Smoke point of oils. What oils to use. How to store oils. Vegetable oils - olive, sunflower, mustard At what temperature does oil boil

Let's see what vegetable oils are and how they should be used.
Sometimes people ask me if it is possible to replace vegetable oil with olive, linseed, etc. in the recipe. To be clear, both olive and flaxseed oils are vegetable oils. A vegetable oil is any oil that is extracted from plants. That is, it is an oil of non-animal origin.

Oils are either refined or unrefined. refined called oil, purified from most impurities. It is pure vegetable fat. It should be remembered that refined oil is purified even from useful impurities. Refined oils are practically odorless, and the taste is weakly expressed. They are ideal for frying, stewing and baking.

unrefined oils are a natural pomace - a mixture of vegetable fat with various impurities. It is unrefined oils that contain the greatest amount of vitamins, trace elements and other nutrients that the human body needs.
Such oils have a pronounced smell and their own specific taste.
Unrefined oils should not be subjected to heat treatment. It is better to eat them raw. You can add unrefined oils to any cold dishes, as well as to hot dishes directly when serving.

Any oils are useful only up to a certain temperature - the smoke point. The smoke point is the temperature at which the oil begins to burn, and toxic substances, including carcinogens, are formed in it.
Unrefined oils, with rare exceptions, have a low smoke point. They have a lot of unfiltered organic particles that quickly start to burn.

Refined oils are more resistant to heat and have a higher smoke point. Do not heat oils to the point of smoking! If you're going to be cooking in the oven, pan, or grill, be sure to use oil with a high smoke point.
I offer you a handy sign that you can print and hang in your kitchen.

Variety is the key to good health. To enrich the diet with nutrients, it is useful to use different types of unrefined cold-pressed vegetable oils.

How to store vegetable oils

Any oils should be stored in a dark, cool place, out of direct sunlight. Bottles must be tightly closed to prevent contact with air. Uncorked bottles of unrefined oils should preferably be stored in the refrigerator. The exception is olive oil, which should be stored at room temperature.
It is necessary to use unrefined oils within a month after uncorking the bottles. If stored incorrectly or for too long, the oil can go rancid and produce toxins (epoxides, aldehydes and ketones). Rancid butter should not be eaten.

Inside a running engine, increased loads are created - high temperature and powerful pressure. One of the main requirements for any engine oil is its ability to maintain its properties at elevated temperatures. There are two indicators by which the quality of the lubricant is determined:

1. Flash point and pour point.
2. Viscosity.

The boiling point of the engine oil must be within the specified range. This is possible only if the lubricant product meets the declared characteristics - the oil must be of high quality. An increase in temperature can lead to damage to the internal combustion engine. Boiling of the lubricant occurs when the power unit is improperly maintained and the load is created above the permissible level.

What does high oil temperature mean?

When characterizing a lubricant, two important indicators of high temperature are considered:

• admissible;
• boiling temperature.

The tolerance factor indicates the optimum oil temperature. There are times when the oil temperature in the engine has reached a working state, and the viscosity change occurs with some delay.

The shorter this time period, the better the lubricant copes with the main function, which consists in thoroughly lubricating the rubbing surfaces of the parts of a running engine. If this condition is met, the wear of the motor will not increase even if it is very hot.

An excessive boiling point is dangerous for the engine. Boiling, bubbling and smoke are unacceptable. The ignition temperature of engine oil is 250°C. At the same time, the lubricant liquefies, a low viscosity index indicates poor-quality lubrication and damage to the entire mechanical part of the engine.

It is unacceptable to increase the temperature of the lubricant in a running engine by more than two degrees in one minute.

If the lubricant burns simultaneously with the fuel, the oil concentration decreases, the exhaust acquires a characteristic color and smell. Lubricant consumption rises sharply. The driver has to constantly fill in new portions.

Neglect of operating temperatures is not recommended, since oil boiling leads to increased wear of the power unit.

oil flash

Flashing of the lubricant occurs when it is mixed with fuel. This effect occurs when a gas flame approaches it. The lubricant heats up, high concentration vapors appear, this leads to their ignition. Ignition and flash characterize such a parameter as the volatility of the lubricating fluid. It directly depends on the type of lubricant and the degree of its purification.

