Change of the Form of Vitamin. B₁₂ Compounds during the Fermentation of Milk by Lactobacillus helveticus B-1

Abstract

The existing mode of vitamin B₁₂ in fermented milk was examined by preparing vitamin B₁₂enriched fermented milk by Lactobacillus helveticus B-1. The recovery of vitamin B₁₂ by the ordinary extraction method with potassium cyanide was less than 80% of B₁₂ in the fermented milk. Nearly 30% of the added B₁₂ (cyanocobalamin) was present in a precipitate of the fermented milk containing the cells of L. helveticus B-1. The form of vitamin B₁₂ was partly changed during the fermentation process into adenosyl-B₁₂, which was characterized by paper electrophoresis at different pH values, by the spectrophotometric method and by micro-HPLC combined with the microbiological determination method using Escherichia coli 215.