Naringin and naringenin determination and control in grapefruit juice by a validated HPLC method

The main goal of this work was to develop and validate a fast, effective HPLC method for the simultaneous determination and control of naringin and naringenin, in several samples of citrus juices, namely, natural and commercial grapefruit and orange juices. The reason for developing this HPLC procedure is to control the debittering process using naringinase. A successful resolution and retention times were obtained with a C18 reversed phase column, at a 1 mL min−1 flow rate, with a gradient of acetonitrile:water and at the temperature of 25 °C. The method was linear in the working range of 55–95 μg mL−1 for naringin and 10–60 μg mL−1 for naringenin. Repeatability was determinate at three concentration levels obtaining a RSD (%) always lower than 2.5%, a limit of detection (LOD) and a limit of quantification (LOQ) of 2.83, 8.57 and 1.11, 3.37 μg mL−1 for naringin and naringenin, respectively, were obtained.