Choosing a Good Vegetable Oil

High-quality vegetable oils are the best way to meet your body’s daily requirement for fat and fulfill many of the body’s nutritional requirements. Natural vegetable oils carry nutrients that are essential to good health. Read about oils necessary to your health, and learn about processing methods that affect oil quality. By keeping in mind a few key points about oils, fat content, processing methods, and best uses in the kitchen, you’ll be able to purchase the healthiest products for your needs.

Necessary Nutrients and Disease Fighters in Vegetable Oils

Though excess consumption of saturated fat, and the cholesterol found in animal fats, has been associated with heart and arterial disease, some fat is necessary in a daily diet to ensure good health. Current studies suggest that an ideal diet might provide 25 percent of calories from oils and fat.

Fat is needed by the body for absorption of the fat-soluble vitamins, A, D and E. Vegetable oils are one of the few sources of the essential fatty acids (EFA) linoleic and linolenic acid. Vegetables oils, especially wheat germ oil, are good sources of vitamin E.

Some oils also contain Omega-3 fatty acids which have been shown to protect the body from heart disease and some types of cancer. Flax seed, canola, walnut, and soy oils are good sources of Omega-3 fatty acids.

Monounsaturated oils, like olive, peanut, canola, and high-oleic oils also protect the body from heart disease by raising the blood level of HDL, the good cholesterol. Higher levels of HDL prevent plaque build-up on arterial walls. Consumption of polyunsaturated oils, like safflower, and soybean oils lowers levels of the bad cholesterol, LDL but also of the good, HDL.

Types of Oil

Oils are classified as either saturated, monounsaturated or polyunsaturated. Saturation refers to the carbon-hydrogen makeup of the oil. The more hydrogen, the greater degree of saturation and solidity of the oil.

Polyunsaturates

Polyunsaturated fats such as safflower oil never solidify, even when refrigerated.

Monounsaturates

Monounsaturated fats such as olive oil, are generally liquid at room temperature and either semi-congealed or solid when refrigerated.

Saturates

Saturated fats such as coconut oil, butter and lard, are solid at room temperature.

Oil Processing

Several different steps and methods are used in the processing of oils. The quality, flavor and nutritional content of oils vary greatly according to which processes are used.

Extraction

How an oil is extracted affects the nutritional quality of the oil because heat, light and oxygen can destroy nutrients. Here are the most commonly used extraction methods:

Expeller pressing—a process that uses mechanical pressure rather than chemicals to extract oil from its source. Friction generates temperatures that may be as high as 185 degrees Fahrenheit depending on the hardness of the seed, grain, bean or nut.

Cold pressing—term sometimes used for expeller pressing at temperatures below 120 degrees Fahrenheit. The only true cold pressed oil is extra virgin olive oil, the first pressing of olives.

Vacuum extraction—recently developed vacuum (SpectraVac) expeller process system that extracts oils in a non-oxygen and light-free atmosphere at temperatures as low as 70 degrees Fahrenheit.

Solvent extraction—oils are extracted chemically with petroleum solvents which destroy the oil’s nutritional value.

Refining

The highest quality oils with the most nutritional value are unrefined. Unrefined oils also retain their full flavor, whereas refined oils are virtually odorless and tasteless. During refining, oils are first degummed, a process which removes the beneficial compound lecithin. Then oils are treated with chemicals at high temperatures to bleach and deodorize. Finally, some oils also have added preservatives.

Hydrogenation

Hydrogenation is the chemical process that transforms a liquid oil into a solid or partially solid form. The process uses heavy metals, hydrogen gas and extremely high temperatures. Hydrogenation destroys nutrients and transforms the fat into
trans-fatty acids. Consuming trans-fatty acids has been linked to high cholesterol and heart disease.

Margarine and shortening are products that have been hydrogenated. Other sources of hydrogenated or partially hydrogenated oils are packaged snacks like cookies, crackers, chips and pastries. Look for brands of these snacks that use natural vegetable oils to give you a healthier choice.

Storage Tips

The packaging and storage of oils can affect their quality. Heat, oxygen and light promote rancidity. Unrefined oils should be stored in cool, dark places and unrefined oils that are high in Omega-3 fatty acids should be stored in the refrigerator. Natural or unrefined oils will keep from four to six months if stored properly. Refined or heavily processed oils will keep twice as long.

Many supplement oils are sensitive to heat and light. Keep refrigerated in a dark container. Supplement oils are not for cooking, but can be added to prepared foods.

Vegetable Oils for Cooking

Avocado For sautéing and salads.

Canola High in Omega-3. Monounsaturated. Mild flavor. Great for cooking, baking, light sautéing and salads.

Coconut Saturated fat 92 percent.

Corn Good for baking and in salads.

Grape Seed High in linoleic acid and low in saturated fats. It has a light, nutty taste, good for cooking.

Palm Kernel Saturated fat 83 percent. Used commercially to prevent candy coatings from melting.

Peanut Monounsaturated. Great for frying, baking and in salads.

Olive Monounsaturated. For salads and light sautéing.

Safflower Great as a salad oil, for cooking, or baking. Available in regular and high-oleic forms.

Sesame Excellent for stir frying and deep frying. Toasted sesame oil is a highly concentrated and aromatic oil added to stir fry or cooked dishes.

Soybean Contains Omega-3. Has a strong flavor. Can be used in cooking, baking and salads.

Sunflower Mild flavor. Good for most uses except deep frying. Available in regular and high-oleic forms.

Walnut Gourmet cooking oil. Great in salad dressings. Contains Omega-3.

Supplement and Body Oils

Apricot Use as a body oil.

Almond Use as a body oil.

Borage Comes from the seed of the flowering herb borage. It is an important source of gamma-linoleic acid (GLA).

Cod Liver A good source of vitamin A and D and essential fatty acids.

Evening Primrose Extracted from primrose seeds, this oil is a good source for essential fatty acids (EFAs).

Flax Seed Supplement oil highest in Omega-3. Buttery flavor. Great in salad dressings, on steamed vegetables and baked potatoes. Also known as linseed oil.

Fish Often derived from salmon, menhaden, cod and mackerel, these oils are a good source of omega-3 and omega-6 essential fatty acids.

Hemp Rich in essential fatty acids (EFAs), hemp oil has a pleasant nutty flavor, and can be used internally or applied topically. It is not known whether commercially prepared hemp oil will result in failed drug screening tests.

Wheat Germ An excellent source of vitamin E and rich in naturally occurring antioxidants.

Definitions

Essential fatty acids (EFAs) are critical to our health, but our bodies do not manufacture them. They must come from our diet.

Gamma-linoleic acid (GLA) is an essential fatty acid needed for growth and repair of cells.

Omega-3 and Omega-6 are beneficial fatty acids that fight heart disease and cancer.

I found this excellent information while shopping in the Moscow Idaho Food Co-op — an amazing place full of great food and people.

© Twin Cities Natural Food Co-ops.