Storage :
The seeds, nuts, or plant tissue containing the oil must be properly stored and prepared for extraction to maintain the high quality of the final product. If the oil bearing material is dry, it must be stored so that it remains dry for optimal extraction and quality of the oil. If the oil bearing material is wet- plant tissue, it should be processed for oil extraction immediately after harvest so that the storage time is kept to a minimum. Oils in the presence of water deteriorate rapidly, forming free fatty acids and rancid off-flavors.
Cleaning :
After the oil bearing material has been taken out from storage, the first step in preparing them for oil extraction is to clean them. Cleaning is done so that the oil is not contaminated with foreign materials and that the extraction process can proceed as efficiently as possible. During the process inspection of the seeds is carefully done to remove stones, sand, dirt and spoilt seeds. Dry screening technique is often used to remove all material that is over or under sized. Sometimes washing is also resorted to but it must be avoided as the plant tissue will have to be dried at a later stage.
Heating :
It is the final step for preparing the raw material for oil extraction. Heating leads to increased oil yield. Heating helps in killing those enzymes present in the plant tissue which have a deteriorating effect on oil quality. Moreover, if oilseed cake is to be used for feed or feed, heating is useful as it increases protein availability.
Mustard oil cake also increases plant yields. In a study conducted in Bangladesh, replacing traditional cow dung amendments with mustard oil cake significantly increased produce yield and quality in a variety of vegetables. Plants treated with it yielded, on average, about 25 percent more viable produce than control groups. In the Philippines study, plants treated with mustard oil cake yielded even more compared to the control group: around 65 percent
