Determinación y cuantificación de componentes microbiológicos y ácido glucurónico en diferentes marcas de té kombucha

Abstract

Kombucha tea is a beverage that is made by fermenting sugared tea using a
symbiotic culture of bacteria and yeasts. The beneficial effects of kombucha are
due to the presence of microbiological and chemical compounds that act
synergistically. Specifically, bacteria present in kombucha, like the ones from the
genus Acetobacter and Gluconobacter, as well as yeasts from the genus
Saccharomyces, along with glucuronic acid (GlcUA), contribute to the protection of health. Kombucha consumption has been associated with effects like the reduction of cholesterol levels and blood pressure, as well as the improvement of liver, immune, and gastrointestinal functions.
The aim of this research was to determine and quantify the microbiological
compounds and glucuronic acid present in six kombucha tea brands, where
microbiological presence was detected through various growth mediums, like EMB for the recognition of Gram-negative bacteria; Standard Methods Agar for the quantification of aerobic microorganisms; MRS Agar for the recognition of lactic acid bacteria; Tripticase Soy Agar for the recognition of aerobic and anaerobic microorganisms; and UV-visible spectrophotometry to determine the concentration of GlcUA.
Variations in the quantities of CFU/mL and concentrations of GlcUA were found
among the kombucha brands. Mainly, bacilliform bacteria and yeasts were
observed. The brands GT’s Enlightened Synergy and RGB (craftmade) presented
the highest number of colonies, with 1.0 x 10 5 CFU/mL each one. The highest
concentration of GlcUA was determined in the brand GT’s Enlightened Synergy,
with 10.01 mg/100 mL. A positive correlation was established between the concentration of GlcUA and CFU/mL. The brands GT’s Enlightened Synergy and RGB (craftmade) presented the highest quantity of CFU, but only GT’s Enlightened Synergy had the highest
concentration of GlcUA, placing it as the optimal kombucha tea brand to be
consumed, according to this research. It was shown that GlcUA is present in all
kombucha tea brands, but not all of them have the microbiological compounds that are declared.
The presence of GlcUA was verified in all brands of kombucha tea, this indicates
that the beverage has certain functionality regardless of its probiotic content.
Concerning their microbiological content claim, not all brands contained the
quantities declared in their labels.
It is suggested to deepen into the GlcUA requirements in human beings, as well as being able to quantify other important tea compunds such as sucrose and compare them with that declared in their nutritional labels.

Date of Award	2019
Original language	Spanish
Supervisor	Anayansi Escalante Aburto (Supervisor) & Joselina Huerta Oros (Supervisor)