Fresh palm fruits were provided by MALPOM Industries Sdn. Bhd palm oil mill in Nibong Tebal, Penang, Malaysia. The fresh fruits were put in vacuum plastic bags and stored at −20 °C. Prior to extraction, a bag of the sample was randomly selected and was left at room temperature for about 30 min. Commercial liquefied R134a gas (purity 99.7%) was supplied in a gas cylinder by Malaysia Oxygen (MOX), Penang. The mesocarp of fresh palm fruits was peeled, sliced and chopped to reduce the sample size using a Kiwi cutter. Samples of chopped mesocarp were oven-dried to reduce its moisture content to a range of about 5–6%. The sample was named as Uncooked-Chopped (UC) sample. Mustapa et al. (2009) reported that the UC sample palm fruits resulted in higher oil yield than cooked fruits. They also reported that the chopped samples gave higher extraction rate as compared to sliced samples. Lau et al. (2006) peeled off the palm mesocarp and dried in the oven at 60 °C until a constant weight was obtained. Prior to the extraction the dried mesocarp was ground into pieces of 1–3 mm length.