Difference between revisions of "Summary - folates"

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<br class="atl-forced-newline" /></p>
 
<br class="atl-forced-newline" /></p>
  
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<table style="border: 1px solid black;border-collapse: collapse;">
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        <tr style="border: 1px solid black;border-collapse: collapse;" class="tablesorter-headerRow">
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            <th style="border: 1px solid black;border-collapse: collapse;">
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                    <p> Matrix parameter </p>
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            </th>
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            <th style="border: 1px solid black;border-collapse: collapse;">
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                    <p>
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                        <strong>CRM 121</strong>
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                        <br class="atl-forced-newline">
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                        <strong>Wholemeal flour</strong>
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                    </p>
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            </th>
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            <th style="border: 1px solid black;border-collapse: collapse;">
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                    <p>
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                        <strong>CRM 421</strong>
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                        <br class="atl-forced-newline">
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                        <strong>Milk powder</strong>
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                    </p>
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            </th>
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            <th style="border: 1px solid black;border-collapse: collapse;">
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                    <p>
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                        <strong>CRM 485</strong>
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                        <br class="atl-forced-newline">
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                        <strong>Mixed vegetables</strong>
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                    </p>
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            </th>
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            <th style="border: 1px solid black;border-collapse: collapse;">
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                    <p>
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                        <strong>CRM 487</strong>
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                        <br class="atl-forced-newline">
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                        <strong>Pig liver</strong>
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                    </p>
 +
               
 +
            </th>
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        </tr>
  
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<tr>
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        <tr style="border: 1px solid black;border-collapse: collapse;">
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<th>
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                <p> Repeatability RSDr </p>
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<p> Matrix parameter </p></th>
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            </td>
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<th>
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                <p> 9,2 % </p>
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<p> <strong>CRM 121</strong> <br class="atl-forced-newline" />
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            </td>
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<strong>Wholemeal flour</strong> </p></th>
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            <td style="border: 1px solid black;border-collapse: collapse;">
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                <p> 6,7 % </p>
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<th>
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            </td>
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<p> <strong>CRM 421</strong> <br class="atl-forced-newline" />
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<strong>Milk powder</strong> </p></th>
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                <p> 4,9 % </p>
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            </td>
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<th>
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<p> <strong>CRM 485</strong> <br class="atl-forced-newline" />
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                <p> 14,8 % </p>
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<strong>Mixed vegetables</strong> </p></th>
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            </td>
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        </tr>
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<th>
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        <tr style="border: 1px solid black;border-collapse: collapse;">
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<p> <strong>CRM 487</strong> <br class="atl-forced-newline" />
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<strong>Pig liver</strong> </p></th>
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                <p> Reproducibility RSDR </p>
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</tr>
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            </td>
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<tr>
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                <p> 22,3 % </p>
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            </td>
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<td>
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<p> Repeatability RSDr </p></td>
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                <p> 16,9 % </p>
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            </td>
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<td>
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<p> 9,2 % </p></td>
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                <p> 13,8 % </p>
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            </td>
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<td>
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            <td style="border: 1px solid black;border-collapse: collapse;">
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<p> 6,7 % </p></td>
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                <p> 17,0 % </p>
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            </td>
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<td>
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        </tr>
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<p> 4,9 % </p></td>
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</table>
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<td>
 
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<p> 14,8 % </p></td>
 
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</tr>
 
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<tr>
 
−
 
 
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<td>
 
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<p> Reproducibility RSDR </p></td>
 
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−
<td>
 
−
<p> 22,3 % </p></td>
 
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<td>
 
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<p> 16,9 % </p></td>
 
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<td>
 
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<p> 13,8 % </p></td>
 
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<td>
 
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<p> 17,0 % </p></td>
 
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</tr></table>
 
  
  

Revision as of 08:07, 23 November 2017

EN 15652:2009 Foodstuffs - Determination of niacin by HPLC:


Scope


This European Standard specifies a microbiological method for the determination of the total folate content of foodstuffs by turbidimetric detection of the growth of the microorganism Lactobacillus casei, subsp. rhamnosus (ATCC 7469).


The method allows for the determination of folates in foodstuffs, including naturally occurring folates and added folic acid (pteroylglutamin acid).


Principle


Samples suspended in phosphate buffer are heated to enable extraction of folates. Protease and α-amylase treatment may be used to further digest the food matrix. Naturally occurring folylpolyglutamates are hydrolysed with γ-glutamyl hydrolase (EC 3.4.19.9) to folylmono- or folyldi-glutamates.


Extracted folates are diluted with basal medium containing all required growth nutrients except folate. The growth response of Lactobacillus casei, subsp. rhamnosus (ATCC 7469) to extracted folates is followed turbidimetrically and is compared to the growth response to calibrant solutions with known concentration.


The method allows for the optional use of a semi-automated liquid-handling system and of a microplate or test tubes for incubation of the microorganism.


Precision data

Matrix parameter

CRM 121
Wholemeal flour

CRM 421
Milk powder

CRM 485
Mixed vegetables

CRM 487
Pig liver

Repeatability RSDr

9,2 %

6,7 %

4,9 %

14,8 %

Reproducibility RSDR

22,3 %

16,9 %

13,8 %

17,0 %





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