A rapid high-performance liquid chromatography (HPLC) method for the extraction and quantification of folates in dairy products and cultures of Propionibacterium freudenreichii
Date
2012
Authors
van Wyk J.
Britz T.J.
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Abstract
Nutritional folate deficiencies in Southern African communities necessitated mandatory fortification. Current microbiological assays (MA) used to measure food folates, essential for quality control and regulatory purposes, are time-consuming. This study describes an alternative extraction and detection method for folates in dairy products and Propionibacterium freudenreichii cultures. Folates were extracted by heating with a phosphate buffer (pH 6.0). Polyglutamates were deconjugated with chicken pancreas and hog kidney deconjugases. Samples were purified using strong anion exchange solid phase extraction. Reversed-phase high-performance liquid chromatography (HPLC) using an acetonitrile-phosphate buffer (pH 2.2) gradient effectively separated four vitamers. Fluorescence (tetrahydrofolate (THF), 5-CH
3-THF and 5-CHO-THF), and UV detection (folic acid) were used, calibration curves were linear (R
2>0.0997), and detection and quantification limits were 0.0006 to 0.015 and 0.002 to 0.05 μg/ml, respectively. Accuracy was 80 to 108% and intra- and inter-day precision [%relative standard deviation (%RSD)] were lower than 4%. The method, validated against the standard MA, is a selective, sensitive, reliable and rapid alternative. © 2012 Academic Journals.
Description
Keywords
Folate, High-performance liquid chromatography (HPLC), Microbiological folate assay, Propionibacterium freudenreichii
Citation
African Journal of Biotechnology
11
8
2087
2098
11
8
2087
2098