Ebersole Blake, Liu Ying, Schmidt Rich, Eckert Matt, Brown Paula N
NaturPro Scientific LLC, 10541 Brookview Dr., Carmel, IN 46032.
British Columbia Institute of Technology, Centre for Applied Research and Innovation, Burnaby, BC, Canada.
J AOAC Int. 2017 May 1;100(3):732-736. doi: 10.5740/jaoacint.16-0404. Epub 2017 Feb 21.
Kombucha is a fermented nonalcoholic beverage that has drawn government attention due to the possible presence of excess ethanol (≥0.5% alcohol by volume; ABV). A validated method that provides better precision and accuracy for measuring ethanol levels in kombucha is urgently needed by the kombucha industry. The current study validated a method for determining ethanol content in commercial kombucha products. The ethanol content in kombucha was measured using headspace GC with flame ionization detection. An ethanol standard curve ranging from 0.05 to 5.09% ABV was used, with correlation coefficients greater than 99.9%. The method detection limit was 0.003% ABV and the LOQ was 0.01% ABV. The RSDr ranged from 1.62 to 2.21% and the Horwitz ratio ranged from 0.4 to 0.6. The average accuracy of the method was 98.2%. This method was validated following the guidelines for single-laboratory validation by AOAC INTERNATIONAL and meets the requirements set by AOAC SMPR 2016.001, "Standard Method Performance Requirements for Determination of Ethanol in Kombucha."
康普茶是一种发酵非酒精饮料，因其可能含有过量乙醇（体积分数≥0.5%酒精；ABV）而引起了政府的关注。康普茶行业迫切需要一种经过验证的方法，用于更精确、准确地测量康普茶中的乙醇含量。本研究验证了一种测定市售康普茶产品中乙醇含量的方法。采用顶空气相色谱法（GC）和火焰离子化检测法测定康普茶中的乙醇含量。使用了一条ABV范围为0.05%至5.09%的乙醇标准曲线，相关系数大于99.9%。方法检测限为0.003% ABV，定量限为0.01% ABV。相对标准偏差（RSDr）范围为1.62%至2.21%，霍维茨比率范围为0.4至0.6。该方法的平均准确度为98.2%。本方法按照AOAC INTERNATIONAL的单实验室验证指南进行了验证，符合AOAC SMPR 2016.001《康普茶中乙醇测定的标准方法性能要求》规定的要求。
