HEALTHY CORNER

SO MANY OILS, SO LITTLE TIME

Not all oils are created equal. In fact, no one oil can be used for all things; instead, each has its distinct place in the kitchen. Keep these basic categories in mind when you're cooking:

For baking: Coconut, palm, canola and high oleic safflower and sunflower oil work best.

For frying: Because they stand up well to the heat, avocado, peanut, palm and sesame oil are ideal for frying.

For sautéing: Many oils are great for sautéing, including avocado, canola, coconut, grapeseed, olive, sesame and high oleic safflower and sunflower oils.

For dipping, dressings and marinades: When it comes to making dressings and marinades, or finding oil that's perfect to serve alongside crusty bread for dipping, you're looking for terrific flavor. For this purpose look to flax, olive, peanut, toasted sesame or walnut oil.

HOW TO: STORING AND HEATING OIL

Q: Where should I store oil in my kitchen?
A: Unfortunately, oils aren't like wine; they don't improve with age. Heat and light can damage oils, particularly polyunsaturated ones, so keep them in the refrigerator to avoid rancidity. For the record, you'll know your oil is rancid if it takes on a characteristic bad taste and smell, in which case you should toss it and buy fresh oil.

Q: Why does my olive oil get cloudy when it's cold?
A: Some oils, olive oil among them, become cloudy or solidified when refrigerated. Not to worry; it doesn't affect their quality at all. A few minutes at room temperature and things will be back to normal.

Q: I hear people refer to a "smoke point" when they talk about cooking with oil. What's that?
A: Heating oils beyond their smoke point — the temperature at which the oil begins to smoke, generating toxic fumes and harmful free radicals — is never a good idea. Always discard oil that's reached its smoke point, along with any food with which it had contact. Unsure of an oil's smoke point? Most labels on bottles of oil will give you the correct temperature.

TO REFINE OR NOT TO REFINE?

Some oils are refined to make them more stable and suitable for high temperature cooking. Keep in mind, though, that the process removes most of the flavor, color and nutrients from the oils, too. That's why refined oils are perfect for baking and stir-frying, where their high smoke point and neutral flavors are a plus.

On the other hand, unrefined oil is simply pressed and bottled so it retains its original nutrient content, flavor and color. Unrefined oils add full-bodied flavor to dishes and are best used for low- or no-heat applications. (Want to taste the difference? Make this Shiitake Lemongrass Miso Soup.

OIL'S WELL THAT ENDS WELL

If you've ever been called a "fat head," we think we can help. Did you know that your brain is made up mostly of fats, and that fats — including saturated fat — make up the cell membranes that protect the integrity of your cells and their structure?

Fats and oils also play crucial roles in stabilizing blood sugar levels, providing raw materials for making hormones and contributing to a healthy immune system. Think of oils as your body's humanitarians; there's really no end to the good they can do. But remember what your grandfather used to tell you, too: everything in moderation. Since all fats are calorie-rich, remember not to overindulge.

THE FACTS ON FATS

Fats have had a bad reputation in the past, but people are starting to realize that we need them to stay healthy. Fats are one of the three major nutrients of the human diet. The other two are carbohydrates and protein.

So fats are here to stay, and that's a good thing because fats also make a large contribution to the taste, aroma and texture of food — those things that give us such satisfaction when dining.

Before we get down to the details on fats and how they work in the body, you should realize that fats and oils are one and the same. The only difference is that oils are liquid at room temperature and fats are solid. Now, let's move on to the nitty-gritty.

Triglycerides

Simply stated, triglycerides are the chemical form of fats in food and in the body. Think of fats as a building and triglycerides as the bricks that give it shape. Every triglyceride "brick" consists of a mixture of three fatty acids — saturated, monounsaturated and polyunsaturated (the "tri"), and one glycerol molecule. Thus, the name "tri"-"glyceride."

A particular fat is defined by the combination of fatty acids that make up its "bricks." The triglyceride bricks in olive oil, for example, have many more monounsaturated fatty acids than it does saturated or polyunsaturated fatty acids, making olive oil a monounsaturated fat.

