NUTRITIONAL VALUE OF FOODS



NUTRITIONAL VALUE OF FOODS

A characteristic of all living organisms is the intake of nutritional substances, nutrients, necessary for their life. Nutrients include proteins, fats, carbohydrates, minerals and vitamins. A fundamental function of human body is to metabolise the food constituents into energy. Energy metabolism is customarily expressed in terms of the calorie, which is a heat unit of energy. By convention a large calorie equivalent to the kilocalorie (kcal or Cal) is adopted in measuring energy. The only sources of calories are proteins, fats, carbohydrates and alcohol. They have a different calorific value: 1 g of pure protein will yield 4 calories, 1 g of pure fat will yield 9 calories, 1 g of pure carbohydrate will yield 4 calories and 1 gram of pure alcohol will yeld 7 calories. It results that the calorific value of foods largely depends on the fats they contain. In addition to their calorific value, foods have a biological value in that they provide human body with the fundamental substances necessary to its development. These substances are the proteins. Protein-rich foods come from animal or plant origin. Proteins are needed for the growth and repair of tissues. Lack of protein affects physical growth and mental development. The following table shows the distribution of nutrients in foods:

|NUTRIENTS |FOODS |

|Proteins |Proteins are organic compounds that in the diet serve primarily to build and |

| |maintain cells. They are responsible for muscle contraction, digestion, immune |

| |system and carry vital substances throughout the body. They are derived from food |

| |and in particular from meat, fish, poultry, eggs, milk, dairy, cheese, cereals |

| |(wheat, barley, rye, corn, millet, etc), legumes (peas, beans, lentils, broad beans |

| |). |

|Fats |Dietary fat is a compound that is derived from both plant and animal sources. As a |

| |nutrient it helps support cell walls, provides a concentrated source of energy, |

| |insulates and protects vital organs and aids in the metabolism of vitamins. Fats may|

| |be saturated and unsaturated. Saturated fats are found in meats, dairy products and |

| |tropical oils. Unsaturated fat is found primarily in vegetable oils and fish, as |

| |well as in margarine. |

|Carbohydrates |Carbohydrates are the most abundant substances found in nature. They form the |

| |connective tissue of cells and are a primary source of energy. A large part of the |

| |human diet consists in carbohydrates in the form of starches which are found in the |

| |grains, the legumes, the tubers and sugars which are found in plants and fruits. |

| |Bread, flour, pasta, rice, sugar, honey, fruit, legumes, and potatoes contain |

| |carbohydrates. |

|Minerals |Minerals are necessary to the structural composition of human body. They affect the |

| |development of bones and teeth, energy metabolism, the nervous system. The most |

| |important ones which must be supplied in the diet are: |

| |calcium, which is provided by milk, dairy products, cheese, yolk, roots, vegetables;|

| |phosphorus which is found in milk, dairy products, cheese, yolk, meat, fish, |

| |potatoes, carrots; iron in yolk, legumes, spinach; iodine in seafish (cod, cod oil, |

| |lobster, herring, oyster). |

|Vitamins |Vitamins are organic compounds whose function is to enhance nutrients’ metabolism. |

| |They are distributed in milk and dairy products, meat, fish, eggs, legumes, bread |

| |and pasta, citrus fruits (oranges, lemons, tangerines), fruit and vegetables |

| |(cauliflower, chicory, endive, lettuce, spinach, courgette, apples, pears, peaches, |

| |apricots, plums). |

The following diagram sums up nutrients specific roles:

The value of minerals and vitamins

It is essential to know some basic facts regarding the benefits our body draws from minerals and vitamins. A proper knowledge of this helps both caterers and customers to be more discerning when choosing food.

