Cookbook:Oil and Fat
Cookbook | Recipes | Ingredients | Basic foodstuffs | Nutrition
Oils and fats, also called lipids, are one of the three basic types of calorie sources, the others being carbohydrates and proteins. With 9 calories per gram (38 kJ/g), lipids have the highest food energy content of the three. The other two have 4 calories per gram.
In general, the difference between oils and fats is that, at normal room temperature, fats are solid while oils are liquid. Palm, palm kernel, and coconut oils are exceptions to this rule.
Role in human healthEdit
Many lipids are absolutely essential for life, and a minimum amount of dietary fat is necessary to facilitate absorption of fat-soluble vitamins (A, D, E and K) and carotenoids. However, certain lipids, particularly trans-fatty acids are risk factors for heart disease, among others, and some individuals may wish to limit them in their diet.
Humans have a dietary requirement for certain essential fatty acids, such as linoleic acid (an omega-6 fatty acid) and alpha-linolenic acid (an omega-3 fatty acid) because these fats cannot be synthesized from simpler components in the diet. Most vegetable oils (including safflower, sunflower, and corn oils) are rich in linoleic acid. Alpha-linolenic acid is found in the green leaves of plants, and in selected seeds, nuts and legumes (such as flax, canola, walnuts and soy). Fish oils are particularly rich in the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
The foods listed below each type of lipid contain high concentrations of that lipid.
- Butter, ghee, suet, tallow, coconut oil, and palm kernel oil, dairy products (especially cream and cheese), solid fat on meat, chocolate, and some prepared foods.
- Nuts, avocados, tea seed oil, olive oil, grapeseed oil, ground nut oil, peanut oil, flaxseed oil, sesame oil, corn oil, popcorn, whole grain wheat, cereal, oatmeal, safflower oil, sunflower oil, tea-oil Camellia. Canola oil is 57%–60% monounsaturated fat, olive oil is about 75% monounsaturated fat, lard is 45% monounsaturated fat, while tea seed oil is commonly over 80% monounsaturated fat. Other sources include
- Grain products, seafood (herring, salmon, mackerel, halibut, fish oil), soybeans, sunflower oil, safflower oil, cottonseed oil, flaxseed oil. Foods like mayonnaise and soft margarine may also be good sources, but nutritional facts vary by style and brand.
- Trans unsaturated
- Trans fats make up 2–5% of the total fat in the milk and body of ruminants (such as cattle and sheep), however the vast majority of trans fats consumed today are created by the processed food industry. As such, these fats can be found in many fast foods, snack foods, fried foods and baked goods that have hydrogenated oils. Margarine and shortening may also contain high levels of trans fats, depending on their country of origin — for example, Australian margarine is produced by a different method to American margarine and contains no trans fat.
The smoke point of an oil or fat is the temperature at which it gives off smoke. When oil is smoking, it gives off bad fumes and is prone to bursting into flame. Flames from a pot of burning oil will reach up for 2 or 3 feet. The smoke point of an oil should be high when the oil is used for deep-fat frying or when it will be exposed alone on surfaces such as cookie sheets. The numbers here are common values; oils will vary.
Olive oil is particularly variable; higher quality cold-pressed grades have lower smoke points than cheaper solvent-extracted and refined grades. It is better not to use high-quality olive oil for deep frying—save it for your salads.
|Type of oil||Smoke Point|
|Hemp seed oil||170||330|
|Palm kernel oil||?||?|
For a complete list, see Category:Fats and oils or browse below:
- For more in-depth discussion about fats and oils, see the module Biochemistry/Lipids in the Biochemistry textbook.