Cooking oil is a plant, animal, or synthetic fat used for frying, grilling, and other types of cooking. It is also used in food preparations and flavorings that do not involve heat, such as salad dressings and bread dips, and in this sense may be more aptly called vegetable oils.
Cooking oil is usually liquid at room temperature, although some oils contain saturated fat, such as coconut oil, palm oil, and solid palm kernel oil.
There are a variety of cooking oils from plant sources such as olive oil, palm oil, soybean oil, canola oil (rapeseed oil), corn oil, peanut oil and other vegetable oils, and animal based oils such as butter and lard..
Oil can be flavored with aromatic foods such as herbs, chili or garlic.
Video Cooking oil
Health and nutrition
Guidelines for the right amount of fat - the components of daily food consumption - are set by regulatory bodies such as the Food and Drug Administration. The recommendation is that 10% or fewer daily calories should come from saturated fats, and 20-35% of total daily calories should come from polyunsaturated and monounsaturated fats.
While consumption of a small amount of common saturated fat in the diet, the meta-analysis found a significant correlation between high consumption of saturated fats and blood LDL concentrations, risk factors for cardiovascular disease. Other meta-analyzes based on cohort studies and in randomized controlled trials found positive, or neutral, effects from consuming polyunsaturated fats in lieu of saturated fats (10% lower risk for 5% replacement).
Mayo Clinic has highlighted certain high saturated fatty acids, including coconut, palm oil and palm kernel oil. Those who have lower saturated and higher levels of unsaturated fats (preferably monounsaturated) such as olive oil, peanut oil, canola oil, soybeans and cottonseed oil are generally healthier. The US National Heart, Lung and Blood Institute urges saturated fats to be replaced with polyunsaturated and monounsaturated fats, including olive and canola oils as a healthier source of healthy monounsaturated fats while soybeans and sunflower oils are a good source of polyunsaturated fat. One study showed that the consumption of non-hydrogenated unsaturated oils such as soybeans and sunflowers is preferred over the consumption of palm oil to lower the risk of heart disease.
Peanut oil, cashew nut oil and other peanut-based oils can pose a danger to people with peanut allergies.
Trans fat
Unlike other dietary fats, trans fats are not important, and they do not promote good health. The consumption of trans fats increases a person's risk of developing coronary heart disease by increasing LDL "bad" cholesterol levels and lowering "good" HDL cholesterol levels. Trans fats from partially hydrogenated oils are more harmful than naturally occurring oils.
Several large studies have shown an association between consumption of trans fats and coronary heart disease, and possibly some other diseases. The US Food and Drug Administration (FDA), National Heart, Lung and Blood Institute and the American Heart Association (AHA) all recommend limiting intake of trans fats.
Cooking with oil
Heating oil changes its characteristics. Healthy oil at room temperature can be unhealthy when heated above a certain temperature, so when choosing cooking oil, it is important to match the heat oil tolerance with the temperature to be used. The temperature of the deep frying pan generally ranges from 170-190 ° C (338-374 ° F), much less, lower temperatures> = 130 ° C (266 ° F) are used.
Palm oil contains more saturated fats than canola oil, corn oil, linseed oil, soybean oil, safflower oil, and sunflower oil. Therefore, palm oil can survive deep frying at higher temperatures and is resistant to oxidation compared to polyunsaturated vegetable oils. Since around 1900, palm oil has been increasingly incorporated into food by the global commercial food industry because it remains stable in frying, or in roasting at very high temperatures, and for high levels of natural antioxidants, although refined palm oil used in industrial food has lose most of its carotenoid content (and its orange-red color).
The following oil is suitable for frying high temperatures because its high smoke point is above 230 ° C (446 ° F):
- Avocado oil
- Mustard Oil
- Palm oil
- Peanut oil (marketed as "peanut oil" in the UK and India)
- Rice bran oil
- Safflower oil
- Semi-fine sesame oil
- Semi-soft spring sunflower
A less aggressive frying temperature is often used. Quality cooking oil tastes bland, at least 200 ° C (392 ° F) and 315 ° C (599 ° F) points, with a maximum of 0.1% free fatty acid and 3% linolenic acid. Oils with higher linolenic fractions are avoided because polymerization or gumming is characterized by increased viscosity with age. Olive oil is resistant to thermal degradation and has been used as cooking oil for thousands of years.
- Olive oil
Saving and storing oil
All oils are degraded in response to heat, light, and oxygen. To delay the onset of rancidity, an inert gas blanket, usually nitrogen, is applied to the vapor chamber in the storage container immediately after production - a process called the blanket tank.
In a cool, dry place, oil has better stability, but may thicken, although they will soon return to liquid form if they are left at room temperature. To minimize the effects of lowering heat and light, the oil must be removed from cold storage long enough to be used.
High refined oils of monounsaturated fats, such as macadamia oil, hold up to one year, while high-polyunsaturated fats, such as soybean oil, store for about six months. The rancidity test has shown that the shrimp oil lifespan is about 3 months, the time period is much shorter than the best before indicated on the label.
In contrast, high-saturated fatty acids, such as avocado oil, have a relatively long shelf life and can be stored safely at room temperature, because the low content of polyunsaturated fat facilitates stability.
