Proceedings of The 3rd International Academic Conference on Research in Engineering and Technology
Year: 2024
DOI:
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Alteration of Folates Concentration Produced by Selected S. Thermophilus Strains When Cultivated with and without L. Bulgaricus
PiotrWójcik
ABSTRACT:
After the initial screening of 54 monocultured S. thermophilus strains from the LB Bulgaricum® collection, only two produced natural folates over 200 µg/l. Considering the fact that in Bulgarian yogurt S. thermophilus is symbiotically growing with L. bulgaricus, we have analyzed 4 co-fermented combinations with one of our L. bulgaricus strains – frequently used in our yogurt starter cultures. Previously optimized method to decompose the polygutamate tailes of the folates by initial treatment of the samples with rat serum in the presence of antioxidants: ascorbic acid and DTT was used. The mesuremnt of the different folate forms concentration was performed by UHPLC MS/MS Fourier transformation mass specctrometry. Results of all 4 combinations demonstrate significant increase of 5-Methylene tetrahydrofolate (5-MeTHF) and 5-10-Methenyl tetrahydrofolate and decrease of 5-Methyl tetrahydrofolate (5-MTHF) concentration when co-fermented compared to the monoculture. This circumstance can be attributed to the consumption of 5-MTHF by the L.bulgaricus strain, and the additional production of 5-MeTHF and 5-10-Methenyl tetrahydrofolate by L.bulgaricus. We have observed on one hand the influence of the co-fermentation and on the other the conditions of the fermentation (temperature, duration and percentage of inoculum) over the concentration of the produced folates in total and in the different folate forms. It was demonstrated that concentration of total folates is higher when cultivated on 43°C instead of 37°C and the concentration is increasing until 6h of fermentation and then decreasing due to likely consumption by the L.bulgaricus strain.
keywords: Fermentation, Mass-spectrometry, Probiotics, Vitamins, Yogurt