Quality enhancement of fermented vegetable juice by probiotic through fermented yam juice using Saccharomyces cerevisiae
Abstract As the demand for probiotic foods continues to increase and lactose intolerance is common, it is necessary to develop a range of non-milk probiotic beverages. The purpose of this study was to evaluate the preparation process of fermented probiotic beverages using various vegetables as raw materials, and to evaluate the chemical and organoleptic properties of the mixed fermented vegetable juices. The mixed fermented vegetable juice was a beverage obtained by mixing the vegetable juice (purple cabbage, tomato and carrot) fermented by Lactobacillus plantarum and the yam juice fermented by the yeast in an appropriate ratio. During lactobacillus fermentation (48 hours at 30 °C), the cell count of Lactobacillus plantarum increased from 7.49 ± 0.21 log CFU/mL to 9.13 ± 0.19 log CFU/mL (p < 0.05), the glucose decreased from 8.924 g/L to 5.528 g/L, and the pH decreased from 5.03 to 3.62. Oxidation activity slightly decreased. The lactic acid and titratable acid/total acid content increased, and the trend of change was similar. During the yeast fermentation (28 °C, 24h), the glucose was almost depleted and ethanol was accumulated. GC-MS analysis showed that microbial fermentation had a significant effect on volatile components. The sensory evaluation results showed that the proper mixing of fermented vegetable juice and fermented yam juice had a significant increase in taste, odor and overall acceptance of the product. The mixed fermented vegetable juice has the potential to adapt to the consumer groups and has in-depth research value.