If the flash point has dropped drastically, it means there is a serious problem with the engine. These include:

• malfunctions in the injection system;
• violation of the fuel supply;
• failure of the carburetor.

To find out the flash point of a particular lubricant, the working fluid is heated in a special crucible with the lid closed and open. Fixing the desired indicator is carried out with the help of a lit wick held over a crucible with hot oil.

When it is heated, the concentration of oil product vapors greatly increases. This causes the engine oil to quickly ignite, similar to a fire. Regardless of its type (synthetic or mineral), quality oil not only flares up, it continues to burn.

Oil Pour Point

When solidified, the lubricant becomes inactive, its ductility completely disappears. The grease hardens due to paraffin crystallization. Engine oil at low temperatures dramatically changes its properties. It gains hardness and loses plasticity.

The lubricant must have an optimum temperature index, which is in the range between the flash and solidification factors.

The values ​​of this parameter with a shift, closer to one or another coefficient, leads to a decrease in lubricating properties and loss of efficiency of the internal combustion engine.

Effect of oil viscosity on engine stability

Lubricants are necessary to reduce friction forces between the surfaces of working parts and power unit components. When running dry, jamming occurs, rapid wear and failure of the entire motor. The main requirements include the following functions:

1. Elimination of friction between parts.
2. Free passage of lubricating fluid through all channels of the oil system.

The viscosity index of a lubricant is an important parameter. It is directly dependent on the temperature of the engine and the environment. The viscosity value may deviate from the optimal values ​​due to an increase in temperature inside the motor. To ensure the smooth operation of all systems of the power unit, it is necessary that all work processes take place within acceptable limits.

Determination of viscosity by marking

A branded canister with engine oil from any manufacturer contains detailed information on the viscosity index of the product according to the CAE system. The viscosity designation consists of numeric and alphabetic characters, for example, 5W40.

Here the English letter W refers to the winter parameter. The numbers to the left and right of it are the winter and summer temperatures, respectively. In this range, stable operation of the engine using a specific product is ensured.

The influence of low temperatures on the stability of the engine start

Particular attention is paid to the winter indicator. After all, it is at low ambient temperatures that it is difficult to start the engine “cold”. The constant number 35 is subtracted from the number 5. The result obtained (-30 ° C) is the minimum allowable temperature at which this oil will allow a quick start of the engine. "35" is a constant value for all types of lubricants.

The quick start of a cold internal combustion engine also depends on the following indicators:

• engine's type;
• technical condition of the engine;
• serviceability of the fuel system and battery;
• fuel quality.

What is dangerous high temperature in the engine

Excessive heating of the engine is much more dangerous than its cooling. The oil boils at 250 - 260°C, causing ignition, bubbles and smoke. If this situation continues for a long time, the viscosity of the lubricant drops sharply, and the parts do not receive high-quality lubrication. In this case, the lubricant product forever loses all of its originally useful properties and qualities.

Starting from 125 ° C, the oil evaporates and evaporates with fuel vapor, without getting on the piston rings. The amount of engine oil decreases sharply, which causes the need for constant topping up.

Causes of excessive engine oil heating

Lubricant aging occurs due to oxidative processes occurring in its base. As a result of chemical reactions, negative deposits are released:

1. Nagar.
2. Sludge deposits.
3. Lucky.

These processes are accelerated when exposed to high temperatures.

Carbon deposits are solids that are formed during the oxidation of hydrocarbons. They also include elements of lead, iron and other mechanical particles. Carbon accumulations can cause detonation explosions, glow ignition, etc.

Lacquers are oxidized oil films that form a sticky coating on contact surfaces. Under the influence of high degrees, they are baked. They are made up of carbon, hydrogen, ash and oxygen.

Lacquering impairs the heat transfer of pistons and cylinders, which can cause them to overheat dangerously. Piston grooves and rings, which lie in them due to coking, suffer the most from varnishes. Coking is a harmful mixture of carbon deposits with varnishes.

