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Development and validation of chromatographic methods to study folate derivatives produced by yeasts

Patring, Johan (2007). Development and validation of chromatographic methods to study folate derivatives produced by yeasts. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2007:31
ISBN 91-576-7330-5
[Doctoral thesis]

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Folate, or folic acid, is an important water soluble B vitamin that exists in many different forms. Its presence is necessary for synthesis of DNA and RNA and methylation of homocysteine to methionine. Deficiency of folate is closely connected to increased risk of neural tube defects, a serious birth defect, and development of anaemia. Humans cannot synthesise folate by themselves and therefore depend on an adequate supply through food intake. However, the recommended daily intake of folate is not reached by many people, especially women in fertile ages. This thesis aimed to investigate possibilities for enhancing folate production from yeast for use as biofortificants in food to increase the natural folate content. To quantify folate, analytical methods were developed and validated. This involved optimisation of sample pre-treatment steps, HPLC methods and LC-MS methods. The main findings were that folate analysis of yeast could be facilitated by excluding an SPE step prior to HPLC analysis, that sample handling and choice of antioxidant greatly influenced folate stability, that choice of reversed-phase column considerably affected folate separation/retention and that LC-MS provided a powerful tool for yeast folate analysis. These developed analytical methods were used to investigate differences between yeast strains to produce folates. Furthermore, effect of cultivation conditions on folate content in yeast was studied. The main conclusions from these experiments were that careful selection of yeast strain may considerably increase folate content in food. It was also shown that folate concentration in yeast was significantly increased by optimising the cultivation procedure. The folate derivatives that were found to exist in yeast were tetrahydrofolate, 5-methyltetrahydrofolate, 10-formylfolic acid and 5-formyltetrahydrofolate. The findings in this thesis show that there are great possibilities for increasing folate content in yeast-fermented foods, e.g. bread and dairy products, if a proper yeast strain is used under optimal growth conditions in appropriate culturing media.

Authors/Creators:Patring, Johan
Title:Development and validation of chromatographic methods to study folate derivatives produced by yeasts
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2007
Number of Pages:65
ALLI. Patring, J.D.M., Jastrebova, J.A., Hjortmo, S.B., Andlid, T.A. & Jagerstad, I.M. 2005. Development of a simplified method for the determination of folates in baker's yeast by HPLC with ultraviolet and fluorescence detection. Journal of Agricultural and Food Chemistry 53, 2406-2411. II. Patring, J.D.M., Johansson, M., Yazynina, E. & Jastrebova, J. 2005. Evaluation of impact of different antioxidants on stability of dietary folates during food sample preparation and storage of extracts prior to analysis. Analytica Chimica Acta 553, 36-42. III. Patring, J.D.M., Lanina, S.A. & Jastrebova, J.A. 2006. Applicability of alkyl-bonded ultra-pure silica stationary phases for gradient reversed-phase HPLC of folates with conventional and volatile buffers under highly aqueous conditions. Journal of Separation Science 29, 889-904. IV. Patring, J.D.M. & Jastrebova, J.A. 2007. Application of liquid chromatography-electrospray ionisation mass spectrometry for determination of dietary folates: Effects of buffer nature and mobile phase composition on sensitivity and selectivity. Journal of Chromatography A 1143, 72-82. V. Hjortmo, S., Patring, J., Jastrebova, J. & Andlid, T. 2005. Inherent biodiversity of folate content and composition in yeasts. Trends in Food Science & Technology 16, 311-316. VI. Patring, J.D.M., Hjortmo, S.B., Jastrebova, J.A., Svensson, U.K., Andlid, T.A. & Jagerstad, I.M. 2006. Characterization and quantification of folates produced by yeast strains isolated from kefir granules. European Food Research and Technology 223, 633-637. VII. Hjortmo, S., Patring, J., & Andlid, T., Effect of cultivation conditions on folate content in S. cerevisiae. Basic manuscript to be complemented with further data.
Place of Publication:Uppsala
ISBN for printed version:91-576-7330-5
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:folic acid, yeasts, chromatography, hplc, sampling, foods, food enrichment
Keywords:folates, analysis, HPLC, LC-MS, method development, sample pre-treatment, yeast, food, cultivation conditions, biofortification
Permanent URL:
ID Code:1409
Department:(NL, NJ) > Dept. of Food Science (until 161231)
Deposited By: Johan Patring
Deposited On:24 Apr 2007 00:00
Metadata Last Modified:02 Dec 2014 10:11

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