Oils derived from plant and seed sources share some basic qualities but there are exceptions. Once you become familiar with the different oils, their qualites and uses, you're well on your way to choosing the right oil for your kitchen.

Plant, nut and seed-derived oils contain no cholesterol, but do contain saturated fat in differing amounts, and that explains why some some oils are more saturated than others. Oils derived from palm, palm kernel, and coconut, also known as the tropical oils, are extremely saturated--even more so than butter or lard! Coconut oil has 92% saturated fat, palm oil tallies in 82% saturated fat, and palm kernel oil is 50% saturated. These oils are not often used for home cooking (except in tropical cuisines and for deep-frying) but are often used in the processed food industry because of their stability (which translates into extended shelf life).

Profiles on the different mono and polyunsaturated oils:

The monounsaturates

Because they are more stable, these oils are safe to be heated, although not for deep-frying over 320F (160C).

• Canola oil

  This is currently a favorite all-purpose oil. It has the least saturated fat of all other oils and a high level of monounsaturated fat. It's a rich source of vitamin E (an antioxidant), has a long shelf life, and remains free-flowing when stored in the refrigerator. It has a high smoke point and has a mild, unobtrusive flavor.

  Note:The source of canola oil is rapeseed, a seed plant usually subjected to heavy pesticides during growing and to solvents during processing. To reap the benefits without ingesting dangerous petro-chemicals, seek out cold-pressed, organic canola oil.

  Fat profile: 22% polyunsaturated; 61% monounsaturated fat; 7% saturated.

• Olive oil

  Perhaps the only oil currently considered a health food. Different grades lend themselves to different uses: use extra virgin as a seasoning in raw or already-cooked dishes--heating it destroys its subtle flavors; use virgin for a more mild flavor in some salads, sautes, or savory baking. (Use olive oil in desserts at your own risk!) Extra virgin oil is always more expensive--but there are some good buys out there from lesser known sources.

  The benefits of using olive oil are numerous and well documented. Historically, it's been a staple food in an area of the world with a very healthy population. The Harvard School of Public Health studied a group of women who consumed olive oil more than once a day, and the results suggested a reduction in breast cancer risk by 25%. Olive oil contains vitamins A, D and E, and also may be helpful in reducing the chances of ulcers and other gastrointestinal ailments.

  Fat profile: 10% polyunsaturated; 75% monounsaturated; 15% saturated.

• Peanut oil

  A deeper-colored oil, usually heat-pressed from peanuts, with a high smoke point. Peanut oil is monounsaturated, with a flavor that ranges from mild to nutty.

  Two points of caution:

  1. A mold known as Aspergillus flavis commonly grows on peanuts, which produces a cancer-causing agent called aflatoxin. If you want to use peanut oil but not the mold, consider choosing an organic brand--organically grown peanut plants are healthier and more resistant to Aspergillus.

  2. Some people have severe allergic reactions to peanut oil or oils derived from other nuts. Give sensitive individuals a small amount to see if they can tolerate it.

  Fat profile: 33% polyunsaturated; 48% monounsaturated; 19% saturated.