| |Benefits |Sources |

|calcium |builds strong bones and teeth |almonds, broccoli, cheese, milk, whole |

| | |grains, yogurt |

|copper |essential for red blood cell formation |cabbage, kidney, nuts, poultry, whole |

| | |grains |

|iodine |important for thyroid gland function. Lack of iodine |salt, sea salt, seafood |

| |leads to hair loss and dry and wrinkled skin | |

|iron |transports oxygen throughout the body |dark green vegetables, lean meat, soya |

|magnesium |essential for nerves and muscles, helps cell |almonds, egg yolk, nuts, sea salt, |

| |metabolism |spinach, whole grains |

|phosphorous |strengthens bones |cheese, egg yolk, fish, meat, whole grains|

|potassium |maintains fluid balance; important for muscles and |bananas, citrus fruits, green vegetables, |

| |nerves |potatoes, whole grains |

|zinc |controls blood sugar and activate enzymes |beans, eggs, fish, onion, whole grain |

| | | |

|Vitamin A |vital for healthy skin, eyes, bones, hair and teeth |apricots, dark green vegetables, carrots, |

| | |kidney, liver |

|Vitamin B1 (thiamine) |releases energy from carbohydrates, assists |green vegetables, wheatgerm, wholegrain |

| |functioning of the heart, liver and nevous system |cereals |

|Vitamin B2 (riboflavin) |releases energy from foods, necessary for healthy skin|cheese, eggs, green vegetables, kidney |

| |and eyes |liver, milk, poultry |

|Vitamin B6 (pyridoxine) |plays a vital role in protein and fat metabolism; |brewers’ yeast, meats, nuts, whole grains |

| |regulates the central nervous system | |

|Vitamin b12 (cobalamin) |necessary for healthy nervous system; forms red blood |eggs, fish, liver, meat, soybeans |

| |cells. | |

|Vitamin C |important for maintenance of bones, teeth, collagen |citrus fruits, cabbage, broccoli, |

| |and blood vessels. It helps heal wounds and mend |tomatoes, potatoes |

| |fractures, and aids in resisting bacteria infections. | |

|Vitamin D |important for bone and teeth development |sunlight, egg yolk, fish-liver oil, milk |

| | |and milk products |

|Vitamin E |helps protect red blood cells |eggs, green vegetables, margarine, |

| | |peanuts, vegetable oils, wheat germs, |

| | |whole grains |

FOOD GROUPS

Foods can be classified into several groups:

1. Milk and Dairy products (milk, yoghurt, ice cream, milk shake, cheese, butter). Milk has a high nutritional value. It is rich in calcium, and phosphorus and contains vitamin A, riboflavin (vitamin B2) and carbohydrate (lactose).

1. Meat, Fish, Poultry and Eggs. This group includes a variety of meats (beef, veal, lamb, pork), fish and shellfish, poultry and eggs. The main nutrients are proteins, fats, minerals and vitamins (Thiamine, riboflavin, niacin, B vitamins). Beef liver is an excellent source of iron and vitamin A.

1. Legumes (peas, chickpeas, beans, broadbeans, lentils, soya seeds) and cereals (wheat, barley, maize/corn, millet, oats, rice, rye, sorghum). Cereals are very rich in starch and carbohydrates.

1. Bread, Pasta and Starchy Food. This group includes white and brown bread, bread-sticks, flour, brown and wild rice, couscous, barley, millet, cornmeal, polenta, cornflakes, branflakes, biscuits, cakes, crackers, spaghetti, noodles, pies, potatoes and chestnuts. They provide proteins, carbohydrates, vitamins and iron. The whole grain products contribute significant quantities of fibre, vitamins and minerals. Bread contributes complex carbohydrates. Apart the ordinary sliced white bread and the varieties for sandwiches and toast, bread includes whole-grain bread, crackers, oatmeal, rye, semolina bread, cornbread, English muffins, bagels, Swedish-style crispbreads, bread shells for pizza. Pasta is a good nutritious food: it contains very little fat and is loaded with complex carbohydrates which are a main source of energy.

1. Citrus Fruits (oranges, lemons, mandarins/tangerins, grapefruit, limes) and Tomatoes. They all supply large amount of vitamin C. The juice and grated peel of lemons and limes add fat free flavour to foods. Tomatoes contribute appreciable quantities of iron, calcium and potassium.

