Optimization of carrot fermentation conditions in rice bran bed using Lactobacillus plantarum.

Background: A statistical model was developed in this study to describe lactic acid production through a fermentation process of carrot in a rice bran bed by Lactobacillus plantarum.

Methods: Response surface methodology (RSM) based on Box-Behnken design was employed to statistically evaluate and optimize the conditions for maximum lactic acid production.

Results: The significance and interaction of salt concentration, water and initial L. plantarum starter density on final lactic acid content were found. With the use of the developed quadratic model equation, a maximum achieved lactic acid content of 1.35% was obtained in a rice bran bed fermentation process at optimum operating conditions of approximately 2.95% salt, 48.24% water and 2.9 log cfu/g of L. plantarum. After fermentation, the amount of total polyphenol content, antioxidant activity and carbohydrate had increased while the β-carotene in carrot was significantly retained (92.84%).

Conclusions: The above results could provide a practical basis for the fermentation process in rice bran bed to produce a delicious and reliable product using L. plantarum strain XK 1.4 which could be a significant contribution to the food industry.