Comparative analysis of Citri reticulatae pericarpium: Revealing the nonvolatile compounds transformation and optimizing drying processes

The effects of different drying temperatures and air velocities on the drying behavior, quality, and nonvolatile compounds (NVCs) transformation of Citri reticulatae pericarpium (CRP) were investigated. Results showed that the drying time shorted with increasing drying temperature and air velocity; however, the energy consumption was lowest at 65 celcius. The rapid moisture migration led to a porous structure, increased frangibility and thickness, and decreased hardness. Rising air velocity increased the curl, which properly protected the volatile oils. The increased drying temperature also changed the NVCs, as evidenced by the reduced amino acid, ester, phenolic, and carbohydrate content in CRP. As for hesperidin, it reaches its maximum at 65C, caused by the transformation of flavonoid metabolism. Furthermore, the analysis demonstrated that temperature and air velocity have interactions besides the individual effects. By considering both drying time and quality, the desired CRP products were obtained at 65C and 6 m/s through a comprehensive evaluation.