3</sub></div></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Cyanocobalamin: C<sub>63</sub>H<sub>88</sub>CoN<sub>14</sub>O<sub>14</sub>P, Mw = 1355,38 g/mol<br /></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Cyanocobalamin: C<sub>63</sub>H<sub>88</sub>CoN<sub>14</sub>O<sub>14</sub>P, Mw = 1355,38 g/mol<br /></div></td></tr>  </table>

Admin https://eurofir-wiki.metrofood-services.eu/index.php?title=Vitamin_B12&diff=884&oldid=prev Admin: Created page with "<br /> <br /> Figure 1. R-cobalamin<br /> <br /> R = -CN/-OH/-H<sub>2</sub>O/-NO<sub>2</sub>/-5'-deoxyadenosyl/-CH<sub>3</sub> Cyanocobalamin: C<sub>63</sub>H<sub>88</sub..." 2017-05-12T15:31:18Z

<p>Created page with "<br /> <br /> Figure 1. R-cobalamin<br /> <br /> R = -CN/-OH/-H<sub>2</sub>O/-NO<sub>2</sub>/-5'-deoxyadenosyl/-CH<sub>3</sub> Cyanocobalamin: C<sub>63</sub>H<sub>88</sub..."</p> <p><b>New page</b></p><div><br /> <br /> Figure 1. R-cobalamin<br /> <br /> R = -CN/-OH/-H<sub>2</sub>O/-NO<sub>2</sub>/-5'-deoxyadenosyl/-CH<sub>3</sub><br /> <br /> Cyanocobalamin: C<sub>63</sub>H<sub>88</sub>CoN<sub>14</sub>O<sub>14</sub>P, Mw = 1355,38 g/mol<br /><br /> <br /> <br /> Vitamin B<sub>12</sub> consists of a group of compounds that have similar vitamin activity than cyanocobalamin, e.g. cyanocobalamin, hydroxocobalamin, aquocobalamin and nitritocobalamin. Methylcobalamin and 5'-deoxyadenosylcobalamin are the coenzyme forms of vitamin B<sub>12</sub>.<br /> <br /> Synonyms for vitamin B<sub>12</sub>:<br /> <br /> * cobalamin, cyanocobalamin, antipernicious anemia factor<br /> <br /> <br /> -----<br /> <br /> === Standard ===<br /> <br /> * No EN standard available.<br /> <br /> * [http://www.aoac.org/omarev1/952_20.pdf AOAC 952.20] Cobalamin (Vitamin B12 Activity) in Vitamin Preparations<br /> ** microbiological assay according to [http://www.aoac.org/omarev1/960_46.pdf AOAC 960.46]<br /> <br /> === Method indicator ===<br /> <br /> * ''Name''<br /> * ''Code''<br /> <br /> === Scope ===<br /> <br /> AOAC 952.20 specifies a method for the determination of cobalamin (vitamin B<sub>12</sub> activity) from vitamin preparations, but AOAC has recommended the method for all food matrices. Cobalamin is determined by microbiological assay using ''Lactobacillus delbrueckii'' (''leichmannii'') ATCC 7830. The microbiological assay is performed according to the official method AOAC 960.46.<br /> <br /> === Principle ===<br /> <br /> Vitamin B<sub>12</sub> is extracted and determined by microbiological assay using either titrimetric or turbidimetric method.<br /> <br /> === Key steps ===<br /> <br /> ==== Extraction<br /> ====<br /> <br /> * Phosphate buffer containing reducing agent (e.g. metabisulfite or ascorbic acid) is added to the sample to extract the vitamin B<sub>12</sub> active compounds.<br /> * The sample is homogenised in the extraction solution.<br /> * The extraction includes heat treatment<br /> ** autoclaving at 121 °C, 10 min<br /> * pH is adjusted to 4,5.<br /> * The sample solution is diluted with water and filtered. <br /> <br /> ==== '''Microbiological assay''' ====<br /> <br /> '''Preparation of test tubes''' <br /> <br /> * Microbiological assay is performed using test tubes.<br /> * All of the blanks, standard solutions and samples are prepared at least in duplicates.<br /> * Both an uninoculated and inoculated blank are prepared.<br /> * Test tubes having four different dilution levels of sample solutions are prepared.<br /> * Water and basal medium stock solution are added to test tubes.<br /> ** The total volume of the solution in every test tube is 10 ml.<br /> * Test tubes are sterilised prior to inoculation of test tubes.<br /> ** The uninoculated blanks are the only test tubes that are not inoculated.