3.10: Vegetable Nutrition, Storage and Preparation

Nutrition

Most vegetables are more than 80 percent water; the remaining portions consist of carbohydrates (primarily starches) and small amounts of protein and fat. The relative lack of protein and fat makes most vegetables especially low in calories.

Much of a vegetable's physical structure is provided by generally indigestible substances such as cellulose and lignin, also known as fiber. This fiber produces the characteristic stringy, crisp or fibrous textures associated with vegetables.

Vegetables are also a good source of vitamins and minerals. Care must be taken during preparation to preserve their nutritional content, however. Once peeled or cut, vegetables lo se nutrients to the air or to any liquid in which they are allowed to soak. Vitamins are concentrated just under the skin, so peel vegetables thinly, if at all.

USDA Organic Designation

Great strides in agriculture have been made during the past two centuries. Pesticides, fungicides and herbicides now eliminate or control pests that once would have devoured, ruined or choked crops. Chemical fertilizers increase yields of many of the world's staples. However, not everyone has greeted these developments with open arms.

During the past few decades, scientific and medical investigators have documented, or at least suggested, health risks associated with certain synthetic pesticides, fertilizers and other products. These findings have led to a renewed interest in a now multibillion-dollar-a-year back-to-the-basics approach to farming organic farming. Specialty farms, orchards and even wineries now offer organically grown products (or, in the case of wineries, wines made from organically grown grapes). These products come with few, if any, intentional additives and should be free of any incidental additives. Proponents argue that these products are better for you and better for the health of the farm workers.

The U.S. Department of Agriculture regulates the production and labeling of organically grown foods. It requires that any natural food labeled "100 percent organic" must contain only organic ingredients-that is, those grown and manufactured without the use of added hormones, pesticides, synthetic fertilizers, and so on; soil cannot have been treated with unapproved synthetics for three years for a crop to be called organic. To be labeled organic, or to display the USDA organic seal, processed foods must contain at least 95 percent organic ingredients by weight. Processed foods with 70 to 95 percent organic ingredients may be labeled "made with organic ingredients"; processed foods with less than 70 percent organic ingredients may list those ingredients on the information panel but may not use the term organic anywhere on the front of the package.

Purchasing and Storing Fresh Vegetables

Fresh vegetables should be selected according to seasonal availability. Using a vegetable at the peak of its season has several ad vantages: Price is at its lowest, selection is at its greatest and the vegetable's color, flavor and texture are at their best.

Grading

The USDA has a voluntary grading system for fresh vegetables traded on wholesale markets. The system is based on appearance, condition and other factors affecting waste or eating quality.

Grades for all vegetables include, in descending order of quality, U.S. Extra Fancy, U.S. Fancy, U.S. Extra No. 1 and U.S. No.1. There are also grades that apply only to specific vegetables, for example, U.S. No. 1 Boilers for onions. Consumer or retail grading is currently required only for potatoes, carrots and onions. It uses alphabetical listings, with Grade A being the finest.

Purchasing

Fresh vegetables are old by weight or count. They are packed in cartons referred to as cases, lugs, bushels, flats or crates. The weight or count packed in each of these containers varies depending on the size and type of vegetable as well as the packer. For example, celery is packed in 55-pound cartons containing 18 to 48 heads, depending on the size of each head.

Some of the more common fresh vegetables (for example, onions, carrots, celery and lettuces) can be purchased from wholesalers trimmed, cleaned and cut according to your specifications. Although the unit price will be higher for diced onion s than for whole onions, for example, the savings in time, labor, yield-loss and storage space can be substantial. Processed vegetables may suffer a loss of nutrients, moisture and flavor, however.

Ripening

Although vegetables do not ripen in the same manner as fruits, they do continue to breathe (respire) after harvesting. The faster the respiration rate, the faster the produce ages or decays. This decay results in wilted leaves and dry, tough or woody stems and stalks.

Respiration rates vary according to the vegetable variety, its maturity at harvest and its storage conditions after harvest.

Ripening proceeds more rapidly in the presence of ethylene gas. Ethylene gas is emitted naturally by fruits and vegetables and can be used to encourage further ripening in some produce, especially fruit-vegetables such as tomatoes. Items harvested and shipped when mature but green (unripe) can be exposed to ethylene gas to induce color development (ripening) just before sale.

