Optimization of lactic fermentation parameters of sugar beet (Beta vulgaris L.) puree with Lactobacillus plantarum and Lactobacillus casei

This research investigates the lactic fermentation process of sugar beet (Beta vulgaris L.) puree with the aim of creating a functional probiotic product. The focus is on optimizing fermentation conditions to enhance health benefits, thereby serving as a functional ingredient for various applications within the food industry. The lactic fermentation process utilized two strains, Lactobacillus plantarum and Lactobacillus casei, which were evaluated at different concentrations in both single (phase A) and mixed (phase B) applications. Critical parameters analyzed included fermentation duration, corn steep liquor (CSL), whey and glucose syrup, with a focus on their impacts on betaine levels, probiotic viability, antioxidant capacity, pectin content, sugar, lactic acid, and acetic acid. Through response surface methodology, optimal conditions were determined: For the A - L. casei sample, the optimal conditions included 4.78 % inoculation, 9.64 % syrup, and 1 % whey, with a fermentation period of 39.96 h. Under these conditions, the process yielded 1.833 mg/mL betaine and exhibited an antioxidant activity of 491.5 µm. The A - L. plantarum sample exhibited 5 % inoculation under similar conditions, yielding 1.863 mg/mL of betaine and an antioxidant activity of 475.71 µm. In the mixed B sample, the optimal conditions were identified as 5 % inoculation with a combination of 34.76 % L. plantarum and 25 % L. casei. Under these conditions, 1.38 mg/mL of betaine was produced after 67.76 h. These optimized samples hold significant potential as ingredients for the development of functional food products.