<br /> <br /> '''Determination by titrimetric method'''<br /> <br /> * Tubes are incubated at 30-40 °C for 72 h.<br /> * Contents of test tubes are titrated using bromothymol blue indicator.<br /> ** Titration may also be done using potentiometric measurement.<br /> <br /> <br /> '''Determination by turbidimetric method'''<br /> <br /> * Tubes are incubated at 30-40 °C for 16-24 h.<br /> * Photometer is calibrated with standard stock solutions.<br /> ** Calibration curve is formed by plotting the transmittance (%) for every dilution level against the corresponding content (mg dry weight).<br /> * The test tube solutions are transferred to optical cells and transmittance is measured photometrically.<br /> * Spectrometer is set to 540-660 nm and adjusted to 100 % transmission for uninoculated blanks.<br /> * After achieving a steady state, absorbance of test tubes are read. <br /> <br /> ==== Calculation ====<br /> <br /> * The vitamin B<sub>12</sub> content/ml of the test solution is calculated for each dilution level. <br /> * Average of values is calculated taking into account such samples that do not vary by more than 10 % from the average.<br /> <br /> <br /> <br /> <br /> <br /> -----<br /> <br /> === Remarks ===<br /> <br /> * The samples must be protected from excessive exposure to light.<br /> * To maintain adequate activity of the test organism, regular transfers should be done.<br /> * The test organism is sensitive to many cleansing agents.<br /> ** Suitable detergents should be used to cleanse laboratory glassware.<br /> * Turbidimetric method cannot be used if samples contain high amount of color.<br /> <br /> === Criteria for analytical performance and analytical quality control ===<br /> <br /> * Greenfield and Southgate discuss the criteria for analytical performance and quality of analytical data in their book.<br /> ** [ftp://ftp.fao.org/docrep/fao/008/y4705e/y4705e00.pdf Greenfield H, Southgate DAT. 2003. Food composition data ? production, management and use. Elsevier Applied Science, London, UK.]<br /> <br /> === Certified Reference Materials/Standard Reference Material ===<br /> <br /> * [https://metrofood-wiki.foodcase-services.com/index.php?title=Reference+materials+-+B12 link to detailed data]<br /> <br /> === Proficiency testing schemes ===<br /> <br /> Here are listed some completed, on-going and/or upcoming proficiency testing schemes concerning vitamin B<sub>12</sub>:<br /> <br /> [http://www.dla-lvu.de/english/DLA%20Programm%202011%20english.html DLA - Dienstleistung Lebensmittel Analytik GbR: 27/2011 Food Supplement I: Vitamins B1, B2, B6, B12 and Folic Acid]<br /> <br /> [http://www.slv.se/upload/dokument/rapporter/Kvalitetssakring_lab/2008/2008_22_National_Food_Administration_proficiency_testing_eng.pdf Livsmedelsverket, National Food Agency of Sweden - Report 22 (2008) Vitamins in Foods - Round V-6]<br /> <br /> [http://otis.jtlnet.com/~proficie/proficiencytesting.com.au/documents/651.pdf PTA - Proficiency Testing Australia: Report No. 651, Food Proficiency Testing Program, Round 31 - Vitamins]<br /> <br /> Some upcoming proficiency testing schemes can be found in the [http://www.eptis.bam.de/en/index.htm EPTIS database].<br /> <br /> === Other methods available ===<br /> <br /> * [http://methods.aaccnet.org/summaries/86-40-01.aspx AACC 86-40.01] Vitamin B<sub>12</sub>---Microbiological Method<br /> * [http://www.aoac.org/omarev1/986_23.pdf AOAC 986.23] Cobalamin (Vitamin B12 activity) in Milk-Based Infant Formula<br /> ** turbidimetric<br /> <br /> === Literature ===<br /> <br /> * see separate child page below<br /> <br /> == EuroFIR assistance to this method/guidelines ==<br /> <br /> <br /> -----</div>

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