Storing

Some fresh vegetables are best stored at cool temperatures, between 40°F and 60°F (4°C and 16°C), ideally in a separate produce refrigerator. These include winter squash, potatoes, onions, shallots and garlic. If a produce refrigerator is not available, store these vegetables at room temperature in a dry area with good ventilation. Do not store them in a refrigerator set at conventional temperatures. Colder temperatures convert the starches in these vegetables to sugars, changing their texture and flavor.

Most other vegetables benefit from cold storage at temperatures between 34°F and 40°F (2°C and 4°C) with relatively high levels of humidity. Greens and other delicate vegetables should be stored away from apples, tomatoes, bananas and melons, as the latter give off a great deal of ethylene gas.

Preservation techniques are designed to extend the shelf life of vegetables. These methods include irradiation, canning, freezing and drying. Except for drying, these techniques do not substantially change the vegetable's texture or flavor. Canning and freezing can also be used to preserve cooked vegetables.

Irradiated Vegetables

The irradiation process uses ionizing radiation (usually gamma rays of cobalt 60 or cesium 137) to sterilize foods. When foods are subjected to radiation, parasites, insects and bacteria are destroyed, ripening is slowed and sprouting is prevented. Irradiation works without a noticeable increase in temperature; consequently, the flavor and texture of fresh foods are not affected. Some nutrients, however, may be destroyed. Irradiated vegetables do not need to be sprayed with post-harvest pesticides, and they have an extended shelf life.

The FDA classifies irradiation as a food additive. Although irradiation is not yet approved for all foods, grains, fruits and vegetables may be treated with lowdose radiation. Irradiated foods must be labeled "Treated with radiation" or "Treated by irradiation."

Hydroponics: Working Water

Hydroponics is the science of growing plants without soil in water. Plants are grown in an inert medium such as gravel, peat, sand or other sterile material.
Nutrients are distributed in water that is circulated over the plant's roots. In a hydroponic farm, the temperatures and light are controlled to maximize production. Because hydroponic farm s are indoors, plants can be grown in any climate; both Canada and Holland are major producers of vegetables grown under these conditions.

Canned Vegetable

Canned vegetables are the backbone of menu planning for many food service operations. In commercial canning, raw vegetables are cleaned and placed in a sealed container, then subjected to high temperatures for a specific period. Heating destroys the microorganisms that cause spoilage, and the sealed environment create d by the can eliminates oxidation and retards decomposition. However, the heat required by the canning process also softens the texture of most vegetables and alters their nutritional content; many vitamins and minerals may be lost through the canning process. Green vegetable s may also suffer color loss, becoming a drab olive hue.

Canned vegetables are graded by the USDA as U.S. Grade A or Fancy, U.S. Grade B or Extra-Select, and U.S. Grade C or Standard. U.S. Grade A vegetables must be top quality, tender and free of blemishes. U.S. Grade C vegetables may lack uniformity or flavor, but can be used in casseroles or soups if cost is a concern.

Combinations of vegetables as well as vegetables with seasonings and sauces are available canned. For example, corn kernels are available canned in water, in seasonings and sauces, combined with other vegetables or creamed. Canned vegetables are easy to serve because they are essentially fully cooked during the canning process.

Canned vegetables are purchased in cases of standard-sized cans. Canned vegetables can be stored almost indefinitely at room temperature. Once a can is opened, any unused contents should be transferred to an appropriate storage container and refrigerated. Cans with bulges should be discarded immediately, without opening.

Frozen Vegetables

Frozen vegetables are almost as convenient to use as canned. However, they often require some cooking, and expensive freezer space is necessary if an inventory is to be maintained. Regardless, freezing is a highly effective method for preserving vegetables. It severely inhibits the growth of microorganisms that cause spoilage without destroying many nutrients. Generally, green vegetables retain their color, although the appearance and texture of most vegetables ma y be somewhat altered because of their high water content: Ice crystals form from the water in the cells and burst the cells walls.

Some vegetables are available individually quick-frozen (IQF). This method employs blasts of cold air, refrigerated plates, liquid nitrogen, liquid air or other techniques to chill the vegetables quickly. Speeding the freezing process can greatly reduce the formation of ice crystals.

Combinations of vegetables as well as vegetables with seasonings and sauces are available frozen. Some frozen vegetables are raw when frozen; others are blanched before freezing so that final cooking time is reduced. Many others are fully coo ked before free zing and need only to be thawed or heated for service. Frozen vegetables generally do not need to be thawed before being heated. Once thawed or cooked, they should be stored in the refrigerator and reheated in the same manner as fresh vegetables. Do not refreeze previously frozen vegetables.

