Vegetable Cooking St. Michael’s C.H.S. TFJ4C

A) Controlling Quality Changes As a cook, you have a choice of many kinds of vegetables and many cooking methods. Not surprisingly then, you are faced with the necessity of learning many rules for cooking vegetables Cooking affects vegetables in four ways Texture – Fibre, starch and Doneness Flavour Colour Nutrients

Controlling Texture: Changing texture is one of the main purposes of cooking vegetables. FIBRE – fibre structures (including cellulose and pectins) give them shape and firmness. Cooking softens some of these components. Fibre varies In different vegetables (spinach and tomatoes versus carrots and turnips) In different examples of the same vegetable (old versus young) In the same vegetable (tender tips of asparagus and broccoli have less fibre than the stalks).

Fibre is made firmer … By acids. Lemon juice, vinegar, and tomato products RESULT – Longer cooking times By sugars. Sugar strengthens the cell structure. In fruit cookery – cooking pears in simple syrup makes them firmer. Cooking apples till soft and then sweeten for apple sauce. RESULT – cook vegetables first and then add the syrup or sugar.

Fibre is made softer… By heat. By alkalis In general, longer cooking means softer vegetables. By alkalis DO NOT add baking soda to green vegetables. Not only does it destroy vitamins but it also makes the vegetables unpleasantly mushy.

Starch Starch is another component that affects textures. DRY STARCH FOODS – dried legumes (beans, lentils, peas), rice and macaroni products must be cooked in enough water for the starch to absorb moisture and soften. Dried beans are usually soaked before cooking to replace lost moisture in the drying process.

Starch MOIST STARCH – like potatoes and sweet potatoes have enough moisture of their own, but they still need to be cooked until the starch granules soften.

Doneness Vegetables are said to be done when they reach the desired degree of tenderness. This stage varies from vegetable to vegetable. Squash and eggplant – quite soft Most vegetables are cooked briefly until they are crisp-tender (al-dente – firm to the bite) At the proper stage of doneness, they not only have the most pleasing texture but also retain the maximum flavour, colour and nutrients.

Guideline for achieving proper doneness Don’t overcook Cook as close to service as possible. Avoid steam tables. If they are being cooked ahead of time, undercook them, cool rapidly in ice water bath, and refrigerate. For uniform doneness, cut uniform sizes. Vegetables with both tough and tender parts need to be properly prepared. Peel woody stalks of asparagus Peel and split broccoli stalks Pierce the base of Brussels sprouts Remove the centre stalks of cabbage leaves before braising Don’t mix batches of vegetables. They require different times.

B) Controlling Flavour Changes Cooking produces Flavour Loss Many flavours are lost during the cooking process. The longer a vegetable is cooked, the greater the loss of flavour.

4 ways to control flavour loss Cook for as short a time as possible Use boiling salted water. Stirring vegetables in boiling water shortens the cooking time. The addition of salt helps to reduce flavour loss. Use just enough water to cover – this prevents leaching. Steam vegetables whenever possible. Steam cooking reduces leaching and shortens the cooking time.

Allowing Flavour loss Some vegetables – onion family and cabbage family are very pungent Cook in large amounts of water – and do not cover. This will allow for leaching and for flavours to escape.

Cooking Produces Flavour Changes Cooked vegetables do not taste like uncooked vegetables, because the cooking process causes chemical changes. As long as the vegetables are not overcooked, the changes are desirable.

Cooking and Sweetness Young, freshly harvested vegetables have a relatively high sugar content that makes them taste sweet. As they mature, or sit in storage, the sugar gradually changes to starch. This is especially noticeable in Corn, peas, carrots, turnips, and beets. RESULT: Select fresh, young vegetables If you have to use older vegetables, cook with a little sugar to replace the lost sweetness.

C) Controlling Colour Changes Intro – Colour plays an important role in making the food appealing to the customer. Therefore, it is important to try and retain as much colour as possible during the cooking process. Pigments are compounds that give the vegetables their colour. Different pigments react in different ways to heat. To acids, and to other elements that might be introduced during the cooking process.

White Vegetables Pigments called anthoxanthins and flavonoids range from yellow to white and give some vegetables their colour. White pigments stay white in acid but not in alkaline water. SOLUTION: add lemon juice, or cream of tartar to cooking water. (not too much or this might toughen the vegetables) Covering the pot helps keep the acids in.

Red Vegetables The Pigment called anthocyanins are found in red cabbage, beets, and blueberries. (This is not found in tomatoes or red peppers – orange/ yellow pigments). Acids turn these bright red. Red beets and red cabbage are cooked with a tart apple (acidic) for this reason. Alkalis turn these blue- Solution: Adding acid will toughen vegetables – add only a small amount in the water – cook longer – add more acid when vegetables are tender.

Green Vegetables Green pigment is called chlorophyll. Acids are enemies of green vegetables. Both acids and longer cooking times turn green vegetables to a drab olive green. Cook uncovered to allow plant acids to escape. Cook for the shortest time Cook in small batches as needed rather than hold for long times. NOTE: A large amount of water helps to leach plant acids, helps preserve colour, and speeds cooking.

Yellow/ Orange Vegetables The yellow/orange colour pigment is called carotenoids. These pigments are very stable and are therefore not affected by acids or alkalis Long cooking times can dull the vibrant colour Shortened cooking times will actually keep the bright colour, but will also maintain vitamins and flavours.

D) Controlling Nutrition Loss Vegetables are our major sources of essential vitamins (A and C) and other nutrients. Unfortunately, during the cooking process many of these nutrients are lost.

6 Factors responsible for Nutrient loss High Temperature Long cooking times Leaching Alkalis (baking soda, hard water) Plant enzyme (which are active in warm temperatures but destroyed in high heat) Oxygen

Difficult to avoid Pressure cooking = short time/ high temp Braising = low temp/ long time Baking = long time/ high temp; no leaching Boiling = faster than simmer/ high temp/ leaching Cutting vegetables in small pieces = less cooking time/ increased leaching Steaming = some leaching from steam vapors/ high temp.