Abstract
Kombucha is a fermented beverage made by mixing tea and sugar with bacteria and yeast. When kombucha products contain higher than 0.5% (v/v) alcohol, the legal limit for non-alcoholic drinks, they are classified as alcoholic beverages and are subject to relevant federal and state regulations. An efficient headspace gas chromatography technique utilizing an ionic liquid stationary phase is developed to accurately determine the ethanol content in 18 commercial kombucha samples. The range of ethanol in these products was 1.12–2.00% (v/v). The ethanol concentration of two batches of kombucha was analyzed over a period of 60 days under two different conditions. A significant increase in ethanol content of these samples was observed at 4 and 22 °C. The method accuracy was validated by analyzing 3 NIST ethanol-water standard reference solutions.
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References
Alcohol and Tobacco Tax and Trade Bureau (2016) Kombucha information and resources. https://www.ttb.gov/kombucha/ Accessed 25 April 2017
Blanc PJ (1996) Characterization of the tea fungus metabolites. Biotechnol Lett 18(2):139–142
Cheng C, Liu S, Mueller BJ, Yan Z (2010) A generic static headspace gas chromatography method for determination of residual solvents in drug substance. J Chromatogr A 1217(41):6413–6421
Dufresne C, Farnworth E (2000) Tea, kombucha, and health: a review. Food Res Int 33(6):409–421
Frink LA, Armstrong DW (2016a) The utilisation of two detectors for the determination of water in honey using headspace gas chromatography. Food Chem 205:23–27
Frink LA, Armstrong DW (2016b) Water determination in solid pharmaceutical products utilizing ionic liquids and headspace gas chromatography. J Pharm Sci 105(8):2288–2292
Frink LA, Armstrong DW (2016c) Determination of trace water content in petroleum and petroleum products. Anal Chem 88(16):8194–8201
Frink LA, Weatherly CA, Armstrong DW (2014) Water determination in active pharmaceutical ingredients using ionic liquid headspace gas chromatography and two different detection protocols. J Pharm Biomed Anal 94:111–117
Goh W, Rosma A, Kaur B, Fazilah A, Karim A, Bhat R (2012) Fermentation of black tea broth (Kombucha): I. Effects of sucrose concentration and fermentation time on the yield of microbial cellulose. Int Food Res J 19(1):109–117
Greenwalt C, Ledford R, Steinkraus K (1998) Determination and characterization of the antimicrobial activity of the fermented tea kombucha. LWT-Food Sci Technol 31(3):291–296
Greenwalt C, Steinkraus K, Ledford R (2000) Kombucha, the fermented tea: microbiology, composition, and claimed health effects. J Food Prot 63(7):976–981
Huang K, Han X, Zhang X, Armstrong DW (2007) PEG-linked geminal dicationic ionic liquids as selective, high-stability gas chromatographic stationary phases. Anal Bioanal Chem 389(7–8):2265–2275
Ibañez E, Cifuentes A (2001) New analytical techniques in food science. Crit Rev Food Sci Nutr 41(6):413–450
Jayabalan R, Marimuthu S, Thangaraj P, Sathishkumar M, Binupriya AR, Swaminathan K, Yun SE (2008) Preservation of kombucha tea: effect of temperature on tea components and free radical scavenging properties. J Agric Food Chem 56(19):9064–9071
Jayabalan R, Malini K, Sathishkumar M, Swaminathan K, Yun S (2010) Biochemical characteristics of tea fungus produced during kombucha fermentation. Food Sci Biotechnol 19(3):843–847
Jayabalan R, Malbaša RV, Lončar ES, Vitas JS, Sathishkumar M (2014) A review on kombucha tea: microbiology, composition, fermentation, beneficial effects, toxicity, and tea fungus. Compr Rev Food Sci Food Saf 13(4):538–550
Jeleń H, Gracka A, Myśków B (2017) Static headspace extraction with compounds trapping for the analysis of volatile lipid oxidation products. Food Anal Methods. doi:10.1007/s12161-017-0838-x
Kolb B, Ettre LS (2006) Static headspace-gas chromatography: theory and practice. Wiley, Hoboken
Li H, Chai X, Deng Y, Zhan H, Fu S (2009) Rapid determination of ethanol in fermentation liquor by full evaporation headspace gas chromatography. J Chromatogr A 1216(1):169–172
Liu M, Li H, Zhan H (2014) A novel method for the determination of the ethanol content in soy sauce by full evaporation headspace gas chromatography. Food Anal Methods 7(5):1043–1046
Mason M (1983) Ethanol determination in wine with an immobilized enzyme electrode. Am J Enol Vitic 34(3):173–175
Nummer BA (2013) Kombucha brewing under the Food and Drug Administration model food code: risk analysis and processing guidance. J Environ Health 76(4):8–12
Reiss J (1994) Influence of different sugars on the metabolism of the tea fungus. Z Lebensm Unters Forsch 198(3):258–261
Reva ON, Zaets IE, Ovcharenko LP, Kukharenko OE, Shpylova SP, Podolich OV, de Vera J, Kozyrovska NO (2015) Metabarcoding of the kombucha microbial community grown in different microenvironments. AMB Express 5(1):35
Sievers M, Lanini C, Weber A, Schuler-Schmid U, Teuber M (1995) Microbiology and fermentation balance in a kombucha beverage obtained from a tea fungus fermentation. Syst Appl Microbiol 18(4):590–594
Snow NH, Bullock G (2010) Novel techniques for enhancing sensitivity in static headspace extraction-gas chromatography. J Chromatogr A 1217(16):2726–2735
Sreeramulu G, Zhu Y, Knol W (2000) Kombucha fermentation and its antimicrobial activity. J Agric Food Chem 48(6):2589–2594
Vīna I, Semjonovs P, Linde R, Denina I (2014) Current evidence on physiological activity and expected health effects of kombucha fermented beverage. J Med Food 17(2):179–188
Weatherly CA, Woods RM, Armstrong DW (2014) Rapid analysis of ethanol and water in commercial products using ionic liquid capillary gas chromatography with thermal conductivity detection and/or barrier discharge ionization detection. J Agric Food Chem 62(8):1832–1838
Acknowledgements
The authors gratefully acknowledge financial support from the Welch Foundation (Y0026). Moreover, we would like to thank Shimadzu Scientific Instruments for instrumental support.
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Mohsen Talebi declares that he has no conflict of interest. Lilian A. Frink declares that she has no conflict of interest. Rahul A. Patil declares that he has no conflict of interest. Daniel W. Armstrong declares that he has no conflict of interest.
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Talebi, M., Frink, L.A., Patil, R.A. et al. Examination of the Varied and Changing Ethanol Content of Commercial Kombucha Products. Food Anal. Methods 10, 4062–4067 (2017). https://doi.org/10.1007/s12161-017-0980-5
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DOI: https://doi.org/10.1007/s12161-017-0980-5