Frozen vegetables are graded in the same manner as canned vegetables. They are usually pack d in cases containing 1- to 2-pound (450- to 900-gram) boxes or bags. All frozen vegetables should be sealed in moisture-proof wrapping and kept at a constant temperature of 0°F (-18°C) or below. Temperature fluctuations can draw moisture from the vegetables, ca using poor texture and flavor loss. Adequate packaging also prevents freezer burn, an irreversible change in the color, texture and flavor of frozen foods.

Dried Vegetables

Except for beans, peas, peppers, mushrooms and tomatoes, few vegetables are commonly preserved by drying. Unlike other preservation methods, drying dramatically alters flavor, texture and appearance. The loss of moisture concentrates flavors and sugars and greatly extends shelf life.

Acid/Alkali Reactions

The acid or alkali content of the cooking liquid affects the texture and color of many vegetables. This is of greater concern with moist-heat cooking methods, but it is also a consideration with city-heat cooking methods, as they often call for blanched or parboiled vegetables.

Texture

The acidity or alkalinity of the vegetable's cooking liquid influences the finished product's texture. If an acid such as lemon juice, vinegar or wine is added to the liquid for flavoring, the vegetable will resist softening and will require a longer cooking time. On the other hand, an alkaline cooking medium will quickly soften the vegetable's texture and may cause it to become mushy. Alkalinity also causes nutrient loss (especially thiamin) and may impart a bitter flavor. Alkalinity can be caused by tap water, detergent residue on utensils or the addition of baking soda (a base) to the cooking liquid. (You could add, for example, 1/8 teaspoon [0.6 milliliter) baking soda per cup [225 milliliters] of beans to speed the softening of dried beans.)

Color

The acidity or alkalinity of the liquid also affects the plant's pigments, causing both desirable and undesirable color changes. There are three principal pigment categories: chlorophyll, carotenoid and flavonoid. A plant's unique color is the result of a combination of these pigments. Chlorophyll pigments predominate in green vegetables such as spinach, green beans and broccoli. Carotenoid pigments predominate in orange and yellow vegetables such as carrots, tomatoes, reel peppers and winter squashes. Flavonoid pigments predominate in reel, purple and white vegetables such as red cabbage, beets and cauliflower.

Initially, as vegetables are cooked, their original colors intensify. Exposure to heat makes pigments, especially chlorophyll, appear brighter. Exposure to acids and bases affects both chlorophyll and flavonoid pigments. Acids will gradually turn green vegetables an olive-drab color, while a slight alkalinity promote s chlorophyll retention. The opposite occurs with vegetables containing flavonoids: They retain desirable colors in a slightly acidic environment while losing colors in an alkaline one. (Carotenoids are not affected by either acidity or alkalinity.) Color changes alone do not affect flavor, but the altered appearance can make the product so visually unappealing as to become inedible.

Colors also change as the naturally occurring acids in vegetables are released during cooking. If the cooking pan is kept covered, the acids can concentrate, creating richer flavonoid pigments but destroying chlorophyll pigments.

Thus, if color is the one and only concern, vegetables with a high amount of chlorophyll should be cooked in an alkaline liquid, and vegetables, with a high amount of flavonoids should be cooked in an acidic liquid. Remember, the improvement in color usually comes at the expense of texture and nutrients.

Acid & Alkali Reactions

			Effects of Acid on:		Effect of Alkali on:
VEGETABLE	PIGMENT FAMILY	COLOR	TEXTURE	COLOR	TEXTURE	COOK COVERED
Spinach, broccoli	chlorophyll	drab olive green	firm	bright green	mushy	no
Carrots, rutabagas	carotenoid	no change	firm	no change	mushy	no difference
Cauliflower	flavonoid	white	firm	yellow	mushy	yes
Red cabbage	flavonoid	red	firm	blue	mushy	yes

*Alkalinity always causes a loss of thiamin and other nutrients

Guidelines for Vegetable Cookery

The following general guidelines for vegetable cookery should be considered regardless of the cooking method used:

1. Vegetables should be carefully cut into uniform shapes and sizes to promote even cooking and provide an attractive finished product.
2. Cook vegetables for as short a time as possible to preserve texture, color and nutrients.
3. Cook vegetables as close to service time as possible. Holding vegetables in a steam tab le continues to cook them.
4. When necessary, vegetables may be blanched in advance, refreshed in ice water and refrigerated. They can then be reheated as needed.
5. White and red vegetables (those with flavonoid pigments) may be cooked with a small amount of acid such as lemon juice, vinegar or white wine to help retain their color.
6. When preparing an assortment of vegetables, cook each type separately, and then combine them. Otherwise, some items would become overcooked in the time required to properly cook others.

