Characterization of anthocyanins in Gynura bicolor DC using HPLC-Q-Orbitrap MS and its stability during microwave vacuum drying

Gynura bicolor DC ( G. bicolor ) is largely consumed as a vegetable in many parts of the world, and due to its content in anthocyanin can be considered as a health-promoting food. This study aimed to characterize the anthocyanin composition of G. bicolor and compare the effect of microwave vacuum drying (MVD) on the anthocyanin content with that of hot air drying (HAD). Anthocyanins were characterized using high-performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (HPLC-Q-Orbitrap MS), which accurately identified five anthocyanin compounds. Delphinidin 3- O -neohesperidoside is the main anthocyanin compound found in G. bicolor . MVD decreased the drying time by 89% compared to HAD. MVD retained 87% of the total anthocyanins in G. bicolor , compared to 18% retained by HAD. This study revealed that MVD produced high-quality dried G. bicolor products, while exhibiting reduced processing times compared to those achieved using HAD.