Sludge deposits are mixtures of emulsion impurities with oxidation products. Their formation is caused by the poor quality of lubricants and a violation of the operating mode of the car.

Conclusion

1. Avoid long trips at high speed.
2. Monitor engine oil temperature.
3. Change the lubricant within the recommended period.
4. Use only proven grades of engine oil in strict accordance with the recommendations of the automaker.

The passport for the car contains detailed information about the brand of engine oil that is suitable specifically for the specific power unit installed on this machine.

Good afternoon, my friends are slimming cooks :) Today I offer you not a recipe, but some background information and food for thought.

We will think about frying in oil. Why is it better to fry in one oil than another? (although, of course, it is best to stew in water or fry in a dry frying pan, but this is not about that now).

One of the important parameters is the "smoke point"! Strange name, isn't it? Let's figure it out. No less important, of course, is the benefit or harm of a particular oil. In more detail about what oil to fry in, taking into account all the parameters, I discuss here.

smoke point This is the temperature at which the oil begins to break down and is no longer suitable for food, as it contains a large amount of free radicals that contribute to the risk of cancer. That is, it does not matter if you are losing weight or not, it is unhealthy in general.

Visually, this can be determined as follows - the oil begins to smoke. It is worth noting that refining the oil increases the boiling point.

The table below shows some approximate smoke points for various oils.

Oil	Fat	smoke point
Unrefined canola oil (rapeseed)	Unrefined canola oil	107°C
Unrefined linseed oil	Unrefined flaxseed oil	107°C
Unrefined sunflower oil	Unrefined safflower oil	107°C
Unrefined corn oil	Unrefined corn oil	160°C
Extra virgin olive oil (extra virgin)	extra virgin olive oil	160°C
Unrefined peanut butter	Unrefined peanut oil	160°C
	Semi-refined safflower oil	160°C
Unrefined soybean oil	unrefined soy oil	160°C
Unrefined walnut oil	Unrefined walnut oil	160°C
hemp oil	Hemp seed oil	165°C
Butter	Butter	177°C
Coconut oil	Coconut oil	177°C
Unrefined sesame oil	Unrefined sesame oil	177°C
Salo	Lard	182°C
Refined canola oil (rapeseed)	Refined canola oil	204°C
High quality (low acidity) extra virgin olive oil	High quality (low acidity) extra virgin olive oil	207°C
Sesame oil	Sesame oil	210°C
Grape seed oil	Grapeseed oil	216°C
Extra virgin olive oil	virgin olive oil	216°C
Almond oil	Almond oil	216°C
Peanut butter	Peanut oil	227°C
Sunflower oil	sunflower oil	227°C
Palm oil	palm oil	232°C
palm kernel oil	palm kernel oil	232°C
Refined peanut butter	Refined peanut oil	232°C
Refined soybean oil	Refined soy oil	232°C
Semi-refined sunflower oil	Semi-refined sunflower oil	232°C
avocado oil	avocado oil	271°C

This article will not be complete if I do not find out what is the temperature in the pan. So,

1. The boiling point of water is 100 degrees, that is, in order for the product to be fried (that is, water evaporates from the oil), and not stewed in a mixture of oil and escaping juice, the temperature should be more than 100 degrees.
2. The golden crust is formed at the temperature at which the chemical reaction between amino acids and sugars begins (Maillard reaction temperature). This temperature = 140-165 degrees. That is, at a temperature of more than 100 degrees, but less than 140, the product is fried, not stewed, but there will be no crust.
3. If the oil has reached the point of smoke (in the literal sense it smokes), then its chemical composition changes and carcinogens are formed in it. Products fried in such oil should not be eaten.

That is, it turns out that it is better to fry in oil, which has a smoke point of 160 degrees or more.

The most dangerous moment is the heating of the pan, it is at this moment that the oil can be overheated, because when we put the cutlet in the pan, the temperature of the oil, of course, will drop. So, be careful at the very beginning of the frying process. That is why for us beginners it is better to pour oil into a cold pan, and when you see that it is hot, immediately start frying.

