While cooking oils are pure fat, they are not created equal. All cooking oils are a combination of saturated, polyunsaturated and monounsaturated fats. It is the concentration of hydrogen that determines how they are categorized. Without getting too technical, the following information will hopefully provide a basic understanding of fats.
Saturated fats are found in animal products and are converted into cholesterol by the liver. Butter, margarine, meats and dairy products are especially high in saturated fat. Saturated fat will elevate blood cholesterol levels and is associated with increased rates of heart disease and stroke. It is solid at room temperature.
There are two types of unsaturated fats: monounsaturated and polyunsaturated. Monounsaturated and polyunsaturated fats do not raise blood cholesterol levels. Canola and olive oils contain the highest proportion of monounsaturated fat when compared with other cooking oils. Safflower and corn oil are the highest in polyunsaturated fats.
Trans fats are man-made or processed fats, which are made from a liquid oil. When hydrogen is added to liquid vegetable oil and pressure is added, the result is a stiffer fat, like the fat found in a can of Crisco. Trans fats are also called hydrogenated fats and are found in margarine and trans fat partially hydrogenated vegetable oils. Trans fats pose a greater risk of heart disease than saturated fats (which were once believed to be the worst kind of fats). While it is true that saturated fats (found in butter, cheese, beef, coconut and palm oil) raise total cholesterol levels, trans fats not only raise total cholesterol levels, they also deplete good cholesterol (HDL), which helps protect against heart disease.
Partially Hydrogenated Fats:
If you have health concerns, read food labels to see if they list “partially hydrogenated oil” as an ingredient. Partially hydrogenated oils are present in all commercially made donuts, crackers, cookies, pastries, deep-fat fried foods (including those from all major fast-food chains), potato and corn chips, imitation cheeses, and confectionery fats found in frosting and candies. All of these products contain unsaturated fats which can be damaged at high temperatures and converted to a trans fat.
Understanding the Difference between Refined and Unrefined Cooking Oils…
Refined oils are extracted by solvent extraction for further refining in order to produce clear oil that is free from rancidity and foreign matter. These oils are used as medium cooking oils (225°F to 350°F), high cooking oils (350°F to 450°F) and deep frying oils (greater than 450°F). Refined oils are bland and pale. They have negligible flavor and aroma which makes them ideal for preparing delicately flavored dishes. Use for baking, sauteing, stir-fry and wok cooking, baking, searing, browning, deep-frying and pan-frying.
Unrefined oils are processed by cold-pressed and expeller-pressed methods. They carry the true flavor of the plant from which the oil is made. The strong flavor of unrefined oils may overwhelm the dish or baked good that is prepared with them; however, strong flavor is not always undesirable and some unrefined oils are used as flavoring agents. (Generally, when there is a strong natural flavor and aroma, there is a higher amount of nutritional value.) These oils are typically called salad oils and are used for salad dressings, marinades, sauces and as light cooking oils for light sautes and low heat baking. As a general rule, they should not be cooked at high temperatures. (The one exception is unrefined safflower oil which is capable of reaching a temperature necessary for deep-frying.) Unrefined oils should not be used at temperatures above 320°F.
Various Cooking Oils and Recommended Use…
Some oils have low smoke points, which means that they will burn at low temperatures. These oils, typically called salad oils, are best used for salad dressings, marinades, sauces and as light cooking oils for light sautes and low heat baking. Other cooking oils have a high smoke point, which means that they can reach higher temperatures without smoking. These particular oils are ideal for deep-frying, pan-frying and sauteing. The information below will discuss various types of cooking oils and their recommended use.
- Canola – Canola oil is a monounsaturated oil extracted from the seeds of a plant in the mustard family. It has a mild flavor and aroma and is most commonly available in a refined form. It has a bland flavor and is recommended for deep-frying, pan-frying, sauteing, baking and preparing salad dressings. Its mild flavor and relatively high smoke point (400°F) make refined canola oil a good all-purpose oil. Of all the cooking oils, canola has the least amount of saturated fat (6%) and is the least expensive.
- Corn – Made from the germ of the corn kernel, corn oil is almost tasteless and is high in polyunsaturated fat (62%). It is used to make margarine, salad dressings and mayonnaise. With a smoke point of 450°F, it is excellent for pan-frying and deep-frying because it can withstand high temperatures without smoking.