Maps Cooking oil
Types and characteristics
Cooking oil consists of various fractions of fatty acids. For the purpose of frying foods, high-fat monounsaturated or saturated fats are generally popular, while high-fat polyunsaturated fats are less desirable. High oleic acid oils include almonds, macadamia, olives, hazelnuts, pistachios, and high-oleic safflower and sunflower oleic cultivars.
Smoke point
The smoke point is marked with a "continuous smoke blob." This is the temperature at which oil begins to burn, leading to a burning sensation in the prepared food and nutrient degradation and phytochemical characteristics of the oil.
Above the smoke point is the point of fire and fire. The flash point is the temperature at which the oil vapor will ignite but is not produced in sufficient quantities to remain lit. Flash point generally occurs at about 275-330 Â ° C (527-626 Â ° F). The fire point is the temperature at which the hot oil produces enough steam to burn and burn. As the cooking hour increases, all these temperature points decrease. They are more dependent on the acidity of the oil than the fatty acid profiles.
The smoke points of cooking oil vary widely in relation to how the oil is distilled: higher smoke points result from the removal of impurities and free fatty acids. The remaining residual solvent from the purification process can decrease the smoke point. It has been reported to increase with the inclusion of antioxidants (BHA, BHT, and TBHQ). For this reason, published oil fumes may vary.
The oil is extracted from nuts, seeds, olives, grains or legumes by extraction using industrial chemicals or by mechanical processes. Expeller pressing is a chemical-free process that collects oil from a source using a mechanical press with minimal heat. Cold pressed oils extracted under controlled temperature settings usually below 105 ° C (221 ° F) are intended to preserve natural phytochemicals, such as polyphenols, sterols and vitamin E that collectively affect color, aroma, odor and nutritional value..
Extraction and distillation of cooking oil
Extraction and distillation of cooking oil is a separate process. The first extraction removes oil, usually from seeds, nuts or fruit. Improvements then change the appearance, texture, taste, smell, or stability of oil to meet buyer expectations.
Extraction
There are three broad types of oil extraction:
- Chemical solvent extraction, most often using hexane.
- Press, using expeller press or cold press (pressing at low temperature to prevent oil heating).
- Decanter centrifuge.
In large scale industrial oil extraction you will often see some combination of presses, chemical extraction and/or centrifugation to extract the maximum amount of oil possible.
Refinement
Cooking oil can be purified, or refined using one or more of the following narrowing processes (in any combination):
- Distillation, which heats the oil to evaporate the chemical solvent from the extraction process.
- Degumming, by passing hot water through oil to precipitate sap and water-soluble proteins but not in oil, then dispose of water along with dirt.
- Neutralization, or deacidification, which treats oil with sodium hydroxide or sodium carbonate to remove free fatty acids, phospholipids, pigments, and waxes.
- Bleaching, which removes the "off-color" component by treatment with soil, activated carbon, or active clay, followed by heating, filtering, then drying to recover oil. Dewaxing, or winterizing, improves the clarity of oil intended for cooling by dropping it to low temperatures and removing any formed solids.
- Eliminates odors, by treating with high-pressure steam to evaporate unstable compounds that may cause "unusual" odors or flavors.
- The addition of preservatives, such as BHA and BHT to help preserve oils that have been made less stable due to high temperature processing.
Screening, a non-chemical process that filters out larger particles, can be regarded as a refinement step, although it does not change the state of oil.
Most commercial large-scale cooking oil improvements will involve all of these steps to achieve a uniform product in taste, smell and appearance, and have a longer shelf life. Cooking oil devoted to the health food market will often be unrefined, which can produce less stable products but minimize exposure to high temperatures and chemical processing.
Cooking oil waste
The proper disposal of used cooking oil is an important waste management issue. Oil can clot in the pipes provoking blockages.
Therefore, cooking oil should not be thrown in the kitchen sink or in the toilet. The right way to dispose of oil is to put it in a recyclable container and dispose of it with ordinary trash. Placing oil containers in the fridge to harden also makes disposal easier and less messy.
Recycling
Cooking oil can be recycled. It can be used as animal feed, directly as fuel, and to produce biodiesel, soap, and other industrial products.
In the recycling industry, used cooking oil taken from restaurants and food processing industries (usually from deep fryers or griddles) is called recycled vegetable oil (RVO), vegetable oils used (UVO), vegetable oil waste (WVO), or < b> Fat yellow .
Yellow fats are used to feed livestock, and to make soap, makeup, clothing, rubber, detergents, and biodiesel fuel.
Used cooking oil, other than converted to biodiesel, can be used directly in modified diesel engines and for heating.
Grease traps or interceptors collect fats and oil from kitchen sinks and floor drains that will become clogged drains and disrupt septic systems and waste treatment. The collected product is called brown grease in the recycling industry. Brown grease is contaminated with rotting food solids and is considered unsuitable for reuse in most applications.
Forgery
Gutter oil and gutter oil are terms used in China to describe recycled oils processed to resemble virgin oil, but contain toxic contaminants and are sold illegally for cooking; the origin is brown oil from waste.
In Kenya, thieves sell transformer oil stolen from electrical transformers to roadside stalls operators for frying use, suitable for long-term use longer than ordinary cooking oils, but a threat to consumer health due to the presence of PCBs.
Note
References
Source of the article : Wikipedia
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