Sauerkraut with the addition of lactobacillus casei: Effects of salt and sugar concentrations on fermentation and antioxidant activity

Background: Spontaneous fermentations have several disadvantages, and additions of lactic acid bacteria can improve sauerkraut fermentations and quality. Salt and sugar concentrations are important factors in sauerkraut fermentations, and the growth and activity of lactic acid bacteria can affect antioxidant activity of sauerkrauts. Objective: This study developed sauerkrauts with the addition of Lactobacillus casei and investigated how salt and sugar concentrations affected their fermentation and antioxidant activity. Methods: A fresh cabbage was washed and cut, before salt (1.0%; 1.5% and 2.0%) and sugar (0% and 2.0%) were added, prior to inoculation with a L. casei culture at 10% (v/w). The cabbage was then incubated at 28^oC for 5 days. The controlled lactic fermentation of the cabbage without culture and sugar, but with salt at 2.5% was performed. The sauerkrauts were evaluated for total lactic acid bacteria, pH, total acidity, phenolic content and DPPH scavenging activity. Results: The fermentation increased the total lactic acid bacteria counts in the sauerkrauts from 1.38 x 10⁹ to 3.86 x 10⁹ cfu/mL, and this demonstrated significant (p<0.05) direct salt and sugar effects. The high salt and sugar concentrations also increased the total acidity, antioxidant activity and phenolic content, but lowered the pH of the sauerkrauts. The additives (L. casei culture, salt and sugar), therefore, improved the sauerkraut fermentation and antioxidant activity compared to the control. Conclusion: With added sugar and salt, L. casei improved the sauerkraut fermentation and antioxidant activity, and both sugar and salt can each be added at a low (2%) concentration for maximum effects.