Influence of bacteria on menaquinone concentrations in fermented dairy products
department or school: Land and Food Systems, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Hartling, Ivan Grant
issued: 2017-08-16T16:42:07Z
issued: 2017
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Menaquinones (MK’s) are a form of vitamin K, supplementation with which has been shown to provide health benefits by reducing arterial calcification and improving bone density. Fortifying MK’s in foods may provide the health benefits associated with MK’s to the general population. This study aimed to increase the amount of MK’s in yogurt, which typically contains very little MK’s, by co-fermenting milk with both typical yogurt bacteria and bacteria known to produce MK’s in cheese and natto. A LC-MS/MS method was first developed to measure MK’s as well as all other fat-soluble vitamins. The LC-MS/MS method was able to quantify phylloquinone, MK-4, MK-7, MK-9, cholecalciferol, α-tocopherol, and was able to detect MK-8, but was unable to quantify ergocalciferol or retinol due to ionization suppression from the sample matrix. The LC-MS/MS method was used to measure MK’s in non-fat milk samples fermented with either one bacteria ssp. or a combination of S. thermophilus, L. bulgaricus, and one of L. lactis, L. cremoris, P. shermanii, or B. subtilis. Fermentations were carried out at 30 – 45 °C for 36 h to determine the optimal incubation temperature at which to carry out replicate fermentations. The pH was measured throughout fermentation as an indicator of overall growth and the relative amount of each bacteria ssp. after fermentation was measured using qPCR. Only L. cremoris produced MK-8 and MK-9, while all samples, including negative controls, contained high concentrations of MK-7. The qPCR results showed co-fermentations contained over 99 % S. thermophilus, except in co-fermentations with L. lactis which contained 59 % L. lactis, 41 % S. thermophilus, and < 0.1 % L. bulgaricus. Delaying inoculation of S. thermophilus and L. bulgaricus resulted in almost exclusive growth of the first inoculant. Overall, L. cremoris showed the greatest potential for enhancing the MK content of yogurt as it produced up to 234.4 ng/g MK-9, 174.9 ng/g MK-7, and produced MK-8, but further …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/62654
note: Influence of bacteria on menaquinone concentrations in fermented dairy products by Ivan Grant Hartling B.Sc. (Hons), Thompson Rivers University, 2014 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in The Faculty of Graduate and Postdoctoral Studies (Applied Animal Biology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2017 © Ivan Grant Hartling, 2017 ii Abstract Menaquinones (MK’s) are a form of vitamin K, supplementation with which has been shown to provide health benefits by reducing arterial calcification and improving bone density. Fortifying MK’s in foods may provide the health benefits associated with MK’s to the general population. This study aimed to increase the amount of MK’s in yogurt, which typically contains very little MK’s, by co-fermenting milk with both typical yogurt bacteria and bacteria known to produce MK’s in cheese and natto. A LC-MS/MS method was first developed to measure MK’s as well as all other fat-soluble vitamins. The LC-MS/MS method was able to quantify phylloquinone, MK-4, MK-7, MK-9, cholecalciferol, α-tocopherol, and was able to detect MK-8, but was unable to quantify ergocalciferol or retinol due to ionization suppression from the sample matrix. The LC-MS/MS method was used to measure MK’s in non-fat milk samples fermented with either one bacteria ssp. or a combination of S. thermophilus, L. bulgaricus, and one of L. lactis, L. cremoris, P. shermanii, or B. subtilis. Fermentations were carried out at 30 – 45 °C for 36 h to determine the optimal incubation temperature at which to carry out replicate fermentations. The pH was measured throughout fermentation as an indicator of overall growth and the relative amount of each bacteria ssp. after fermentation was measured using qPCR. Only L. cremoris produced MK-8 and MK-9, while all samples, including negative controls, contained high concentrations of MK-7. The qPCR results showed co-fermentations contained over 99 % S. thermoph…
has type: Thesis/Dissertation
date issued: 2017-09
is shown at: 10.14288/1.0354408
language: eng
degree discipline: Applied Animal Biology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/62654