The determination of anions and metals in kombucha using ion chromatography and inductively coupled plasma optical emission spectroscopy.

摘要

Kombucha is a fermented tea that has been consumed since the time of the Tsin Dynasty in China.1 It is produced from the modification of sweetened tea by a symbiotic culture of bacteria and yeast. The culture is called a SCOBY and it initiates several transformative chemical processes in sweetened tea that produces ethanol, organic acids, and acetic acid. The purpose of this research project was to develop quality analysis and control methods for a regional kombucha manufacturer. Inorganic and organic ions and metals were determined in finished kombucha, source materials, commercially available teas, and competitor beverages. Sample treatment assays and instrument methods were developed for these compounds. Ion Chromatography (IC) was used to determine organic and inorganic anions while Inductively Coupled Plasma Optical Emission Spectroscopy (ICPOES) was used to determine metals. Anion concentrations of acetate, chloride, nitrate, phosphate, and sulfate varied between each kombucha flavor. This is likely due to different additives, such as; fruit juice, spices, and extracts. Acetate was found in the highest concentration, which is to be expected because acetic acid is a major by-product of sweet-tea fermentation. Analyses showed that the concentrations of aluminum, calcium, iron, magnesium, manganese, and sodium were relatively consistent across 10 different kombucha flavors. Concentrations in the kombucha flavors were similar to concentrations in the competitor beverages and brewed tea samples. In general, calcium, magnesium, and sodium were the most prevalent metals found in the 10 kombucha flavors.;1Roche, J. Kombucha James Roche http://users.bestweb.net/~om/~kombu/roche.html (accessed May 1, 2015).