Vegetable oil is the lipidic extract of an oleaginous plant, i.e. a plant whose seeds, fruit, or nuts contain lipids.
Extracting vegetable oils
Cold pressing
Cold pressing is an entirely mechanical extraction method that is carried out at a low temperature to preserve all essential fatty acids, vitamin E, and natural antioxidants, and thereby free it from the need for additives.
The first extraction, called the “first pressing,” produces a pure oil-based “fruit juice.”
Differences between oily macerates and vegetable oil
A vegetable oil is obtained during the initial cold pressing of a nut, fruit, or oil seed. This oil therefore resembles an oily juice. However, some plants that are beneficial to health as an oil cannot produce oil by way of pressing. These are called oily macerates or macerated oils.
Macerated oils are produced by way of a fairly simple process that has been around since the dawn of time:
- Select a plant containing the desired active ingredients
- Macerate part of the plant (flowers, seeds, stem) for several weeks in a common vegetable oil (such as sunflower oil)
- Filter the mixture to obtain a vegetable oil that is packed with the active ingredients contained in the plant
Oily macerates can be used like any other vegetable oil.
Hot pressing vegetable oils
From a purely commercial standpoint, vegetable oils can be hot pressed mechanically at temperatures of 80° to 120°C. During the process, basic plant materials undergo a series of highly invasive chemical treatments (refining, degumming, deodorization, decolorization) that remove most of its vitamins, essential fatty acids, and antioxidants. These extracts lose all their cosmetic properties and nutritional qualities and are sometimes referred to as “unrefined oil,” “raw oil,” or “natural oil.”
How do you recognize a high-quality vegetable oil?
A vegetable oil can only be labeled as “virgin” if it meets the specific criteria defined by legislation:
- First cold pressing
- Clarification by physical or mechanical means
- No physical or chemical refining
Virgin oils can have acidity levels of up to 3%, while the acidity level of an extra virgin oil must not exceed 1%. The term “extra virgin” is only used for olive oil.
To receive a Certified Organic or 100% Organic label, vegetable oils must be produced in farms that are free of synthetic chemicals and whose crops are located in areas that are sheltered from external contamination. Obtained exclusively by way of mechanical cold pressing, certified organic vegetable oils are labeled to allow them to be traced from the farm to your table.
The “organic” certification is awarded by certified inspection agencies that verify compliance with all applicable regulations.
Using vegetable oils
Cosmetic uses
Use as dietary supplements
Storing vegetable oils
Blending vegetable oils and essential oils.
A vegetable oil is a fatty substance obtained by cold pressing or macerating an oleaginous plant. An essential oil is an “essence” of an aromatic plant obtained by way of steam distillation. The molecules in essential oils have nothing in common with the biochemical composition of vegetable oils. However, as both vegetable oils and essential oils are lipophilic (“fat-loving”), they blend together easily.
Essential oils can be diluted with vegetable oils to obtain powerful aromatic synergies.
For cosmetic uses, 1 to 3% dilution of essential oil in vegetable oil is recommended. For medical uses, dilution levels can span from 20 to even 80%, depending on the toxicity and dermocaustic properties of the essential oils that are chosen.