- Olive – Olive oil is a monounsaturated oil extracted from tree-ripened olives. The color may range from light amber to green with flavors that range from bland to extremely strong. Olive oil is graded according to its degree of acidity and the process used to extract the oil. Oil labeled “virgin” is cold pressed (a process using no heat or chemicals) and contains low levels of acidity. It provides the body with vitamins E and F. Oil labeled “pure” uses heat and chemicals to process olive residue from subsequent pressings. Unrefined olive oil has a smoke point of 320°F and is recommended for baking, sauteing, stir-frying and wok cooking.
- Peanut – Made from pressed, steam-cooked peanuts, peanut oil contains 18% saturated fat. It has a bland flavor and is good for cooking because it doesn’t absorb or transfer flavors. Frying with peanut oil gives foods a rich, nutty, roasted flavor. Refined peanut oil has a smoke point of 450°F and is recommended for stir-frying, wok cooking, pan-frying and deep-frying.
- Safflower – Made from safflower seeds, safflower oil is pale yellow and almost flavorless. It has more polyunsaturated fat that other oils (78%) but lacks vitamin E. It is considered a good, all-purpose cooking oil. Safflower oil is a favorite for salads because it does not solidify when chilled. Refined safflower oil has a smoke point of 450°F and is recommended for deep-frying, pan-frying, sauteing and baking.
- Sesame – Made from pressed sesame seeds, sesame oil is high in polyunsaturated fat (43%) and monounsaturated fat (42%). It comes in two varieties, light and dark. Light sesame oil is made with untoasted sesame seeds and has a nutty flavor. It is especially good for stir-frying, wok cooking and preparing dressings. Dark sesame oil (Asian) is made with toasted sesame seeds and has a much stronger flavor than light sesame oil. It should only be used in small quantities for flavoring foods; it is not suitable for cooking. Refined sesame oil has a smoke point of 350°F and semirefined sesame oil has a smoke point of 450°F.
- Soybean – Highly refined soybean oil is reasonably priced, very mild, versatile and it represents approximately 80% of all the cooking oils used in commercial food production in the USA. Almost any product that lists vegetable oil as an ingredient most likely contains refined soybean oil. With a smoke point of 450°F, soybean oil is a good, all-purpose oil. Use for deep-frying, pan-frying, wok cooking, stir-frying and baking.
- Sunflower – Made from sunflower seeds, sunflower oil is pale yellow in color, has a bland flavor and is considered a good, all-purpose oil. It is low in saturated fat and high in polyunsaturated fat. Semirefined sunflower oil has a smoke point of 450°F and is excellent for sauteing, preparing salad dressings, deep-frying and pan-frying.
- Vegetable – Vegetable oil is an inexpensive, all-purpose oil which is a blend of refined oils made from vegetables, nuts and seeds. Most vegetable oils are made from soybeans and are high in monounsaturated fat, high in polyunsaturated fat and low in saturated fat. Designed to have a mild flavor and a high smoke point, it is recommended for deep-frying, pan-frying, sauteing and baking.Note: The American Heart Association Cookbook, Fifth Edition, recommends all of the above cooking oils with the exception of peanut oil due to its high saturated fat content.
Miscellaneous Facts, Tips and Warnings…
- Essential fatty acids are vital for good health. Without some fats in our diets, we cannot absorb the fat-soluble vitamins A, D, E and K.
- All cooking oils contain 100% fat.
- A tablespoon of cooking oil contains 14 grams of fat.
- All cooking oils contain the same number of calories – one tablespoon contains 120 calories.
- For better health, choose oils/fats that are low in saturated fat.
- Cooking oil used for deep-frying can usually be reused several times. Wait until the oil has cooled completely before handling then strain it into a clean sealable container for storing.
- The most accurate method of testing the temperature of oil for deep-frying is a deep-fat thermometer. Make sure the bulb of your thermometer is completely immersed in the oil, but not touching the bottom of the pan. Otherwise, the reading could be affected. If a deep-fat thermometer is not available, the age-old method of dropping a square of bread into the hot oil will suffice. If the bread cube rises to the surface crackling and frying, the oil’s hot enough.Rule of thumb when using this method – If the bread cube browns uniformly in:
60 seconds, the temperature is 350-365°F40 seconds, the temperature is about 365-382°F
20 seconds, the temperature is about 382-390°F
- To dispose of used cooking oil, carefully pour cooled oil into a strong sealable container, such as an old plastic jar with a lid or old coffee can. (Avoid using breakable glass jars.) If the amount of oil is small, place the filled, sealed jar in the trash. Dispose of large amounts of cooking oil by taking it to the local landfill.
- Do not pour cooking oil down the kitchen drain. Even small amounts will eventually clog the plumbing.
- Remember to always wait until cooking oil has cooled completely before handling.