Healthy cooking quiz: How sharp are your skills?

Though it's true that salt can slightly increase the boiling temperature of water, it doesn't affect the time it takes to cook food. So skip the salt when making pasta, rice, vegetables, legumes and other foods you boil.

Another reason to pass on the salt: It toughens many vegetables and legumes because it draws the water out of plant cells. Salt also increases the amount of sodium in your food. Use herbs and spices instead for your seasoning.

For a final burst of flavor and color, add fresh herbs toward the end of cooking. Herbs — the aromatic leaves of plants — enhance flavor without fat or salt.

When substituting dried herbs for fresh herbs, use about one-third the amount. Add dried herbs in the earlier stages of cooking. Dried herbs lose their flavor over time, so buy only what you'll use in a few months.

Two egg whites — or a quarter cup of egg substitute — are effective replacements for one whole egg. This reduces the amount of fat and cholesterol in your recipe, without affecting taste or texture.

You can usually substitute oil for butter or shortening in breads (yeast and quick breads) without significantly affecting the quality of the final product. This isn't the case with other baked goods such as pastries, cakes and cookies, however. To avoid dense, soggy or flat baked goods, don't substitute fat-free or low-fat margarine for regular margarine. Also, most fat-free products, such as fat-free sour cream or cream cheese, contain large amounts of water. Using these products could leave your baked goods flat or soggy.

In most baked goods, you can leave out half the amount of sugar in a recipe without it affecting texture or taste. But because sugar increases moisture in baked goods, make sure you use at least 1/4 cup of sugar, honey or molasses for every cup of flour. Leaving out 1 cup of sugar cuts about 775 calories from the entire recipe.

Olive oil is best suited for salad dressings, marinades and sauces because of its deep, rich flavor. Olive oil can be used for sauteing if you use moderate temperatures. Most types of olive oil aren't suited for cooking at high temperatures — such as in stir-frying — because they have a low smoke point. The smoke point is the point at which, when heated, the oil begins to smoke, smell bitter and give an unpleasant flavor to food. The higher the smoke point, the more suitable the oil is for cooking at high temperatures. Canola oil, peanut oil and safflower oil, which have high smoke points, are better choices for stir-frying.

Eggplant, peaches, tomatoes and peppers all cook well on the grill. In fact, you can grill most fruits and vegetables, including summer squash, sweet onions, mushrooms, broccoli, mangoes, pineapples and pears. The key for grilling fruits and vegetables is to use low heat. Coals are ready when you can hold your hand safely about 5 inches above the heat for about five seconds.

Thirty-five percent of the alcohol remains in food after stirring it in and baking the food for 30 minutes. Because alcohol boils at a low temperature, much, but not all of the alcohol, evaporates after being cooked. The total amount of alcohol remaining depends on the preparation method and the length of cooking. For instance, cooking food longer typically reduces alcohol content further. Because alcohol isn't used in high concentrations in most recipes, the amount remaining shouldn't pose any health concerns.

False. Doubling a recipe — doubling the number of servings from two to four, for instance — isn't as simple as it sounds. Though some recipes lend themselves to simply doubling all ingredients, others don't. Casseroles, stews and other main dishes are usually OK to double. However, baked goods — especially those that include leavening agents, such as baking powder, baking soda or yeast — may not turn out well if doubled.