Cold pressed method is one of the best methods to extract essential oils. It is a method of mechanical extraction where heat is reduced and minimized throughout the batching of the raw material. Cold pressed method is also known as scarification method. No external heat is required to let the process go, rather the high temperature to carry out the process is obtained internally. Though it is not considered a practical method of extraction for all vegetable oils but it is highly regarded as the extraction method of choice.
Process
In this method the peel of the fruit is penetrated while rolling over a trough. In this way the tiny pouches which contain the essential oil is pierced. After that the whole fruit is pressed to squeeze the juice & the essential oil from the pulp. Then the essential oil rises to the surface of the juice. Here comes the separation process. The Separation method is done from the juice by centrifugation process. The essential oil produced from this method have a very short life to expire.
History of cold-pressed
Cold-pressed' is derived from the German words 'kalt geschlagen', which literally mean 'cold pummeled'. In Switzerland, 'cold-pressed' is defined to mean that oils have not reached temperatures exceeding 50°C. No external heat is supplied to the oil rather the heat is produced to a very high temperature during deodorization. This confirm the fact that no external heat is produced in modern processes. The heat is produced because of the pressure & rotational friction. In Germany oil was produced 100 years ago at home itself by the women, manually. The seeds were poured into a wedge-shaped container & a wooden edge was driven into it. The housewife usually hit the wedge with a wooden mallet & the oil would drip for an hour. This process was continued for every single hour. The temperature ranges from 85 and 95°C for dripping of the oil.
Applications
Cold pressed method is mainly used for extracting essential oils from plants, their seeds and fruits. This method is used to obtain citrus fruit oils such as bergamot, grapefruit, lemon, lime, mandarin, orange and tangerine oils.