1. Fruits and Vegetables. Fruits are rich in minerals and vitamins. Grapes, peaches, plums, apples and pears are high in fibre. Other fruits such as apricots, figs, prunes, dates, and raisins are good sources of iron and potassium. Vegetables are also an important source of minerals, vitamins and cellulose. Beans, peas and broccoli supply large amounts of calcium and iron. Orange-yellow vegetables (carrots, squash, sweet potatoes) are good sources of beta-carotene.

1. Other Ingredients (butter, margarine, oils, sugars, fats. They generally are added to food during preparation. They supply a large amount of calories and make food more tasty. Products with high levels of unsaturated fat include olive oil, peanut oil, canola oil, sunflower oil.

Nowdays more and more restaurant customers are becoming cautious of their dietary requirements. A small number of people are likely to be particularly interested in, for example, the calorie content of specific menu items or in vegetarian items.

In order to meet normal nutritional needs it is recommended that caterers offer a variety of foods daily, including fruits, vegetables, grain products, dairy products, meats, poultry, fish, and eggs. The greater the variety of foods eaten, the less likely is a deficiency or excess of any single nutrient to develop.

Let’s now examine the nutritive value (calories, proteins, etc.) of some foods from various groups:

| |BREAD GROUP |FRUIT & VEGETABLE |MILK & DAIRY |MEAT & FISH |FATS & SWEETS |

| |brownroll |

|sausages, cakes, biscuits, crisps, pastries, chocolate, sauces,|cakes, biscuits, pastries, scones, buns, pies, sponges, tarts, |

|fried foods, milk, butter, cheese, margarine, lard, egg yolk, |croissants, trifles, cornets, ice-creams, preserves, jams, |

|nuts, cod, halibut, tuna, salmon, herring |creams, chocolate, Swiss rolls. |

Healthy Eating

A growing trend towards healthier foods is being introduced in catering operations. Many menus offered by both hotel- and stand-alone restaurants highlight those dishes which have been specially prepared for vegetarians or for customers who love healthy eating. The switch to a more healthy style of eating started about 15 years ago and was supported by the variety of low-fat food products available at supermarkets.

Healthy eating refers to a well balanced diet providing adequate amounts of the various nutrients. Since nutrients are present in each group of foods, a healthy diet menu is obtained by choosing a variety of items from different groups. Healthful low-fat meals may be interesting, satisfying and tasty. They are dishes whose fat has been replaced with robust flavours and savoury ingredients. Major changes which have occurred in the preparation of healthy eating range from appetisers to desserts and place emphasis on the following:

more vegetables which are naturally low in fat and offer a wealth of vitamins, minerals and fibre;

more fruits which have nutritional benefits similar to vegetables;

whole grains and pasta which are naturally lean sources of essential complex carbohydrates. Rice, macaroni, spaghetti and noodles have increased in popularity.

wholemeal bread which contains more vitamins, minerals and fibre.

beans, peas and lentils which are a low-fat protein source.

low-fat dairy products;

skinless grilled or roast chicken;

grilled lean meat;

fish and shellfish which are low in fat and high in protein;

“lean” sauces which have become a flavour booster to low-fat foods, especially grilled fish, vegetables and shellfish;

seasonings, zesty ingredients, assorted fresh and dried herbs and spices, snack foods (pretzels, rice cakes, vegetable soup, chicken noodle soup, whole-grain crackers, breadsticks, wafer-style cookies).

These types of menus cut back on foods that are high in fat. The new password seems to be “Low in fat, high in flavour”.

Here follows an example of the healthy breakfast menu offered by Sheraton Park Towers Hotel, London:

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Adjectives describing food

Spicy, peppery, rich, creamy, fattening, strong, mild

|Opposites: |raw |cooked |

| |hot |cold |

| |light |heavy |

| |sweet |bitter-sour |

| |tasty |tasteless |

| |juicy |dry |

| |fresh |stale |

| |soft-tender |hard |

| |salty |insipid |

| |crisp-y |flabby |

| |undercooked |overcooked |

Phrases describing dishes

It’s….

