Effect of Mixed Inoculums Volume and pH on Anti Nutritional Level in Cabbage Fermentation using Saccharomyces cerevisiae and Lactobacillus plantarum

Abstract

Abstract Cabbage (Brassica oleracea var. capitata) that is one of the widely consumed vegetables, contains significant amounts of anti-nutritional components, such as tannin. This component can be reduced by fermentation, where bacterial tannase activity is able to degrade tannin into glucose and gallic acid. A simultaneously mixed cultures fermentation using Saccharomyces cerevisiae and Lactobacillus plantarum has been developed because they possess some mutualism interaction that can be beneficial in the fermentation process. Therefore, this research was focused on the effect of mixed inoculums volume of S. cerevisiae and L. plantarum and initial culture pH on the tannin and glucose level during cabbage fermentation. The sliced cabbage was inoculated with simultaneously mixed cultures (volume ratio of yeast and bacteria used was 1:1) at a different volume range 5%-25% (v/v) and also various pH range from 4 to 7, and then incubated at room temperature in anaerobic condition for 4 days. Tannin and glucose level in fermented cabbage (both biomass and filtrate) were determined using Folin-Denis and phenol-sulphuric method, respectively. The using of 5% mixed inoculums volume and initial pH around 7 were found to be the optimum condition for tannin degradation in cabbage. The remained tannin level in these fermented cabbage decreased up to 18.58% (54.061 mg/100 g FW). This experiment reveals that the amounts of inoculums and initial culture pH affected tannin degradation during cabbage fermentation using mixed cultures of yeast and lactic acid bacteria.