Fed-Batch Production of a Fermented Beverage Containing Vitamin B12

Abstract

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.

Keywords

• co-culture
• fed-batch fermentation
• plackett-burman
• process variables
• propionibacterium freudenreichii
• propionic acid
• vitamin b12