The combined effect of Bacillus coagulans, potassium chloride, and yeast extract on the physicochemical and sensory characteristics of a functional vegetable sausage

In this study, we investigated the combined effect of Bacillus coagulans and a mixture of potassium chloride and yeast extract on the microbial, physicochemical, and sensory properties of a vegetable sausage (probiotic and with reduced salt content) during four weeks of refrigerated storage. The viable count of B. coagulans in probiotic vegetable sausage containing potassium chloride solution and 1% or 2% yeast extract was 8.34 log CFU/g for both groups on the first day and decreased to 7.2 and 7.42 log CFU/g, respectively, after four weeks of storage. Adding the mixture of potassium chloride and 1% yeast extract to probiotic sausage improved the survival of B. coagulans by about 0.2 log CFU/g compared to probiotic sausage without the mixture. Similarly, 2% yeast extract instead of 1% improved the probiotic bacteria viability count by about 0.22 log CFU/g. Moreover, adding probiotic bacteria and the mixture of potassium chloride and yeast extract to the vegetable sausage altered the pH of the product during the storage period. On day 28, the pH values for probiotic samples without potassium chloride and yeast extract, probiotic samples with a mixture of 1% potassium chloride and 1% yeast extract, and probiotic samples with a mixture of 1% potassium chloride and 2% yeast extract were 5.75, 5.73, and 5.7, respectively. Potassium chloride and yeast extract improved the taste score and overall product acceptance while deteriorating color characteristics. In general, the results showed that replacing salt with potassium chloride reduced the product's sodium content. At the same time, yeast extract improved the survival of the probiotic bacterium B. coagulans, lowered pH during refrigerated storage time, and enhanced sensory properties related to taste, color, and overall acceptance of vegetable sausages.