PROTECTANT EFFECT OF SUGARS ON PRESERVATION OF LACTIC ACID BACTERIA

BRIZUELA N.S.; BRAVO-FERRADA, BÁRBARA M.; GERBINO, E.; A. GOMEZ ZAVAGLIA; SEMORILE L; TYMCZYSZYN E. E.

Simposio; V Simposio Internacional de Bacterias Lácticas (SIBAL); 2016

CERELA

Freeze-drying and spray-drying are widely extended methods to preserve lactic acid bacteria, enabling a long term storage of starters for the food and beverages industry. However, during dehydration, the loss of water produces damages on cell macromolecules that lead to a loss of viability. To protect microorganisms against these damages, sugars and other oligosaccharides can be added either in the culture or in the dehydration medium. Sugars are able to form hydrogen bonds with polar groups of proteins and lipid membranes, and protect their structures and functions by replacing water molecules. In addition, sugars can form glassy states characterized by their high viscosity, which avoid deteriorative reactions. The successful preservation of lactic acid bacteria depends, in a great extent, on the physicochemical properties of protectants and on the thermophysical properties of the dried matrices. The knowledge of these sugar properties is useful to optimize the survival of dried starters and enhance their shelf-life.