2Controlling Quality Changes During Cooking Cooking affects vegetables in four ways. It changes the following:TextureFlavorColorNutrients
3Controlling Texture Changes FiberThe amount of fiber varies:In different vegetables.In mature vs. younger vegetables.In different parts of the same vegetable.
4Controlling Texture Changes FiberFiber is made firmer by:AcidsSugarsFiber is softened by:HeatAlkalis
5Controlling Texture Changes StarchDry starchy foods must be cooked in enough water for the starch granules to absorb moisture and soften (gelatinize).Moist starchy vegetables have enough moisture of their own to soften (gelatinize) the starch granules.They must still be cooked until the starch granules soften.
6Controlling Texture Changes DonenessA vegetable is said to be done when it reaches the desired degree of tenderness.Some, such as winter squash, eggplant, and braised celery, are considered properly cooked when they are quite soft.Most vegetables are best cooked very briefly, until they are crisp-tender or al dente (firm to the bite).
7Controlling Flavor Changes Cooking Produces Flavor LossFlavor loss can be controlled in several ways:Cook for as short a time as possible.Use boiling salted water.Starting vegetables in boiling water shortens cooking time.The addition of salt helps reduce flavor loss.Use just enough water to cover food.Minimizes leaching of flavor, color and nutrients.Steam vegetables whenever appropriate.Reduces leaching out of flavor.Shortens cooking time.
8Controlling Flavor Changes Cooking and SweetnessYoung, freshly harvested vegetables have a relatively high sugar content that makes them taste sweet.As they mature, or as they sit in storage, the sugar gradually changes to starch.Try to serve young, fresh vegetables that have been stored as short a time as possible.
9Controlling Color Changes Cooking Produces Flavor LossCooking produces certain chemical changes.As long as the vegetables are not overcooked, this change is desirable.Overcooking produces undesirable changes.Especially in members of the cabbage family.They develop a strong, unpleasant flavor.
10Controlling Color Changes White VegetablesPigments are compounds that give vegetables their color.Pigments called anthoxanthins (an-tho-zan-thins) and flavonoids range from pale yellow to white.White pigments stay white in acid and turn yellow in alkaline water.
11Controlling Color Changes Red VegetablesRed pigments, called anthocyanins, are found in only a few vegetables.Mainly red cabbage and beets.Acids turn anthocyanins a brighter red.Alkalis turn anthocyanins blue or blue-green (not a very appetizing color).
12Controlling Color Changes Green VegetablesChlorophyll is present in all green plants.Acids are enemies of green vegetables.Both acid and long cooking turn green vegetables a drab olive green.
13Controlling Color Changes Green VegetablesProtect the color of green vegetables by:Cooking uncovered to allow plant acids to escape.Cooking for the shortest possible time. Properly cooked green vegetables are tender crisp, not mushy.Cooking in small batches rather than holding for long periods in a steam table.Do not use baking soda to maintain green color.Alkalis destroy vitamins and makes texture unpleasantly mushy and slippery.
14Controlling Color Changes Yellow and Orange VegetablesCarotenoids: Yellow and orange pigmentsThese pigments are very stable.Little affected by acids or alkalis.Short cooking prevents dulling of the color and preserves vitamins and flavors.
15Controlling Nutrient Losses Six factors are responsible for most nutrient loss:High temperatureLong cookingLeaching (dissolving out)Alkalis (baking soda, hard water)Plant enzymes (which are active at warm temperatures but destroyed by high heat)Oxygen
16Controlling Nutrient Losses Cooking in a Little Liquid Versus a Lot of LiquidUsing a lot of liquid increases vitamin loss by leaching.Using a little liquid increases cooking time.Tests have shown that, for these reasons, no more nutrients are lost when vegetables are cooked in a lot of water than when vegetables are cooked in just enough water to cover.
17General Rules of Vegetable Cookery Do not overcook.Cook as close to service time as possible, and in small quantities.Avoid holding for long periods on a steam table.If the vegetable must be cooked ahead of time:Undercook slightly and chill rapidly.Reheat at service time.Never use baking soda with green vegetables.
18General Rules of Vegetable Cookery Cut vegetables uniformly for even cooking.Start with boiling, salted water when boiling green vegetables and other vegetables that grow above the ground.Roots and tubers are started in cold, salted water for more even cooking.Cook green vegetables and strong-flavored vegetables uncovered.
19General Rules of Vegetable Cookery To preserve color, cook red and white vegetables in a slightly acid (not strongly acid) liquid.Cook green vegetables in a neutral liquid.Do not mix a batch of freshly cooked vegetables with a batch of the same vegetable that was cooked earlier and kept hot in a steam table.
20Standards of Quality in Cooked Vegetables ColorBright, natural colorsAppearance on plateCut neatly and uniformly. Not broken upTextureCooked to the right degree of donenessFlavorFull, natural flavor and sweetness
21Standards of Quality in Cooked Vegetables SeasoningsLightly and appropriately seasoned.SaucesButter and seasoned butters should be fresh and not used heavily.Vegetable combinationsFlavors, colors, and shapes should be pleasing in combination.
22Handling Vegetables Washing Wash all vegetables thoroughly Root Vegetables should be scrubbed with a stiff vegetable brush.Wash green, leafy vegetables in several changes of cold water.After washing, drain well and refrigerate lightly covered.
23Handling Vegetables Soaking Do not soak vegetables for long periods. Flavor and nutrients leach out.Dried legumes are soaked for several hours before cooking to replace moisture lost in drying.Dried beans absorb their weight in water.
24Handling Vegetables Peeling and Cutting Peel most vegetables as thinly as possible.Cut vegetables into uniform pieces for even cooking.Peel and cut vegetables as close to cooking time as possible.Treat vegetables that brown easily with an acid, such as lemon juice, or an antioxidant solution or hold under water until ready to use (some vitamins and minerals will be lost).Save edible trim for soups, stocks, and vegetable purées.
25Classifying Vegetables Handling VegetablesClassifying VegetablesThere are many ways of classifying vegetables:The gourd familySeeds and podsRoots and tubersThe cabbage familyThe onion familyLeafy greensStalks, stems, and shootsMushroomsOther tender-fruited vegetables
26Handling Frozen Vegetables Processed VegetablesHandling Frozen VegetablesChecking QualityTemperatureLarge ice crystalsSigns of leaking on the cartonFreezer burn
27Handling Canned Vegetables Processed VegetablesHandling Canned VegetablesChecking QualityReject damaged cans on receiptPuffed or swollen cans indicate spoilage.Know the drained weightTypical drained weights are 60 to 65 percent of total contents.Check the grade
28Production and Holding Problems in Quantity Cooking Batch Cooking and Blanch-and-ChillBatch Cooking involves dividing the food into smaller batches and cooking them one at a time, as needed.Blanch and Chill involves partially cooking, chilling, and finish-cooking.It is not as good, nutritionally, as cooking completely to order, but it is almost as good.
29Storage Fresh Vegetables Potatoes, onions, and winter squash are stored at cool temperatures.(50–65°F/10–18°C) in a dry, dark placeOther vegetables must be refrigerated.Peeled and cut vegetables need extra protection from drying and oxidation.Cover or wrap, and use quickly to prevent spoilage.
30Storage Frozen Vegetables Store at 0°F (–18°C) or colder, in original containers, until ready for useDo not refreeze thawed vegetables.LeftoversThe best way to store leftovers is not to create them in the first place.Do not mix batches.