Three oil palm trunks (tenera type), approximately 25 years old, were obtained from a local plywood manufacturer (Business Espri Co., Penang Province, Malaysia) (Fig. 1A). The palm trees were felled in the rainy season (December) in Malaysia and kept under roof for less than 5 days before sample preparation. A 7-cmthick disk was removed from the middle part of each trunk, which ranged in length from 10-12 m (Fig. 1B), and kept at -20 °C before use. The disks (32-42 cm in diameter) were cut into three parts: inner (a), middle (b), and outer (c) parts, as shown in Figs. 1C and D. Sap was collected by compressing the disks using a laboratory-scale press at 80MPa. The sap was centrifuged at 6,000 rpm for 15 min and the supernatant was stored at -20 °C before use.