Simultaneous determination of eleven bioactive constituents in honey-processed licorice by high-performance liquid chromatography-diode array detector and its application from the perspective of processing influence under orthogonal design

Objective: The aim of this study was to develop a reliable approach to simultaneously quantify 11 markers and explore the quality variation in honey-processed licorice. Materials and Methods: A high-performance liquid chromatography-diode array detector method was developed for the simultaneous determination of 11 markers (nine flavonoids and two triterpenoid saponins) in honey-processed licorice. The changes to the 11 markers in honey-processed licorice were investigated using an orthogonal design with three input factors. Results: The established method was precise, accurate, and sensitive enough for the simultaneous quantitative evaluation of 11 markers in honey-processed licorice. Intuitive analysis and variance analysis revealed that (1) the soaking time of crude licorice, stir-frying temperature, and stir-frying time remarkably influenced the content of liquiritin apioside, signifying the decomposition of liquiritin apioside to liquiritin or transformation of liquiritin apioside to isoliquiritin apioside, (2) stir-frying temperature significantly influenced licorice-saponin G2, (3) stir-frying temperature was the most important factor of the three input factors, (4) in terms of composition, honey fried licorice had significant effects on two components, namely liquiritin apioside and licorice-saponin G2. Conclusions: Honey processing influenced the content of the 11 licorice analytes differently. This paper highlights the first report on how the quality of honey-processed licorice varies under different processing conditions and suggests the optimal levels of the investigated three factors as A2B2C3 according to the degrees of influence of these factors on the 11 components. Specifically, the soaking time of crude licorice with honey solution, stir-frying temperature, and stir-frying time were 40 min, 100°C, and 20 min, respectively.