2.1. Materials
Palm kernels were collected from Malpom Sdn. Bhd., Nibong Tabal, Pinang. A blender (Matsushita Electric Industrial Co., Ltd. MX-X57) was used to grind palm kernel. Commercial liquefied carbon dioxide (purity, 99.9%) was purchased from Nippon Sanso, Tokyo. The n-hexane of AR Grade was obtained from Wako Chemicals, Osaka.