Effect of Bacteria Exopolysaccharide on Milk Gel Formation

Abstract

The main objective of this study was to determine effect of exopolysaccharide (EPS) from bacteria on formation of milk gel. Milk gel was made from 10%, 15% and 20% Reconstituted Skim Milk (RSM). EPS at different concentrations (0%, 0.2%, 0.4%, 0.6%, 0.8% and 1.0% according to our previous study) were added to RSM, heated at 60˚C for 30 minute and 85˚C for 30 second and cooled to 5˚C before vis-cosity and pH were examined using viscometer and pH-meter. Viscosity was dependent on the concentra-tions of skim milk, increasing as the concentration of RSM increased. Lower concentration of EPS, vis-cosity showed a slight increase, but at 0.4% EPS, viscosity of milk gel increased rapidly and continued to increase up to 1%. Microstructure was determined using scanning electron microscope to evaluated milk gel formation. Interaction between milk protein and EPS was showed as network aggregate one and another. EPS function as binding agent between one molecule of casein and another. These results indi-cated that EPS could be used to increase quality of milk gel.