Symbiotic fermentation study of Acetobacter orientalis and lactic acid bacteria for lactobionic acid enriched yoghurt production

Abstract

Symbiotic fermentation of lactic acid bacteria and Acetobacter orientalis intended to produce lactobionic acid-enriched yoghurt was studied. Commercial lactic acid bacteria (1%) and A. orientalis (10, 15, 20%) were inoculated in milk and incubated at 30°C for 16 h. Incubation parameters, including acidity, lactose conversion, and bacterial colony count, were analysed every 6th hour. Secondary fermentation parameters like acidification rate, bacterial growth rate, generation time and conversion rate of lactose to lactic acid and lactobionic acid were also estimated. The incubation time and A. orientalis level had significant (P < 0.05) effects on the incubation parameters of the lactobionic acid-enriched yoghurt during the incubation period. This study suggests 20% A. orientalis, 1% lactic bacteria inoculation and 30°C/16 h incubation for yoghurt with higher lactobionic acid content.