It’s a sort of……….

It contains……

It’s made of…………

It’s cooked in…….

It’s filled with…..

It’s flavoured with……

It’s served with…..

It’s stuffed with…….

It’s sprinkled with……

It’s grilled …

It’s seasoned with…….

It comes with …….

It takes 20 minutes cooking time

1. Match the items on the left with the appropriate completion on the right

|Milk, yoghurt and cheese |are found in the grains, the legumes and the tubers |

|Bread and pasta |are calcium rich foods |

|Grains and grain products |are a valuable source of vitamin C |

|Vegetables |affect the development of bones and teeth |

|Citrus fruits |are rich in carbohydrates, protein, fiber, vitamins and minerals |

|Carbohydrates |are needed for the body’s energy |

|Minerals |meet the body’s need for minerals, vitamins and cellulose |

|Starches |are a model of low fat, high fiber diet |

|1 |2 |3 |4 |5 |6 |7 |8 |

| | | | | | | | |

2. Check the food items of this dish and say which nutrients it contains.

|[pic] |Food items: |

| |turkey breast tenderloins (1 pound) |

| |chopped onion (1/4 cup) |

| |bread crumb (1/2 cup) |

| |spaghetti (16 ounces) |

| |cherry tomatoes |

| |2 tablespoons oil |

| | |

| |Nutrients: |

| |.................................................... |

| |.................................................... |

| |.................................................... |

| |.................................................... |

| |.................................................... |

| |.................................................... |

3. Write the names and the nutrients associated with the following food items:

|[pic] |name: |[pic] |name: |

| |.............................. | |.............................. |

| | | | |

| |nutrients: | |nutrients: |

| |.............................. | |.............................. |

| |.............................. | |.............................. |

| | | | |

|[pic] |name: |[pic] |name: |

| |.............................. | |.............................. |

| | | | |

| |nutrients: | |nutrients: |

| |.............................. | |.............................. |

| |.............................. | |.............................. |

| | | | |

|[pic] |name: |[pic] |name: |

| |.............................. | |.............................. |

| | | | |

| |nutrients: | |nutrients: |

| |.............................. | |.............................. |

| |.............................. | |.............................. |

| | | | |

|[pic] |name: |[pic] |name: |

| |.............................. | |.............................. |

| | | | |

| |nutrients: | |nutrients: |

| |.............................. | |.............................. |

| |.............................. | |.............................. |

4. Refer to the description on the left column and cross the correct box on the right.

|This yellow-skinned edible fruit is rich in carbohydrates and is a |lemon ( |

|source of vitamins A and C and the minerals potassium and phosphorus. |banana ( |

|Their color ranges from various shades of red to yellow or green. They|apples ( |

|supply appreciable quantities of carbohydrates, calcium and vitamin A.|cherries ( |

|Small, soft round fruits, red or black when ripe. They have a low |cherries ( |

|caloric power, and contribute carbohydrates, calcium and vitamin-A. |oranges ( |

|A juicy citrus fruit which supplies large amount of vitamin C. |lemon ( |

| |kaki ( |

|A small green vegetable usually cooked when eaten. It’s rich in |courgette ( |

|calcium |lettuce ( |

|A vegetable whose edible flower stalks contain minerals (calcium, |cauliflower ( |

|iron) and vitamins. |fennel ( |

5. Label the following legumes:

|[pic] |[pic] |[pic] |[pic] |

| | | | |

|1 ........................... |2 ............................ |3 ............................ |4 ............................ |

6. Insert the following food items in the correct column:

spinach, sugar, rye, corn flakes, peas, cod, yolk, yogurt, butter, lamb, noodles, tomatoes, peaches, strawberries, lentils, ice cream, milkshake, potatoes, chicken, sole, tuna, rice, chestnuts, butter, grapefruit, cake, veal, liver, bread sticks, broccoli, eggs.

