Improvement of Fermented Cucumber Characteristics by Starter Culture of Lactobacillus plantarum, L. bulgaricus and S. thermophiles

Abstract

ABSTRACT: Fermented cucumber is a traditional lactic acid fermentation that is related to the presence of microorganisms. In this study, the use of suitable <em>L. plantarum </em>starter culture with <em>L.bulgaricus</em> and <em>S. thermophilus</em> to improve the cucumber fermentation process with high quality has been studied. Cucumbers in brine containing 4 to 6% NaCl and 0.2 to 0.4% Inulin (w/v) were inoculated with different LAB strains and analysed for microbial and physicochemical characteristics. The numbers of LAB strains were 7.46 log₁₀ cfu/ml in a solution containing 4% NaCl, 0.4% Inulin and a mixed starter culture on the sixth day. The initial salt concentration of 4% (w/v) and Inulin concentration of 0.4% was favored for the rapid growth of LAB. In the mixed starter culture, the value of titratable acidity and pH were 0.6% and 3, respectively, on the sixth day. The inoculated 6% NaCl and 0.4% Inulin solution with mixed starter culture had lower numbers of aerobic mesophilic and yeast (6.38 and 6.65 log₁₀ cfu/ml) on the sixth day. The inoculated 4% NaCl solution had lower hardness and l*, a*, b* values and the highest ranking in flavor. In order to control the fermentation of cucumbers, it is advisable to make heavy inoculation with the mentioned strainsthat produce high quality uniform and safe products.