Although the antioxidant properties of tropical culinary herbs
are fairly well studied, little is known on the other bioactivities.
The effects of different processing methods are also poorly
studied. The objective of our study was to analyse and evaluate
the antioxidant, antityrosinase and antibacterial properties of
fresh and processed leaves of cashew and betel.
2. Materials and methods
2.1. Herbs
Fresh leaves of A. occidentale and P. betle (Fig. 1) were
purchased from the Chow Kit market in Kuala Lumpur.
Young cashew leaves are pliable and reddish in colour while
betel leaves are bright green and heart-shaped with 2 or
3 pairs of secondary veins.
2.2. Extraction
For antioxidant properties, fresh herbs (1 g) and processed
herbs (0.3 g) were powdered with liquid nitrogen in a mortar
and extracted with 50 mL of methanol with continuous
shaking for 1 h at room temperature. Extracts were filtered
under suction and stored at 4 1C for further analysis.
For antityrosinase and antibacterial activity, fresh herbs
(10 g) and processed herbs (3 g) were powdered with liquid
nitrogen in a mortar and extracted with 100 mL of methanol,
three times for 1 h each time. After swirling continuously in
an orbital shaker, the extracts were filtered and stored at 4 1C
for further analysis.