I look forward to your opinions, objections, advice in the comments.

Vegetable oil, in addition to origin, taste and aroma, has such an important characteristic as boiling point (point), that is, the one at which it starts to burn. When adding oil to a finished dish, we can only follow its obvious characteristics - aroma and taste, and if we are going to fry on it, then it is better to know the boiling point.

Olive oil

Boiling point for extra virgin - 160 °C, for virgin - 210 °C, for pomace (from pomace) - 238 °C, for extra light - 242 °C.

Extra virgin is not suitable for deep frying, but is ideal for dressings, sauces and pastries, as well as for adding to already hot ready-made dishes, such as soups. The rest (depending on the type) are suitable for frying and stewing. See the recipe for spicy carrot cake in olive oil.

Spicy carrot cake with olive oil

avocado oil

Boiling point - 270 °C. One of the most expensive and valuable. Used only in dressings and sauces. You can also fry on it, but in exceptional cases, if, for example, you need to fry the avocado itself.

avocado oil

Soybean oil

Boiling point - 160 ° C (unrefined) and 238 ° C (refined). Refined is suitable for frying and deep-frying, unrefined - for gas stations.

Soybean oil

Corn oil

Boiling point - 178 ° C (unrefined) and 232 ° C (refined). Use for sauces, frying, stewing and deep-frying. See Argentinean meat stew recipe.

Argentinean meat stew cooked with corn oil

Almond oil

Boiling point - 216 °C. Use for baking, frying and making dressings. Watch the video recipe for lean chocolate cookies cooked with almond butter.

Lenten cookies with chocolate on almond butter

Palm oil

Many "horror stories" have been written about it, but we advise you to simply choose it correctly - buy ONLY red palm oil! An infrequent guest on our shelves. It is better to look in stores of organic products. Boiling point - 230 °C. Suitable exclusively for frying and deep-frying.

Read about the benefits and harms of palm oil.

Palm oil

Sunflower oil

The boiling point for refined is 227 ° C, for unrefined - 107 ° C. Sunflower oil direct extraction (unrefined) should never be used for frying. But it is ideal for marinating and salad dressings.

Sunflower oil

Sesame oil

The boiling point for semi-refined sesame oil is 232 °C, for unrefined sesame oil - 175 °C. It adds an Asian flavor to dishes, and is used in dressings, sauces, and as a fragrant addition to other oils in wok dishes. See the recipe for crispy vegetable salad with sesame oil dressing.

Crispy vegetable salad for weight loss

Rapeseed oil

The boiling point of refined oil is 227 °C. but some chefs recommend not heating it above 160-180 ° C., arguing that then it starts to taste bitter. For gas stations it is better to use refined.

Cheesecakes cooked in corn oil

For comparison, butter will start to burn at 150 °C, ghee burns at 250 °C, lard burns at 190 °C.

Today we will talk about carcinogens in fried foods.

Carcinogens- chemicals, the impact of which on the human or animal body increases the likelihood of malignant neoplasms (tumors) or leads to them.

Toxic, carcinogenic and simply harmful substances in oils are formed in two cases:

• When oils are heated to smoke point and higher;
• When oils go rancid.

Smoke point of vegetable fats and oils

"Smoke temperature"- this is the temperature at which the oil begins to smoke in the pan, from that moment it starts reactions to form toxic and carcinogenic substances. Each type of oil has its own smoke point. In general, all oils are divided into oils with high smoke point and with low smoke point.

Oils with a high smoke point are recommended for frying, including deep frying. The refining process raises the smoke point. Oils with a low smoke point are not recommended for frying. I will give the smoke point of some oils.