Doneness

There are so many types of vegetables, with such varied responses to cooking, that no one standard for doneness is appropriate. Each item should be evaluated on a recipe-by-recipe basis. Generally, however, most cooked vegetables are done when they are just tender when pierced with a fork or the tip of a paring knife. Leafy vegetables should be wilted but still have a bright color.

Avoid overcooking vegetables by remembering that some carryover cooking will occur through the residual heat contained in the foods. Always rely on subjective tests-sight, feel, taste and aroma- rather than the clock.

Dry-Heat Cooking Methods

Broiling and Grilling

Broiling and grilling use high heat to cook vegetables quickly. This preserves their nutritional content and natural flavors. The radiant heat of the broiler or grill caramelizes the vegetables, creating a pleasant flavor that is not generally achieved when vegetables are cooked by other methods.

Selecting and Preparing Vegetables to Broil or Grill

Broiling is often used to cook soft vegetables such as tomatoes or items that might not rest easily on a grill rack. Broiling is also used to warm and brown items just before service. If necessary, the vegetables can be basted to prevent them from drying out under the broiler's direct heat. Sometimes a cooked vegetable is napped with sauce or clarified butter and placed briefly under the broiler as a finishing touch at service time.

A large range of vegetables can be grilled. Carrots, peppers, squashes, eggplants and similar vegetables should be cut into broad, thin slices. They can then be placed on the grill in the same manner as a portion of meat or fish to create attractive crosshatchings. Smaller vegetables such as mushrooms, cherry tomatoes and pearl onions can be threaded onto skewers for easy handling. (Bamboo or wooden skewers should be soaked in cold water for 15 minutes before using to help prevent them from burning on the grill.)

Seasoning Vegetables to Be Broiled or Grilled

Vegetables contain little fat and therefore benefit greatly from added fat when being broiled or grilled. The added fat can be a brushing of clarified butter or a marinade such as one made from olive oil and herbs. Some vegetables may be brushed with butter and coated with breadcrumbs or Parmesan before broiling.

Roasting and Baking

The terms roasting and baking are used interchangeably when referring to vegetables. Roasting or baking is used to bring out the natural sweetness of many vegetables while preserving their nutritional value s. The procedures are the same as those for roasting meats.

Selecting and Preparing Vegetables to Roast or Bake

Hearty vegetables such as winter squash and eggplant are especially well suited for roasting or baking. Vegetables such as onions, carrots and turnips are sometimes cooked alongside roasting meats or poultry. The vegetables add flavor to the finished roast and accompanying sauce, and the fats and juices released from the cooking roast add flavor to the vegetables.

Seasoning Vegetables to Be Roasted or Baked

Vegetables may be seasoned with salt and pepper, and rubbed with butter, or oil, before baking, or they may be seasoned afterward with a wide variety of herbs and spices. Some vegetables, such as winter squashes and sweet potatoes, may be seasoned with brown sugar or honey as well.

Sauteing

Sautéed vegetables should be brightly colored and slightly crisp when done and show little moisture loss. When sautéing vegetables, all preparation must be complete before cooking begins because timing is important and cooking progresses rapidly. Have all vegetables, herbs, spices, seasonings and sauces ready before beginning.

Selecting and Preparing Vegetables to Sauté

A wide variety of vegetables can be sautéed. Whatever vegetables are used, they should be cut into uniform-sized pieces to ensure even cooking. Quick-cooking vegetables such as summer squashes, onions, greens, stalks, fruit-vegetables and mushrooms can be sautéed without any preparation except washing and cutting. Other vegetables such as Brussels sprouts, green beans, winter squashes, broccoli, cauliflower and most root vegetables are usually first.

Pan-Frying

Pan-frying is not as popular as other techniques for cooking vegetables. Green tomatoes, however, are sometimes seasoned, floured and pan-fried; eggplant slices are seasoned, floured, pan-fried and used for eggplant Parmesan.

Deep-Frying

Deep-frying is a popular method of preparing vegetables such as potatoes, squashes and mushrooms. They can be served as hors d'oeuvre, appetizers or accompaniments to a main dish. Vegetables can also be grated or chopped and incorporated into fritters or croquettes. Any deep-fried item should have a crisp, golden exterior with a tender, non-greasy center.

