Assessment of convective drying effects on phytochemicals and bioactivities of Camellia quephongensis leaves
摘要
Camellia quephongensis is an endemic species of the Theaceae family from Central Vietnam. This study investigated the impact of different drying temperatures on the chemical composition, antioxidant properties, and enzyme inhibitory activities of C. quephongensis leaves. Additionally, the drying kinetics at various temperatures were analyzed. The results indicated that higher drying temperatures significantly reduced the total drying time, with the logarithmic and Page models effectively characterizing the drying behavior of C. quephongensis leaves. Drying at 45 °C was found to preserve the highest levels of chlorophyll and total phenolic content, which contributed to the strongest antioxidant activity, as evidenced by ABTS and DPPH radical scavenging assays (IC50 values of 78.33 ± 3.24 and 33.80 ± 0.26 µg/mL, respectively). Enzyme inhibition assays further revealed that extracts obtained from the leaves dried at 45 °C exhibited the most potent inhibitory effects on α-amylase and tyrosinase, though their activity remained significantly weaker than that of the standard inhibitors acarbose and kojic acid. This study underscores the importance of optimizing drying temperature to retain the bioactive properties of C. quephongensis leaves. The findings highlight the potential of this species for applications in functional foods and nutraceuticals, paving the way for its utilization as a valuable resource.