Vegetable fats as well as animal fats are a daily element of our diet.
Vegetable fats are considered "good fats" because for the most part, they are a source of unsaturated fatty acids, which have a scientifically proven, positive effect on the human body. Can all vegetable fats be considered valuable? And how do they differ from those of animal origin?
What are vegetable fats?
Vegetable fats, as well as animal fats, are lipids that are one of the basic macronutrients present in the diet of every human being.
1 g of fat provides the body with 9 kcal.
Vegetable fats are obtained from the seeds or pulp of oilseeds by appropriate processes such as pressing or extraction.
They are made of glycerol and free fatty acids, and their characteristic feature is that they do not dissolve in water.
It is commonly believed that vegetable fats are these "healthy" fats. Apart from some exceptions, such as palm oil, this statement can be considered to be the most correct.
What does the consistency of vegetable fats depend on?
Vegetable fats can be in the form of oil or have a solid consistency. What is the reason?
The consistency of fat depends on the profile of fatty acids contained in it, namely on saturated fatty acids (EFAs) and unsaturated fatty acids (EFAs, PUFAs).
In fats of plant origin, unsaturated fatty acids are the leaders, which mostly have a liquid consistency, e.g. rapeseed oil or soybean oil.
However, there are vegetable fats that have a composition similar to animal fats and contain significant amounts of saturated fatty acids and thus stand out for their solid form. Such fats include palm or coconut oil.
Methods of obtaining vegetable fats
To extract the fat, the oilseeds are subjected to a pressing or extraction process. Sometimes both methods are also combined.
Pressing, i.e. obtaining oil by squeezing (usually using a press), can be done hot or cold. As the name suggests, with the "hot" method, seeds or plants are heated to a temperature of about 90 degrees Celsius and then pressed. In turn, in the "cold" version, the temperature of plants and seeds does not change.
Niekiedy oleje roślinne poddawane są także rafinacji, czyli oczyszczaniu.
Unrefined oils are distinguished by their intense taste and smell, but they have a much lower durability and smoke point than refined oils. Unrefined oils are great when consumed cold, but they are not suitable for heat treatment. In turn, refined oils have a high smoke point and better durability, which is why they are commonly used in the kitchen i.a. for frying.
It is also worth separating virgin oils, which are obtained by mechanical methods in appropriate conditions, which at the same time protect the manufactured product against changing properties. The temperature of this process usually does not exceed 50 degrees Celsius.
Sources of vegetable fats and their examples
Vegetable fats, as you can easily guess, are obtained from plants and seeds, sometimes also from nuts. They differ in taste and properties.
It is worth using a variety of vegetable fats in the diet, such as:
- olive oil,
- canola oil,
- olej sojowy,
- evening primrose oil,
- hemp oil,
- sunflower oil,
- pumpkin seed or grape seed oil,
- walnut oil,
- linseed oil.
Vegetable fats also include palm oil, which is rich in trans isomers, and these adversely affect the human body and health, as well as coconut oil, which is a source of saturated fatty acids. However, coconut oil contains desirable (especially by athletes) medium-chain MCT fatty acids and many other valuable nutrients, which is why it is a frequent visitor to our kitchens.
It is also worth paying attention to margarines, which are a mixture of water and fats, often vegetable. We can distinguish:
- Soft margarines in which trans fats constitute no more than 1% of total fat. They are often enriched, e.g. in vitamin D and A,
- hard margarines, which are produced by traditional hydrogenation. They contain much more trans isomers (usually 1 to 2 g per 100 g of product).
The role and use of vegetable fats
Fats are one of the most important macronutrients present in the daily human diet. They should cover 20-35% of daily energy needs, depending on physical activity and lifestyle.
The role of vegetable fats
Fats support the work of the nervous system, as well as the cardiovascular system. They play an important role in the proper functioning of cell membrane structures. They protect internal organs, are a source of energy, as well as can positively affect the work of the brain. They are also responsible for the absorption of vitamins A, D, E and K. Fat is also a carrier of taste.
Vegetable fats differ in composition, but most of them combine a high content of essential fatty acids.
The concept of essential fatty acids includes fatty acids such as omega-3 or omega-6, which must be supplied with food, because the body can not synthesize them on its own, as well as omega-9 fatty acids, which can be produced in the body, but only if the body contains adequate amounts of omega-3 and omega-6. Most of these compounds are found in cold-pressed vegetable oils
EFAs have a positive effect on the body and are called "good fats" because they can, i.a. have a positive effect on brain function or heart function. However, it is worth remembering that the right proportions of omega-3 to omega-6 acids are extremely important to maintain health. The ideal balance is between 1:2 and 1:5.
The use of vegetable fats
Vegetable fats are used both in the kitchen and in cosmetics, and even in aromatherapy.
In the kitchen, they are used for heat treatment of dishes incl. for frying or baking. They are also the basic ingredients of sauces and dressings.
In cosmetics, however, they are added to lotions, creams and shampoos, as well as other care products that are supposed to lubricate the skin and protect it from external factors.
Vegetable fats are also part of dietary supplements, because they facilitate the absorption of vitamins, especially those soluble in fats.
Vegetable and animal fats - differences
Vegetable fats are mostly a valuable source of polyunsaturated and monounsaturated fatty acids, including EFAs, which have a positive effect on the work of the whole system, support the circulatory system and brain function, as well as have a positive effect on the condition of the skin, hair and nails.
In turn, animal fats are a wealth of saturated fatty acids, which are worth limiting in the diet, because their excessive supply may help to increase the risk of developing serious diseases.