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Vitamin B12, folate and folate-binding proteins in dairy products

analysis, process retention and bioavailability

Arkbåge, Karin (2003). Vitamin B12, folate and folate-binding proteins in dairy products. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae. Agraria, 1401-6249 ; 430
ISBN 91-576-6470-6
[Doctoral thesis]

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Vitamin B12 and folate are two important B vitamins for maintaining good health, being involved in amino acid metabolism and DNA synthesis. Milk and dairy products are good sources of vitamin B12 and folate. Moreover, they are of interest due to their content of folate-binding proteins (FBP), since it was hypothesised that these promote folate bioavailability. Furthermore, fermentation of milk is a way to increase the content of both vitamins. Vitamin analysis in fermented dairy products is complicated due to the complex matrix. To gain reliable data on vitamin content, retention and bioavailability, emphasis throughout the project was put on optimisation and evaluation of methods for quantification. A commercial radio protein-binding assay (RPBA), produced for clinical samples, was evaluated regarding, e.g. assay pH, buffer molarity and food matrix effects. The optimised RPBA was demonstrated to be suitable for quantification of vitamin B12 in milk and fermented dairy products, and of folate quantification in dairy samples containing mainly 5-methyl-tetrahydrofolate. One aim of this project was to map the retention of vitamin B12 and folate during manufacture of six fermented dairy products. Results showed, e.g. that fermentation of milk followed by storage at 4 °C for 14 days decreased vitamin B12 concentrations in fermented milk by 40-60% compared with concentration in the milk. However, vitamin B12 was 4-7-fold concentrated during hard cheese making. Regarding folate, the concentrations of folate increased both during fermentation of milk to yoghurt and during manufacture of cheese. Another aim was to study folate bioavailability from milk and fermented milks using both an in vitro gastrointestinal and a human model. Focus was on studying the stability and the nutritional role of bovine milk FBP, which are suggested to have a positive impact on folate bioavailability. Both studies showed FBP to partly endure in vitro and in vivo gastrointestinal passage, and further, to decrease in vitro and in vivo folate bioavailability.

Authors/Creators:Arkbåge, Karin
Title:Vitamin B12, folate and folate-binding proteins in dairy products
Subtitle:analysis, process retention and bioavailability
Series Name/Journal:Acta Universitatis Agriculturae Sueciae. Agraria
Year of publishing :November 2003
Number of Pages:69
ALLI. Arkbåge, K., Witthöft, C., Fondén, R., and Jägerstad, M. (2003) Retention of vitamin B12 during manufacture of six fermented dairy products using a validated radio protein-binding assay. International Dairy Journal 13: 101-109 II. Strålsjö, L., Arkbåge, K., Witthöft, C., and Jägerstad, M. (2002) Evaluation of a radioprotein-binding assay (RPBA) for folate analysis in berries and milk. Food chemistry 79(4): 525-534 III. Arkbåge, K., Verwei, M., Havenaar, R., and Witthöft, C. (2003) Bioaccessibility of folic acid and (6S)-5-methyltetrahydrofolate decreases after the addition of folate-binding protein to yogurt as studied in a dynamic in vitro gastrointestinal model. Journal of Nutrition 133: 3678-3683 IV. Verwei, M., Arkbåge, K., Mocking, H., Havenaar, R., and Groten, J. The FBP binding characteristics during gastric passage are different for folic acid and 5-CH3-H4folate as studied in a dynamic in vitro gastrointestinal model. Accepted for publication in Journal of Nutrition V. Witthöft, C., Arkbåge, K., Lennernäs, H., Lundin, E., and Hallmans, G. Folate bioavailability from different fortified dairy products using a human ileostomy model. Manuscript
Place of Publication:Uppsala
ISBN for printed version:91-576-6470-6
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:Q Food science > Q02 Food processing and preservation
Subjects:Not in use, please see Agris categories
Agrovoc terms:fermentation, milk products, quantitative analysis, analytical methods, vitamin B12, folic acid, bioavailability
Keywords:fermented dairy products, quantification, vitamin retention, vitamin B12, folic acid, 5-methyltetrahydrofolate, folate bioavailability
Permanent URL:
ID Code:407
Department:(NL, NJ) > Dept. of Food Science (until 161231)
Deposited By: Karin Arkbåge
Deposited On:24 Nov 2003 00:00
Metadata Last Modified:02 Dec 2014 10:04

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