Abstract
Pandan leaves are one of the most popular herbs from Southeast Asia. Scientifically, the herb is demonstrated to contain a variety of bioactive compounds that are beneficial for human health. For extraction and preservation purposes, oven drying is one of the critical pre-treatment steps. Therefore, in this study, response surface methodology was applied to optimize drying condition to maximize the contents of flavonoids and phenolics in the pandan leaf extract. A central composite design was utilized to investigate the effects of two main independent variables, namely drying temperature and drying time. Ultrasound-assisted extraction (UAE) with fixed parameters was employed to enhance the release of target compounds from the dried pandan leaves. The results revealed that the optimal oven-drying condition was 82.14 °C for 9.46 hours, yielding a predicted total flavonoid content of 2.47 mg QE/g DW and a total phenolic content of 2.22 mg GAE/g DW. The experimental results were compared and aligned with the predicted values, demonstrating the adequacy and suitability of the models. The leaf extract at this condition exhibited both antidiabetic and antioxidant activities with IC50 values of 1023.03 µg/mL and 1489.92 µg/mL, respectively for alpha-amylase inhibition and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities. These findings suggest a promising approach for optimizing the oven drying process to maximize the recovery of bioactive compounds from pandan leaves for functional food and nutraceutical applications.
