Exopolysaccharide-producing lactic acid bacteria in the manufacture of soft cheese

Soft cheese was manufactured with exopolysaccharide (EPS)-producing strains of Lactococcus lactis subsp. cremoris (Lac. cremoris) and Lactobacillus sakei (Lb. sakei). EPS-producing strains were fermented in a growth promoting medium and added to the cheese milk in concentrations of 5 and 10 %. The effects of EPS and EPS-producing strains on cheese production and composition were investigated and compared to standard cheeses inoculated only with Streptococcus thermophilus (S. thermophilus). Compared to the standard, whey removal during cheese processing was delayed, Due to a high moisture content of EPS-containing cheese and low pH values, ripened cheeses showed a soft, bitter outer layer, a chalky, acidic core and dead mould. The process was improved by an appropriate acidification and whey removal during cheese manufacture. Ad hoc, acidification and whey removal were studied individually in model experiments in order to demonstrate their time and temperature dependency. Additionally, the influence of thermisation of the fermented medium on acidification and syneresis was studied. The results for acidification and syneresis were combined and target values for curd grain treatment were determined. By adjusting the manufacturing parameters, production of well tasting soft cheeses with strains of Lac. cremoris and Lb. sakei using 10 % fermented, thermised medium was possible.