Oils with a high smoke point:

• Peanut - 230°C
• Grapeseed - 216°C
• Mustard - 254°C
• corn refined- 232°C
• Sesame - 230°C
• olive extra virgin-191°C
• Olive - up to 190°C
• Palm - 232°C
• Sunflower refined- 232°C
• Refined rapeseed - 240°C
• Rice - 220°C
• soybean refined- 232°C
• Hazelnut oil - 221°C

Oils and fats with a low smoke point:

• Walnut oil - 150°C
• Flaxseed - 107°C
• Sunflower unrefined- 107°С
• Pork fat - 180°C
• Creamy - 160°C

Standard electric stoves give a heating temperature usually not more than 300 ° C, gas stoves - much more. There is evidence that cast iron pans can reach up to 600°C on gas stoves! Now it becomes clear why it is so easy to exceed the smoke point of oil.

Toxic substances formed when oils are heated or rancid and ways to avoid their formation

Let's take a closer look at the substances that are formed when oils are heated strongly or rancid.

Acrolein- aldehyde of acrylic acid, belonging to the group of tear poisonous substances. Due to its high reactivity, acrolein is a toxic compound that strongly irritates the mucous membranes of the eyes and respiratory tract. Acrolein is one of the thermal decomposition products of glycerol and glyceride fats. The process of formation of acrolein begins immediately when the oil reaches its smoke point, that is, at the beginning of the burning of the oil. I think everyone's eyes were pinched when the oil was burning, they also say about such cases “there is a bug in the kitchen” - this is acrolein. Therefore, NEVER heat oils to a smoky state!

Acrylamide-acrylic acid amide. Toxic, affects the nervous system, liver and kidneys, irritates mucous membranes. In fried or baked foods, as well as baked goods, acrylamide can form in the reaction between asparagine and sugars (fructose, glucose, etc.) at temperatures above 120°C. Simply put, acrylamide is formed in the fried crust on starchy foods, such as potatoes, donuts, pies, which have been subjected to long-term or high-temperature frying in vegetable oil. Acrylamide is especially active when deep-fried for a long time. Some unscrupulous manufacturers of fried foods, in order to save money, use the same oil several times, continuing to fry more and more portions of products on it. In this case, the poison is formed inevitably. Therefore, I strongly recommend not to fry at high temperatures for a long time and to abandon deep-frying.

Free radicals and fatty acid polymers, as well as heterocyclic amines- are actively formed in the products of smoking and burning. Amines are very toxic substances. Both inhalation of their vapors and skin contact are dangerous.

Polycyclic substances with a high carbon content(coronene, chrysene, benzpyrene, etc.) - are strong chemical carcinogens and are also formed in smoke and burning products. For example, benzpyrene is a Class I chemical carcinogen. It is formed when products are burned: cereals, fats, is found in smoked products, products “with smoke”, is present in smoke, substances obtained by burning resins. EU Commission Regulation No. 1881/2006 of 19.12.06 determines that vegetable oils and fats must contain less than 2 µg of benzpyrene per 1 kg; in smoked products up to 5 mcg/kg; in cereals, including baby food, up to 1 mcg/kg. Attention! In some cases, for example, overcooked meat cooked in a charcoal barbecue can contain up to 62.6 µg/kg of benzpyrene!!!

When rancid oils are formed, mainly aldehydes, epoxides and ketones. By interacting with atmospheric oxygen when exposed to light and heat, the oil changes its taste and smell. For fats in which saturated fatty acids predominate, the formation of ketones (ketone rancidity) is characteristic, for fats with a high content of unsaturated acids - aldehyde rancidity.

Ketones- toxic. They have an irritating and local effect and penetrate the body through the skin. Some substances have a carcinogenic and mutagenic effect.

Aldehydes- toxic. Able to accumulate in the body. In addition to general toxic, they have an irritating and neurotoxic effect. Some are carcinogenic.

Therefore, friends, if it is not possible to completely eliminate fried foods from the diet, please fry correctly, relying on this article and follow the simple tips below:

1. Do not bring the oil to a smoking temperature;
2. Avoid prolonged frying in oil, such as deep frying. If you do fry, do not use one serving of oil several times;
3. Don't overcook food. Remember that burnt foods contain toxic substances and carcinogens;
4. For frying, choose only refined oils and fats with a high smoke point;
5. Store oils according to the instructions on the label and do not eat rancid oils.

More articles on vegetable oils: