An overview of the functionality of exopolysaccharides produced by lactic acid bacteria

Lactic acid bacteria (LAB) that produce exopolysaccharides (EPSs) play an important role in the dairy industry because of their contribution to the consistency and rheology of fermented milk products. The EPS polymers can be considered as natural biothickeners because they are produced in situ by the LAB-starters that have General Recognised As Safe status (GRAS). The physico-chemical properties of EPSs determine their viscosifying efficiency. Hence, the knowledge of the structure-function relationship of these biopolymers is crucial in order to choose or design polymers for a specific technological application. In addition, health benefits have been attributed to some of these EPSs, particularly antitumor and immunomodulating activities. Also a prebiotic role has been suggested. However, almost all studies were performed in vitro and scarce information is available concerning in vivo experiments with oral administration. This overview focuses on the recent information about the functional properties of lactic acid bacterial EPSs, including both technological and health-promoting aspects. (C) 2002 Elsevier Science Ltd. All rights reserved.