Monounsaturated

Monounsaturated fats are heart-healthy because they maintain good HDL cholesterol levels while lowering bad LDL cholesterol levels. They are more chemically stable than polyunsaturated fat but not as stable as saturated fat. This means they keep better than polyunsaturated oils but not as well as saturated oils. They are most appropriate for light cooking or used raw in salad dressings and the like. Oils that are predominantly monounsaturated include olive, avocado, peanut, sesame, lard and duck fat. When stored at room temperature, monounsaturated fats are typically liquid, but they are likely to solidify when stored in the refrigerator.

Monounsaturated oils are generally considered to be the healthiest overall, but it's important to note that all three types have distinct advantages and disadvantages — not just for health but for flavor and culinary characteristics as well. Olive oil seems to have been anointed the "perfect oil" by some in the media, and while it is quite versatile, it cannot be all things to all cooks.

Polyunsaturated

Due to their unstable chemical structure, polyunsaturated fatty acids are more susceptible to rancidity than saturated and monounsaturated fatty acids, especially after prolonged contact with oxygen, light or heat. Oils that are predominately polyunsaturated include walnut, grapeseed, soy, corn and fish oils. These are liquid at room temperature.

Many experts don't recommend polyunsaturated oils for cooking because they are so easily damaged by heat. They are best used in their raw form, and used quickly at that. Never keep polyunsaturated oils beyond their expiration date. If cooking is necessary, use low temperatures. Polyunsaturated oils should be stored refrigerated in dark bottles.

Saturated

Saturated fats are the most chemically stable, giving them a long shelf life and the ability to withstand high cooking temperatures. Typically solid at room temperature, saturated fats are found primarily in animal fats and tropical oils.

Animal Fats

In general, animal fats such as butter, cream and tallow are predominantly saturated, however, two of the most highly saturated fats — coconut oil and palm kernel oil — come from vegetable sources. Furthermore, animal fats like lard, chicken fat and duck fat are predominantly monounsaturated, while fish oils are predominantly polyunsaturated. And it is interesting to note that the fatty acid composition of animal fat can vary depending on the diet of the animal.

Animal fats have their place in the kitchen. Many believe that lard makes the best pie crust, and several traditional Hispanic dishes rely on lard for their distinctive flavor. Butter is the most common animal fat in the kitchen and good quality butters abound, as do cream and other dairy-based products used in cooking. Some producers are now creating high quality lard as well.

Trans Fats: The Very Worst Kind

Trans fatty acids are chemically altered, man-made fats found in partially hydrogenated oils. The hydrogenation process, in common use since the early 20th century, injects hydrogen into vegetable fats under high heat and pressure. This saturates what was previously an unsaturated fat and results in a chemical configuration that is not found in nature and is very rich in trans fatty acids. This is done to make vegetable oils, which are normally liquid at room temperature, solid and more chemically stable, thereby extending the shelf life of products in which they are used. Very small amounts of trans fats do occur naturally in some products such as milk, cheese, beef or lamb.

Trans fats are doubly harmful because they lower HDL (good) cholesterol and raise LDL (bad) cholesterol levels, increasing the risk of coronary heart disease. In fact, trans fatty acids have an even worse impact on cholesterol levels than diets high in butter, which contain saturated fat. A 2002 report by the Institute of Medicine (a branch of the National Academy of Sciences) concluded that trans fats are not safe to consume in any amount. An easy way to avoid trans fats is to shop at Whole Foods Market — we stopped selling products that contain trans fats in 2003.

The Trans Fat Labeling Law

Effective since January 1, 2006, all products that have a Nutrition Facts Panel must declare the amount of trans fat per serving. This has forced many conventional food manufacturers to reduce or eliminate trans fats from their products. But trans fat still has a significant presence in restaurants and with other food vendors who are not affected by the labeling law.

Packaged products from sources other than Whole Foods Market stores may still contain significant amounts of trans fats include: margarine, shortening, baked goods (pastries, pies, cookies, doughnuts), breakfast cereals, fried foods, crackers and snack foods such as potato chips.