Selecting and Seasoning Vegetables to Be Deep-Fried

Except for potatoes, most vegetables are breaded or battered before deep -frying. Slow cooking vegetables such as broccoli and cauliflower should be blanched in boiling water before breading or battering. Blanching speeds cooking and allows the interior to cook completely before the surface bums.

Although vegetables that will be deep-fried can be marinated or seasoned directly, it is more common to season the batter or breading that will cover them. Additional flavors come from the sauces and accompaniments served with the deep-fried vegetables. Creamy herb dressings, spicy tomato, or soy-based dipping sauces.

Moist-Heat Cooking Methods

Blanching and Parboiling

Blanching and parboiling are variations on boiling; the difference between them is the length of cooking time. Blanched and parboiled vegetables are often finished by other cooking methods such as sautéing.

Blanching is the partial cooking of foods in a large amount of boiling water for a very short time, usually only a few seconds. Besides preparing vegetables for further cooking, blanching is used to remove strong or bitter flavors, soften firm foods, set colors or loosen skins for peeling. Kale, chard, snow peas and tomatoes are examples of vegetables that are sometimes blanched for purposes other than preparation for further cooking.

Parboiling is the same as blanching, but the cooking time is longer, usually several minutes. Parboiling is used to soften vegetables and shorten final cooking times. Parboiling is commonly used for preparing root vegetables, cauliflower, broccoli and winter squashes.

Boiling

Vegetables are often boiled. Boiled vegetables can be served as they are, or they can be further pre pared by quickly sautéing with other ingredients, pureeing or mashing. Boiled vegetables are also chilled and used in salads.

Starchy root vegetables are generally not boiled but rather simmered slowly so that the heat penetrates to their interiors and cooks them evenly. Green vegetables should be boiled quickly in a large amount of water in order to retain their color and flavor.

Refreshing

Unless the boiled, blanched or parboiled vegetables will be eaten immediately, they must be quickly chilled in ice water after they are removed from the cooking liquid. This prevents further cooking, preserves, and maintains their colors. This process is known as refreshing or shocking the vegetables. The vegetables are removed from the ice water as soon as they are cold. Never soak or hold the vegetables in the water longer than necessary, or valuable nutrients and flavor will be leached away.

Selecting and Preparing Vegetables to Boil

Nearly any type of vegetable can be boiled. Carrots, cabbages, green beans, turnips and red beets are just a few of the most common ones. Vegetables can be large or small, but they should be uniform in size to ensure even cooking. Some vegetables are cooked whole and require only washing before boiling. Others must be washed, peeled, and trimmed, or cut into smaller sizes.

Seasoning Vegetables to Be Boiled

Often vegetables are boiled in nothing more than salted water. Lemon juice, citrus zest, wine and other acidic ingredients are sometimes added to white and red vegetables; if so, they should be added to the liquid before the vegetables. Herbs and spices in a sachet or a bouquet garni are often used to add flavor to boiled vegetables and should be added according to the recipe. After boiling, vegetables are sometimes finished with herbs, spices, butter, cream or sauces.

Steaming

Vegetables can be steamed in a convection steamer or by placing them in a basket or on a rack and suspending them over boiling liquid in a wok, saucepan, or hotel pan. Vegetables can also be pan-steamed by cooking them in a covered pan with a small amount or liquid; most of the cooking is clone by steam because only a small portion of the food is submerged in the liquid. Steamed vegetables can be eaten plain, partially cooked and sautéed lightly to finish, incorporated into casseroles or pureed. If they are not served immediately, they must be refreshed and refrigerated until used.

Properly steamed vegetables should be moist and tender. They generally retain their shape better than boiled vegetables. Vegetables cook very rapidly in steam, and overcooking is a common mistake.

Selecting and Preparing Vegetables to Steam

Nearly any vegetable that can be boiled can also be steamed successfully. All vegetables should he washed, peeled and trimmed if appropriate and cut into uniform-sized pieces. Pan-steaming is appropriate for vegetables that are small or cut into fairly small pieces such as peas and beans or broccoli and cauliflower florets.

