Application of osmometry in monitoring fermentation of milk.

Abstract

Fermentation of milk yields many other products apart from lactic acid. This study was carried out to monitor the progress of fermentation by measuring the total solute concentration i.e. osmolality in fermenting milk. Five samples each of raw milk, pasteurised milk and UHT (ultra-high temperature treated) milk were incubated aerobically without starter culture at 37°C for 3 days. Osmolality was measured by freezing point depression at the beginning of incubation and at exactly the same time for the next 3 days. Osmolality of raw milk (mean±SD) increased from 290.2±8.0 to 405.6±31.06 mOsmoles kg in one day and stabilized around this 1