Effect of Salt Concentration and pH value on the Lactic Fermentation Process of Kohlrabi (Brassica oleracea L.)

Vegetables have been shown to be able to provide nutrients, including vitamins, minerals and especially fiber, and release toxins that arise during the digestion of food. As a result, the importance of vegetables has been increasingly emphasized in the human diet. In this study, Kohlrabi, a vitamin C-rich vegetable, was used for lactic fermentation. The whole process was optimized by varying a wide range of parameters including concentrations of salt solution and pH value on the growth of lactic acid bacteria, product texture and sensory characteristics. Current results revealed the optimal conditions for the fermentation process are as follows: NaCl solution used of 3.5%, initial pH 4.2, and MnCl2 with a concentration of 30 mM. The obtained Kohlrabi pickle products exhibited acceptable quality and good sensory scores after 2 days. Elevated temperature was also found to be associated with loss of hardness, quality loss and longer fermentation time. Optimized Kohlrabi pickling process will contribute to diversifying pickled vegetable products to avoid the defects caused by improper processing.