The oils extracted from nuts, seeds, fruits or vegetables are used for cooking. The process of extracting oil from oilseeds such as sunflower seeds, sesame seeds, coconut, olive or canola without the use of heat in extracting is known as cold pressing.
The process of crushing nuts or seeds and extracting their oil by applying pressure involves cold pressing. This helps in retaining their nutritional quality as well as the flavour of the oil.
In the earlier times, “Ghani” which was a contraption that was long and cylindrical had been used for extracting oil from the seeds. Ghani consisted of a mortar and pestle which was made of wood or stone and extracted oil from oilseeds by applying pressure with the help of a perambulating animal. In this process, a lot of heat was not generated and it was one of the simplest ways of extracting oil.
What is oil refining?
When we go grocery shopping, we tend to observe various labels on the oil packaging which indicates whether the oil is refined, lite, blanched or losorb. This actually means that all the natural nutrients from the oil have been stripped off due to a lot of chemical processes.
The process of purification of oil is known as oil refining. During refining, the proteins, gums, fine seed particles, phospholipids etc. are removed from the oils and due to this, the oil becomes light/ losorbed. Oils are treated with chemicals and heated at high temperatures which neutralize, bleach and deodorize them. The refined oil which is used in modern kitchen consist only of fat and is without any other nutrient. Hence, they are only full of calories without any nutritional value.
All companies prefer selling refined oils because they are budget-friendly, have a reasonably long shelf life and are easily available. These oils are ideally suited for cooking that involves a lot of deep-frying.
Need for cold-pressed oils
The vitamins, proteins, phospholipids, antioxidants, lecithin etc. are retained in cold-pressed oils as they are made using a pressing method where the temperature is controlled. These oils contain all the vital nutrients from natural sources and hence there is no requirement for vitamin supplements.
Refining of oils requires the use of various chemicals such as Sodium Bicarbonate, Hexane, Sodium Hydroxide, Bleaching Agents, etc. and along with these chemicals’ certain preservatives like BHT, BHA, Gallate, Propyl are also introduced. To avoid the consumption of chemicals and live an organic life it is advisable to use cold-pressed oils.
Indian food is rich in spices, flavour and aroma. Virgin oils are totally compatible with Indian cuisine and therefore are the ideal choice for cooking.
Using cold-pressed oils in our daily life helps in reducing carbon footprint as well as are eco-friendly.
The shelf life of cold-pressed oils is about six months which can be increased by storing them in dark places or by refrigerating them. But it is best to consume them at the earliest to enjoy their maximum nutritional value.
Once the bottle of any cold-pressed oil is opened, it should be consumed within the span of 45 days.