COLD PRESSED OIL
Naturally, oil seeds can pressed to extract oil (Like pressing juice from a fruit).
Sesame seeds, Coconut, Groundnut/Peanut, Olive, etc are a few from which oil can be extract by just pressing, which is a natural process.
Standard Cold-Pressed Oil Processing Steps
- Oil seeds are clean and dried to remove any moisture in it.
- Natural drying using sunlight
- The seeds are then crush using a slow grinding machine with a Pestle and Mortar. (Just like pressing juice from a fruit)
- Natural squeezing
- The oil extract then filter to separate the oil from the seed pulp
- Natural gravity sedimentation
“Chekku”, “Ghani” & “Kolhu” oil are some colloquial words use in India to describe Cold-pressed oil machines.
This is the natural method of extracting oil. Since no heat is apply during the extraction (unlike refine oils) this natural method know as cold-pressed.
In ancient times, a cow use to grind oil seeds to make oil. These days we use a mechanical oil pressing machine.
Extraction, isolation of oil from animal by way of-products, fleshy fruits along with the olive and palm, and oilseeds which include cotton seed, sesame seed, soybeans, and peanuts.
Oil Extracted via Following Preferred Methods:
Rendering use with animal products and oleaginous fruits, mechanical pressing, for oil-bearing seeds and nuts, and extracting with volatile solvents, employ in large-scale operations for a more complete extraction than is viable with pressing.
Rendering at the beginning impl the application of heat, in its maximum primitive form, it’s far practiced by means of heaping fruits consisting of olives in piles exposed to the sun and collecting the oil that exudes.
A similar, somewhat more advance process is use to extract oil from palm fruits by boiling in water, then skimming the oil from the surface.
Whale blubber is cut into small portions and heat in vats (tryworks) or cook in steam digesters, the oil is accrues by way of draining or skimming.
Many oil-bearing seeds and nuts are breaks up by means of grinding, flaking, or rolling, then subjected to mechanical pressing to free up the oil. The modern continuous screw press exerts pressures as excessive as 30,000 pounds per square inch.
In modern press extraction, oilseeds or nuts are wipe clean, and the shells or hulls remove, the kernels or meats are ground to a coarse meal that is press with or without preliminary heating.
Cold-pressed oil, also referred to as cold-drawn, or virgin, oil, is purer and has a better flavour than oil expressed with the aid of heat. After pressing the meals made from oily seeds or nuts, the ultimate cake carries about 5 to 15 percent oil.
Maximum of the oil found in these residues, and in meals made from seeds and nuts that naturally incorporate little oil, can be eliminate via extraction with volatile solvents, especially petroleum benzin.
The solvent is percolate through the meal, dissolving the oil, that is subsequently recover from the solution by using evaporating the solvent. The solvent is likewise recover and used yet again.
With many oil-bearing seeds and nuts, rendering will no longer unlock the oil from the cellular structures wherein it’s miles held.
In these cases the cellular partitions are damage through grinding, flaking, rolling, or pressing underneath high pressures to free up the oil.
The overall sequence of modern operations in pressing oilseeds and nuts is as follows:
- The seeds are pass over magnetic separators to do away with any stray bits of metal
- If important, the shells or hulls eliminate
- The kernels or meats are transform to coarse meal through grinding them between groove rollers or with unique styles of hammer turbines
- They may be press in hydraulic or screw presses without or with preliminary heating, depending at the sort of oil-bearing material and the exceptional of oil desire.
Oil expressed without heating consists of the least quantity of impurities and is often of edible high-quality without refining or in addition processing. Such oils are know as cold-drawn, cold-pressed, or virgin oils.
Pressing the coarse meal at the same time as it is heat removes extra oil and additionally more portions of nonglyceride impurities which include phospholipids, coloration our bodies, and unsaponifiable matter. Such oil is greater enormously colour than cold-pressed oils.
Other oils seeds such as rapeseed (canola), soybean, corn, sunflower, safflower, etc cannot yield oil through natural extraction techniques.
These vegetable oils were non-existent until the early 1950s, when chemical treatment and processing (refining) techniques allow them to be extract.
Because these oils are chemically extract, they need to be refine. Our bodies weren’t mean to consume chemically extract refine oil.
Refined Oil Processing Steps
Oil seeds (groundnuts, sesame, coconut, sunflower seeds, etc) are crush and then heat in a steam bath – 110 to 2000 Celsius
The mixture of oil and seed pulp is then chemically process with a hexane solvent to extract any residual oil from the pulp. (Hexane is produce by refining crude petroleum oil)
This resulting mixture then put through a centrifuge and phosphate use to separate the oil from the seed residues.
Water degumming: Here water is added. This reaction with water results in hydrate phosphatides, which can separate by decantation or by centrifuges.
Neutralization: The resulting product from the above steps contains fatty acids, phospholipids, pigments, waxes, etc.
These impurities are remove by using caustic soda (sodium hydroxide) or soda ash (sodium carbonate). The refined oil is lighter in color, less viscous and easily prone to oxidation.
Caustic Soda/Soda Ash
The bleaching: This is done to remove off colour materials. Bleaching agents are use in this process.
Deodorization: Pressurize steam at very high temperatures (500F) is use to remove volatile compounds, which cause off odours and taste in the final product.
This process kills all the nutrition and alters the molecules in unfavourable ways – making it very unhealthy.
This chemical process yields “oil” that is very unhealthy, but very consistent in terms of colour, smell, odour and shelf life.
When you take a natural food product and expose it to multiple chemical processes, how can it be natural and healthy?
Multiple studies have linked consumption of refined oils to many chronic diseases. Chemically extracted oils lead to inflammation within the body, elevated blood triglycerides and an impaired insulin response, etc.
These days Refined oils are advertise as “Vitamin +”. Oil should be a natural product! What add to make it Vitamin+ ?
Making oil is such a simple process. Then why do Refined oils exist?
Seeds such as rapeseed (canola), soybean, corn, sunflower, safflower, etc cannot yield oil through natural extraction techniques. To extract oil from these seeds, only chemical refining process works.
Since 1950s, manufacturers also started using refining process for groundnut, sesame, coconut, etc.
Refined oil extraction has higher oil yield. For example, in cold pressed method we need 2.5kg of groundnuts to make 1 litre of groundnut oil.
The refined process will extract 1 litre of oil from 2.2 kg of groundnuts. Since refined oil is neutralizes for taste, colour and odour, very low quality oil seeds are use. (Cold pressed oil has to use only good quality oil seeds; otherwise, a consumer will indentify the lapse in quality).
This is the most shocking part. Palm oil constitutes nearly 45% of edible oil consumed in India. Palm oil is the most consumed oil. How?
Nobody goes to the grocery store to buy palm oil and there isn’t palm oil in grocery store shelves, yet we consume so much palm oil.
Cheap and neutral oils such as palm oil, cotton seed oil, etc are mix with other oils for profits. This is a widespread and accepted “Oil blending” practice in the oil industry.