Seasoning Vegetables to Be Steamed

Steaming produces vegetables with clean, natural flavors. Foods cooked in convection steamers can be seasoned with herbs and spices; convection steamers use plain water to produce steam, so the foods being coo ked do not gain flavor from the cooking liquid. Vegetables steamed over liquids or pan-steamed in small amounts of liquids can be flavored by using stocks or court bouillon as the cooking liquid. Herbs, spices and aromatic vegetables can be added to any liquid for additional flavor.

Combination Cooking Methods

Braising and Stewing

Braised and stewed vegetables are cooked slowly in a small amount of liquid. The liquid, including any given off by the vegetables, is reduced to a light sauce, becoming part of the finished product. Generally, a braised dish is prepared, with only one vegetable; a stew is a mixture of several vegetables. The main ingredients are sometimes browned in fat before the liquid is added in order to enhance flavor and color.

Both braises and stews can be exceptionally flavorful because they are served with their entire coo king liquid. (Boiled vegetables lose some of their flavor to the cooking liquid.) Braised and stewed vegetables generally can be held hot for service longer than vegetables prepared by other cooking methods.

Selecting and Preparing Vegetables to Braise or Stew

Various lettuces, especially romaine and Boston, are often braised. Cabbages, Belgium endive, leeks and many other vegetables are also commonly braised. Stews may contain a wide variety of vegetables such as summer squashes, eggplant, onions, peppers, tomatoes, carrots, celery and garlic. Leafy green vegetables and winter squashes are less commonly braised or stewed.

The vegetables should be washed and peeled or trimmed if appropriate. Vegetables to be braised may be left whole, cut into uniform pieces or shredded, as desired. Lettuces are usually cut into halves or quarters; cabbage is usually shredded.

Seasoning Vegetables to Be Braised or Stewed

Both braises and stews usually include flavoring ingredients such as garlic, herbs, bacon or mirepoix. The liquid may consist of water, wine, stock or tomato juice. Vegetables can even be braised in butter and sugar or honey to create a glazed dish. Both braises and stews can be seasoned with a variety of herbs and spices. Acid the seasonings before cove ring the pot to finish the cooking process. Strongly flavored vegetables such as celery root and turnips are usually parboiled.

Microwaving

Fresh vegetables are among the few foods that can be consistently well prepared in a microwave oven. Often microwave cooking can be accomplished without any additional liquid, thus preserving nutrients. With microwaving, colors and flavors stay true, and textures remain crisp.

Microwave cooking is actually a form of steaming. As explained in Chapter 10, Principles of Cooking, microwaves agitate water molecules, thus creating steam. The water may be the moisture found naturally in the food or may be added specifically to create the steam. Cooking time depends on the type or microwave oven as well as on the freshness, moisture content, maturity and quantity or vegetables being prepared.

Selecting and Preparing Vegetables to Microwave

Any vegetable that can be steamed successfully can be microwaved with good results. Because typical microwave ovens are relatively small, they are impractical for producing large quantities of food. They are most useful for reheating small portions of vegetables that have been blanched or partially cooked using another cooking method.

Seasoning Vegetables to Be Microwaved

Microwaving, like steaming, brings out the natural flavors of food. Herbs and spices can be added to the vegetables before they are microwaved. Alternatively, after microwaving, the vegetables can be tossed with butter, herbs and spices or combined with a sauce.

Pureeing

Pureeing is a technique often used with vegetables. Cooked vegetable purees can be served as is, or they can be used as an ingredient in other preparations such as pumpkin pie, mashed potatoes or vegetable soufflés. Purees can also be bound with eggs or seasoned and used to make vegetable timbales and terrines.

Pureed vegetables are generally first cooked by baking, boiling, steaming or microwaving. White, red and yellow vegetables should be cooked until quite soft. They are more easily pureed when hot or warm; this also helps ensure a smooth finished puree. For most preparations, green vegetables must be refreshed after cooking and pureed while cold, or they will overcook and become discolored.

Seasoning Vegetables to Be Pureed

Vegetables for purees can be seasoned before they are pureed following the guidelines for the cooking procedure used. They can also be seasoned after they are pureed with a wide variety of ingredients such as herbs, spices, cheese, honey or brown sugar.

Applying Various Cooking Methods

Vegetables are cooked in order to break down their cellulose and gelatinize their starches. Cooking gives vegetables a pleasant flavor; creates a softer, tenderer texture; and makes them more digestible. Ideally, most vegetables should be cooked as briefly as possible in order to preserve their flavor, nutrients and texture. Unfortunately, sometimes one must choose between emphasizing appearance and maintaining nutrition because cooking methods that preserve color and texture often remove nutrients.