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.

摘要
随着益生菌食品需求持续增长，且乳糖不耐受现象较为普遍，开发多款非乳基益生菌饮品已成必要之举。本研究旨在评估以多种蔬菜为原料制备发酵型益生菌饮品的工艺，并对混合发酵蔬菜汁的化学特性与感官品质进行评价。本研究制备的混合发酵蔬菜汁饮品，是将植物乳杆菌（Lactobacillus plantarum）发酵所得的蔬菜汁（紫甘蓝、番茄与胡萝卜汁）与酵母发酵的山药汁按适宜比例混合制得。在乳酸菌发酵阶段（30℃下发酵48h），植物乳杆菌的活菌数从7.49±0.21 log CFU/mL提升至9.13±0.19 log CFU/mL（p<0.05），葡萄糖含量从8.924 g/L降至5.528 g/L，pH值从5.03下降至3.62，氧化活性略有降低；乳酸含量与可滴定酸/总酸占比均有所上升，二者变化趋势相近。在酵母发酵阶段（28℃下发酵24h）中，葡萄糖几乎被耗尽，同时乙醇得以积累。气相色谱-质谱联用（GC-MS）分析结果表明，微生物发酵对饮品的挥发性成分具有显著影响。感官评价结果显示，将发酵蔬菜汁与发酵山药汁按适宜比例混合后，产品的香气、口感与整体接受度均得到显著提升。该混合发酵蔬菜汁饮品具备适配目标消费群体的潜力，同时具有较高的深入研究价值。