Pantothenic acid

   
Figure 1. Pantothenic acid, C9H17NO5, Mw = 219,23 g/mol

The only vitamin active form of pantothenic acid is dextro- form. In foods, pantothenic acid is most often in a form of salt or bound to proteins.

Synonyms for pantothenic acid:

• vitamin B5, pantothenate, chick antidermatitis factor

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Golden standard

• No EN Standard available.

• AOAC 945.74 Pantothenic Acid in Vitamin Preparations
  • Microbiological assay described in AOAC 960.46.

Method indicator

• Name
• Code

Scope

The method AOAC 945.74 describes a microbiological method for the determination of pantothenic acid.

Principle

After extraction, pantothenic acid content of the sample is determined by microbiological assay using turbidimetric method.

Key steps

Preparing of the sample test solution

• The pH of the solution should be maintained below 7,0.
• Water is added and pH of the sample solution is adjusted to 5,65 with CH₃COOH or CH₃COONa.
• Solution is autoclaved (5-7 min, 121-123 °C).
• Sample treatments are continued according to AOAC 944.13.

Microbiological assay

• Microbiological assay is carried out according to AOAC 960.46 using calcium pantothenate standard solution, basal medium stock solution with ingredients that are suitable for determination of pantothenic acid, and inoculum with Lactobacillus plantarum ATCC 8014.

Preparation of test tubes

• Microbiological assay is performed using test tubes.
• All of the blanks, standard solutions and samples are prepared at least in duplicates.
• Both an uninoculated and inoculated blank are prepared.
• Test tubes having four different dilution levels of sample solutions are prepared.
• Water and basal medium stock solution are added to test tubes.
  • The total volume of the solution in every test tube is 10 ml.
• Test tubes are sterilised prior to inoculation of test tubes.
  • Only unincoulated blanks are not inoculated.

Determination by turbidimetric method

• Tubes are incubated at 30-40 °C for 16-24 h.
• Photometer is calibrated with standard stock solutions.
  • Calibration curve is formed by plotting the transmittance (%) for every dilution level against the corresponding content (mg dry weight).
• The test tube solutions are transferred to optical cells and transmittance is measured photometrically.
• Spectrometer is set to 540-660 nm and adjusted to 100 % transmission for uninoculated blanks.
• After achieving a steady state, absorbance of test tubes are read.

Calculation

• The results obtained are potency of product expressed as D-pantothenic acid.
  • The value must be multiplied by 1,087 to express the results as calcium pantothenate and by 1,100 to express the results as sodium pantothenate. 
• Pantothenic acid content/ml is calculated. 
• Average of values are calculated taking into account such samples that do not vary by more than 10 % from the average.

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Remarks

• The method can be used only for determination of calcium pantothenate or other free forms of pantothenic acid.
• pH of the sample solution should not exceed the value 7,0.

Criteria for analytical performance and analytical quality control

• Greenfield and Southgate discuss the criteria for analytical performance and quality of analytical data in their book.
  • Greenfield H, Southgate DAT. 2003. Food composition data - production, management and use. Elsevier Applied Science, London, UK.

Certified Reference Materials/Standard Reference Material

• link to detailed data

Proficiency testing schemes 

 Here are listed some completed, on-going and/or upcoming proficiency testing schemes concerning pantothenic acid:

DLA - Dienstleistung Lebensmittel Analytik GbR: 33/2012 Food Supplement II: Biotin, Vitamin C, Niacin and Pantothenic Acid

PTA - Proficiency Testing Australia: Report No. 651 Foor Proficiency Testing Program (Round 31) - Vitamins

 Some upcoming proficiency testing schemes can be found in the EPTIS database.

Other methods available

• AOAC 945.73 Calcium Pantothenate in Vitamin Preparations
  • spectrophotometric
• AOAC 992.07 Pantothenic Acid in Milk-Base Infant Formula
  • microbiological, turbidimetric

 Literature

•  see separate child page below

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