A Comparative Analysis of the Flavor, Aroma, and Compositions in Three Levels of Stir-Frying Cyperus rotundus Using E-Tongue, E-Nose, and HS-GC-MS

Cyperus rotundus (CR) is the dry rhizome of the Cyperaceae plant Cyperus, which is widely used in food processing, such as curry, pickling spices, and baking goods, as well as medicinally after stir-frying. The level of stir-frying (slightly stir-frying, stir-frying yellow, and stir-frying black) has a direct impact on the flavor, aroma, and pharmacological effects of the food. However, the distinctions between various levels of stir-frying have not been studied. The purpose of this study was to develop a method that combines electronic tongue, electronic nose, and HS-GC-MS to elucidate the flavor and aroma differences between three types of stir-fried CR and to identify aroma difference components. As the degree of stir-frying increased, the sweet, bitter, astringent, and umami flavors of the sf-CR diminished while the aroma intensified. Among the 33 differential compounds, pyrazines, D-limonene, camphene, trans-verbenol, and ponocarvone were the most significant aroma-causing components. This method effectively differentiates the three levels of sf-CR and provides a foundation for the use of sf-CR in food processing and pharmaceutical applications.