Sample Preparation. Powdered dried peels of STJ were dried at
40 °C in the oven for 2 h before analysis. The sample was weighed
accurately (0.3 g) and placed into a 50 mL flask containing 25 mL of
methanol/water (70:30, v/v), and then the mixture was extracted in an
ultrasonic bath (Eima Ultrasonics Corp., Germany) at room
temperature for 0.5 h. The methanol solution was filtered through a