CHAPTER ONE
INTRODUCTION
Neem oil is a vegetable oil pressed from the fruits and seeds of the neem (Azadirachta indica) an evergreen tree which is endemic to the Indian subcontinent and has been introduced to many other areas in the tropics. It is the most important of the commercial available products of neem for organic farming and medicines.
Neem oil varies in colour; it can be golden yellow, yellowish brown, reddish brown, dark brown, greenish brown, or bright red. It has a rather strong odour that is said to combine the odours of peanut and garlic. It is composed mainly of triglycerides and contains many triterpenoid compounds, which are responsible for the bitter taste. It is hydrophobic in nature; in order to emulsify it in water for application purposes, it must be formulated with appropriate surfactants.
Neem oil is not used for cooking purposes. In India, it is used for preparing cosmetics (soap, hair products, body hygiene creams, hand creams) and in Ayurvedic, Unani and folklore traditional medicine, in the treatment of a wide range of afflictions. The most frequently reported indications in ancient Ayurvedic writings are skin diseases, inflammations and fevers, and more recently rheumatic disorders, insect repellent and insecticide effects.
Neem (Azadirachta indica A, Juss) is one of the very few trees known in the Indian subcontinent. This tree is belonged to Meliceae family, and grows rapidly in the tropic and semi-tropic climate. It is also observed that this tree could survive in very dry and arid conditions.
Neem tree is an evergreen tree, but it may become leafless for a short period in certain conditions. Neem tree also found in Indonesia in several areas such as Bali, Lombok, West Java, East Java (Situbondo, Ngawi), Central Java, and Nusa Tenggara Barat. All parts of Neem plant such as leaves, bark, Flower, fruit, seed and root have advantages in medical treatment and industrial products. Its leaves can be used as drug for diabetes, eczema and reduce fever. Barks of Neem can be used to make toothbrush. Neem roots has an ability to heal diseases and against insects (Khraisha, 2000) however, this tree is to very popular in Indonesia because it is only used as canopy tree.   Neem seed is a part of “Neem tree which has high concentration of oil. Neem oil is widely used as insecticides, lubricant, drugs for variety of diseases such as diabetes and tuberculosis (Johnson, 1996). This oil could also prolong leather goods when it is applied on them.
There are several methods to obtain Neem oil from the seeds like mechanical pressing, supercritical fluid extraction, and solvent extraction. Mechanical extraction is the most widely used method to extract Neem oil from “Neem seed. However, the oil produced with this method usually has  a low price, since it turbid and contains a significant amount of water and metals contents. Extraction using supercritical fluid, the oil produced has very high purity; however the operating and investment cost is high. Extraction using solvent has several advantages. It gives higher yield and less turbid oil than mechanical extraction, and relative low operating cost compared with supercritical fluid extraction.