Bartholomees Uria, Struyf Tom, Lauwers Olivier, Ceunen Stijn, Geuns Jan M C
Laboratory of Functional Biology, Kasteelpark Arenberg 31, Box 2436, B-3001 Leuven, Belgium.
Laboratory of Functional Biology, Kasteelpark Arenberg 31, Box 2436, B-3001 Leuven, Belgium.
Food Chem. 2016 Jan 1;190:270-275. doi: 10.1016/j.foodchem.2015.05.102. Epub 2015 May 23.
Steviol glycosides are intense natural sweeteners used in foods and beverages. Their acceptable daily intake, expressed as steviol equivalents, is set at 0-4 mg/kg body weight. We report the development and validation of a RP-HPLC method with fluorometric detection of derivatized isosteviol, formed by acid hydrolysis of steviol glycosides. Dihydroisosteviol was used as an internal standard. Using this method, the amount of steviol equivalents in commercial steviol glycoside mixtures and different foods can be directly quantified. The method was successfully tested on strawberry jam, low-fat milk, soft drink, yogurt and a commercial mixture of steviol glycosides. Calibration curves were linear between 0.01 and 1.61 mM steviol equivalents, with a quantification limit of 0.2 nmol. The % RSD of intra-day precision varied between 0.4% and 4%, whereas inter-day precision varied between 0.4% and 5%, for high and medium concentrations, and between 3% and 8% for low concentrations. Accuracy of the analysis varied between 99% and 115%.
甜菊糖苷是用于食品和饮料中的强效天然甜味剂。以甜菊醇当量表示的每日可接受摄入量设定为0-4毫克/千克体重。我们报告了一种反相高效液相色谱法（RP-HPLC）的开发与验证，该方法通过荧光检测甜菊糖苷酸水解形成的衍生化异甜菊醇。二氢异甜菊醇用作内标。使用该方法，可以直接定量商业甜菊糖苷混合物和不同食品中甜菊醇当量的含量。该方法已成功应用于草莓酱、低脂牛奶、软饮料、酸奶以及甜菊糖苷商业混合物的检测。校准曲线在0.01至1.61毫摩尔甜菊醇当量之间呈线性，定量限为0.2纳摩尔。高浓度和中等浓度时，日内精密度的相对标准偏差（%RSD）在0.4%至4%之间，日间精密度在0.4%至5%之间；低浓度时，日内精密度的相对标准偏差在3%至8%之间。分析的准确度在99%至115%之间。
