Fed-Batch Production of a Fermented Beverage Containing Vitamin B12

Production of fermented functional foods containing micronutrients is required for their health beneficial properties. The impact of 11 process variables on vitamin B12 production in a dairy beverage containing propionic acid was investigated. Propionibacterium freudenreichii ssp. shermanii was applied in a 3-l fermentor in the fed-batch fermentation system. The most suitable conditions for vitamin B12 production were achieved by 5% v/v inoculum size containing Propionibacterium freudenreichii (without Lactobacillus acidophilus) and continuous feeding of lactose with the rate of 0.04 l/h at 36°C in a medium containing 25 g/L molasses, 10 g/L corn steep liquor, at pH=6.5, after 96 h fermentation. Maximum vitamin concentration (30 mg/L) and productivity (7.5 mg/L.day) were obtained in trial 9. Organoleptic properties of the fermented beverage were also acceptable for panelists and no significant difference was observed between samples and control during 6 days refrigerated storage.