背景:康普茶是一种广泛消费的发酵饮料,通过用细菌和酵母的共生培养物(SCOBY)发酵甜茶而产生。由于微生物组成的不可预测的变化,SCOBY中微生物群落的动态性质可能对生产规模扩大提出挑战。使用鉴定的发酵剂菌株是控制微生物组成的新策略,从而确保不同批次的均匀发酵质量。然而,这些微生物菌株的培养和维护仍然存在挑战。这项研究检查了微囊化红茶菌发酵发酵剂的潜力,特别是糖杆菌属,短小杆菌和酿酒酵母,通过喷雾干燥和冷冻干燥。
结果:采用麦芽糊精和阿拉伯树胶-麦芽糊精作为载体试剂。我们的结果表明,喷雾干燥和冷冻干燥的样品都符合物理化学标准,具有较低的水分含量(2.18-7.75%)和相对较高的溶解度(65.75-87.03%),适合食品应用。与喷雾干燥(74.92-78.66%)相比,冷冻干燥在保持细菌菌株活力(88.30-90.21%)方面表现出更高的有效性。此外,冻干的发酵剂菌株在促进红茶菌发酵方面表现出类似的功效,与SCOBY组相比。观察结果包括pH值降低,乙酸生产,α-淀粉酶抑制和提高总多酚和黄酮含量。此外,生物活性,包括抗氧化潜力和体外酪氨酸酶抑制活性,以相同的模式增强。冻干菌株在三个月的保存中表现出一致的康普茶发酵能力,无论在30或4°C下的储存温度如何。
结论:这些发现突出了冻干发酵剂对红茶菌生产的适用性,实现微生物成分控制,降低污染风险并确保一致的产品质量。©2024化学工业学会。
BACKGROUND: Kombucha is a widely consumed fermented beverage produced by fermenting sweet tea with a symbiotic culture of bacteria and yeast (SCOBY). The dynamic nature of microbial communities in SCOBY may pose challenges to production scale-up due to unpredictable variations in microbial composition. Using identified starter strains is a novel strategy to control microorganism composition, thereby ensuring uniform fermentation quality across diverse batches. However, challenges persist in the cultivation and maintenance of these microbial strains. This study examined the potential of microencapsulated kombucha fermentation starter cultures, specifically Komagataeibacter saccharivorans, Levilactobacillus brevis and Saccharomyces cerevisiae, through spray-drying and freeze-drying.
RESULTS: Maltodextrin and gum arabic-maltodextrin were employed as carrier agents. Our results revealed that both spray-dried and freeze-dried samples adhered to physicochemical criteria, with low moisture content (2.18-7.75%) and relatively high solubility (65.75-87.03%) which are appropriate for food application. Freeze-drying demonstrated greater effectiveness in preserving bacterial strain viability (88.30-90.21%) compared to spray drying (74.92-78.66%). Additionally, the freeze-dried starter strains demonstrated similar efficacy in facilitating kombucha fermentation, compared to the SCOBY group. The observations included pH reduction, acetic acid production, α-amylase inhibition and elevated total polyphenol and flavonoid content. Moreover, the biological activity, including antioxidant potential and in vitro tyrosinase inhibition activity, was enhanced in the same pattern. The freeze-dried strains exhibited consistent kombucha fermentation capabilities over a three-month preservation, regardless of storage temperature at 30 or 4 °C.
CONCLUSIONS: These findings highlight the suitability of freeze-dried starter cultures for kombucha production, enable microbial composition control, mitigate contamination risks and ensure consistent product quality. © 2024 Society of Chemical Industry.