Department of Food Chemistry and Phytochemistry, Institute of Applied Biosciences, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131 Karlsruhe, Germany.
Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Freising, Germany.
Carbohydr Polym. 2018 Jun 1;189:296-303. doi: 10.1016/j.carbpol.2018.02.037. Epub 2018 Feb 19.
Water kefir is a beverage which is produced by initiating fermentation of a fruit extract/sucrose solution with insoluble kefir grains. Exopolysaccharides that are formed from sucrose play a major role in the kefir grain formation, but the exopolysaccharides in the kefir beverage and the detailed structural composition of the whole kefir grains have not been studied yet. Therefore, kefir grains and the corresponding kefir beverage were analyzed for exopolysaccharides by multiple chromatographic approaches and two-dimensional NMR spectroscopy. Furthermore, different fractionation techniques were applied to obtain further information about the exopolysaccharides. The exopolysaccharide-fraction of the investigated kefir beverage was predominantly composed of O3- and O2-branched dextrans as well as lower amounts of levans. The insoluble dextrans from the kefir grains were mostly O3-branched and contained an elevated portion of 1,3-linked glucose units compared to the soluble dextrans. The structurally different exopolysaccharides in water kefir suggest the involvement of multiple bacteria.
水克菲尔是一种饮料，通过在不溶性克菲尔粒的水果提取物/蔗糖溶液中引发发酵来生产。蔗糖形成的胞外多糖在克菲尔粒形成中起主要作用，但克菲尔饮料中的胞外多糖和整个克菲尔粒的详细结构组成尚未得到研究。因此，通过多种色谱方法和二维 NMR 光谱法对克菲尔粒和相应的克菲尔饮料进行了胞外多糖分析。此外，还应用了不同的分级技术来获得关于胞外多糖的更多信息。所研究的克菲尔饮料的胞外多糖级分主要由 O3-和 O2-支链葡聚糖以及较低量的莱聚糖组成。克菲尔粒中不溶性葡聚糖主要是 O3-支链的，与可溶性葡聚糖相比，含有较高比例的 1,3-连接的葡萄糖单元。水克菲尔中结构不同的胞外多糖表明涉及多种细菌。