|Milk & Dairy |Meat-Fish-Poultry |Legumes & Cereals |Bread & Pasta |Fruit |Vegetables |

| | | | | | |

| | | | | | |

| | | | | | |

| | | | | | |

| | | | | | |

| | | | | | |

Reading Passage

Nutritional Value of Beans

When separating the “haves” from the “have-nots” on the playing field of nutrition, beans line up as all-stars. Beans are grouped in the U.S. Department of Agriculture’s Food Guide Pyramid with high protein foods such as meat, eggs, poultry and fish and with vitamin-rich vegetables. The double dose of nutrition packed into beans makes them perfect in the daily diet. They are high in complex carbohydrates, protein and dietary fiber, low in fat and sodium, and completely cholesterol-free. As little as a half-cup of beans added to your daily diet can be very helpful in reaching important nutrition goals.

Protein is an essential nutrient that our bodies need daily for sound bones, muscles, healthy cartilage, blood, skin and the proper working of lymph glands. A constant supply of protein keeps your body working at peak efficiency. Beans, an excellent sourse of protein, are an ideal alternative to animal proteins. As members of the vegetal group, beans are chock-full of vitamins and minerals. Beans are rich natural sources of the B-complex vitamins - thiamin, pyridoxine, niacin and folc acid. These vitamins trigger the processes that release energy from carbohydrate foods, help absorb and metabolize proteins, help in the formation of red blood cells, and keep the digestive and nervous systems healthy. In addition to being high in protein, vitamins and minerals, beans are loaded with complex carbohydrates - a natural, healthy source of energy just right for today’s active lifestyles Gram for gram, complex carbohydrates provide half the calories of fat. They are absorbed more slowly than simple carbohydrates, such as table sugar and candy, so beans satisfy hunger for longer periods of time. Beans are also one of the best sources of dietary fiber, containing both insoluble and soluble fiber. Insoluble fiber, generally thought of as “roughage” that moves quickly through the digestive system, is important in our diets because it helps promote a healthy digestive tract and can reduce the risk of some types of cancer. During digestion, soluble fiber forms a gel-like substance which helps the body handle fats, cholesterol and carbohydrates. Soluble fiber plays a role in helping to lower blood cholesterol levels, one of the main risk factors for the development of cardiovascular disease. Since fiber-rich foods are filling, beans also are helpful in weight control.

Beans should be added gradually to the diet with a goal of one half-cup serving per day. Consumption should be increased over a four-to eight-week period, even if it’s a bite or two per day. Adding beans to soup or salad is a good way to gradually increase consumption. It is also important to drink plenty of liquids as you can increase your bean intake because fluids aid in the digestion of beans. The key is to continue eating beans once the body’s system is adjusted to them.

7. Refer to Nutritional Value of Beans and answer the following questions:

1. Which foods are beans grouped with in the USDA Food Guide Pyramid?

1. Which food items are high protein foods?

2. Which nutrients do beans have?

3. Which parts of our body does protein affect?

4. Which functions do bean vitamins perform?

5. What do bean carbohydrates provide?

6. Why is insoluble fiber important in our diet?

7. How is soluble fiber helpful to our body?

8. What should your bean daily serving be like?

9. Which way can you follow to increase bean consumption in the diet?

8. Refer to Nutritional Value of Beans and give the Italian equivalents to the following phrases:

1. They are high in... low in...

1. As little as a half-cup of beans

2. ... keeps your body working at peak efficiency

3. beans are chock-full of...

4. In addition to being...

5. dietary fiber

6. ...helps the body handle fats

7. to lower blood cholesterol level

8. Fiber-rich foods are filling

9. over a four-to eight-week period

10. you can increase your bean intake

11. once the body’s system is adjusted to them

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Fats Carbohydrates Proteins Minerals Vitamins

Body-protecting foods

Body-building foods

Energy-giving foods

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