Extraction process optimization of anthocyanins from Cercis chinensis flower and their structure characterization

The extract of Cercis chinensis flowers is rich in anthocyanins and possesses good biological activity. In order to efficiently extract the anthocyanins from Cercis chinensis flowers and fully realize their application value, using flowers as the raw material and ethanol as the extractant an ultrasonic-assisted method was adopted to extract the anthocyanins. The extraction conditions were determined through single-factor experiments and response surface optimization. The results showed that the optimal conditions were a liquid-to-solid ratio of 33∶1 mL/g, an ethanol volume fraction of 77%, an ultrasonic power of 326 W, an ultrasonic time of 15 min, and an ultrasonic temperature of 40 ℃. Under these conditions, the content ofCercis chinensis flower anthocyanins was (3.40±0.06) mg/g, which is close to the predicted value. Fourier transform infrared spectroscopy was used to analyze the Cercis chinensis flower anthocyanins, indicating that the molecular structure of the anthocyanins contains hydroxyl groups, oxygen rings, glycosides, phenyl rings, and methoxy groups. In addition, ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was used to identify the components of the Cercis chinensis flower anthocyanins, resulting in the identification of 17 types of anthocyanins and 3 anthocyanin derivatives. The optimal extraction conditions for Cercis chinensis flower anthocyanins were obtained through this research, and the composition of the Cercis chinensis flower anthocyanins was studied, providing a theoretical basis for their application in the food industry.