Nutrition New Syllabus PDF

SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL NUTRITION Food & Nutrition 1.1 Introduction To Food & Nutrition Food is any substance, liquid or solid, which provides the body with materials;  For heat & energy.  For gr...

SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL NUTRITION Food & Nutrition 1.1 Introduction To Food & Nutrition Food is any substance, liquid or solid, which provides the body with materials;  For heat & energy.  For growth & repair,  To regulate the body processes Nutrients are the chemical substances found in food which are used by the body for growth & health. They are; Proteins Vitamins Fats Minerals Carbohydrates Water Food is the carrier of Nutrients. Most foods contain several nutrients; protein, carbohydrate, fat, fiber, vitamins & minerals. Ex: 100 g of boiled rice contains about; 27 g of carbohydrates, 3 g of proteins, 0.08 g of minerals, 0.004 g of vitamins A few foods contain only one nutrient (Ex. Sugar). For the body to obtain the maximum benefit from food it is essential that everyone concerned with the buying, storage, cooking and serving of food and the compiling of menus should have some knowledge of nutrition. A poor diet is a risk factor for the major chronic diseases that are the leading causes of adult death: heart diseases, stoke, hypertension, diabetes and some form of cancer. Nutrition is the science studying on nutrients of food, ingestion, digestion, absorption & utilization of nutrients by the body. The health aspects of food are also taking into consideration under nutrition. Essential Nutrients are substances required for normal growth & health that cannot be produced in sufficient amount by the body, as a result they must be obtained in diet. Non Essential Nutrients are substances required for normal growth & health that can be manufactured by the body. Other substances: Anti-nutrients are substances in foods that are natural poisons or toxins (Ex: the poisons in cassava) Food additives are chemicals which are added to some foods such as canned foods, bottled drinks, sausages, etc. Additives may improve the taste or appearance of the food, improve its nutritive value, and make the food keep longer. 1 Digestion & Absorption of Nutrients Digestion This is the breaking down of the food & takes place, (a) in the mouth, where food is mixed with saliva, and starch is broken down by the action of an enzyme in saliva (b) in the stomach, where the food is mixed & gastric juices are added, and proteins are broken down (c) in the small intestine, where proteins, fats & carbohydrates are broken down further and additional juices are added The digestive tract Absorption To enable the body to benefit from food it must be absorbed into the blood-stream; this absorption occurs after the food has been broken down; the product then passes through the walls of the digestive tract into the blood-stream. This occurs in: (a) the stomach where simple substances are formed as a result of digestion and pass through the stomach lining into the blood stream (b) in the small intestine where more of the absorption of nutrients takes place due to a further breakdown of the food (c) in the large intestine, where water is re-absorbed from the waste For the body to obtain the full benefit from foods it should be remembered that to stimulate the flow of saliva and gastric juices food must smell, look and taste attractive. 2 SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL NUTRITION 1.2. Main Functions of Nutrients Macronutrients – Nutrients which are required in large amounts are called macro nutrients. Those are carbohydrates, proteins & fats. Micronutrients – Vitamins & minerals are needed in very small amounts but essential for body regulation. Macro and micronutrient function together biochemically as a team. The body uses nutrients:  to build the body, produce fluids, and repair tissues  to produce energy so that the body can keep alive and warm and so that it can move and grow  to help chemical processes (regulation)  to protect the body from disease Why we need nutrients A person, who weighs 50kg, consists of about 31kg of water, 9gk protein, 7kg fat & 3kg minerals (62% water, 18% protein, 14% fat, 6% Minerals).  Carbohydrates, fats, proteins  Energy  Proteins, minerals, water  Growth & repair  Vitamins, minerals, water  Regulation of body processes Proteins Protein is an essential part of all living mater and body cannot make protein from carbohydrate or fat. All plant & animal contain protein, but the proteins in each of them are different. The building block of protein is amino acids. There are 20 known amino acids, 9 amino acids out of 20 are called essential amino acids which cannot be synthesized in he body. Some good sources of protein: Milk, fish, meat, eggs, cheese, soya beans, groundnut, & peas (legumes) Complete & incomplete proteins Most animal proteins contain the same proportion of each essential amino acid as human proteins. Because of this protein in eggs, meat, and fish are sometimes called complete proteins. They are also known as high-quality proteins. Proteins in plants often contain much smaller amounts of one or more essential amino acids than animal and human proteins. Proteins from plant are sometimes called incomplete proteins or low-quality proteins. How the body uses protein  to build new tissues & fluids  to replace loss amino acids – during illnesses loss of amino acids is faster  to help the cells to work – enzymes  to protect the body against infections – antibodies  as fuel for energy – 4 calories/gram 3 People need less protein if they eat complete proteins than if they eat incomplete proteins. Ex: the daily protein needs of 1-3 year old children are about 14 g if they eat complete protein and about 23 g if they eat incomplete protein. The amount of fiber in a meal affects the amount of protein which is digested & absorbed. If a meal contains less fiber, more protein is digested. If a meal contains more fiber, less protein is digested. Carbohydrates There are three main kinds of carbohydrates.  Starch  Sugar  Fiber Sugar There are several kinds of sugars found in different foods. Such as; Glucose – found in the blood of animals, in fruits & honey Fructose – found in fruit, honey & cane sugar Sucrose – found in beet & sugar cane Lactose – found in milk Maltose – produce naturally during the germination of the seeds Sugars are the simplest form of carbohydrate and end –products of the digestion of carbohydrates. They are absorbed in the form of glucose and used to produce heat & en energy. Starch Starches are main sort of carbohydrate in; Cereals – rice, maize, wheat and cereal products Starchy roots – cassava, yams & potato Starchy fruits – unripe bananas, apples, cooking pears Vegetables – peas, beans When starch is digested in the gut, it breaks down into glucose. The glucose is absorbed into the blood and goes to the cells to provide energy. Starch is stored in starch grains inside plant cells. When a starchy food is boiled the starch grains absorb water. They swell up and may break. This makes the starch easier to digest. It may make the food swell up. Cooked starchy foods which contain a lot of water are called bulky foods. How the body uses starches & sugars  As fuel for energy. We burn most of the starch & sugar that we eat to make energy  4calories/gram  To build fat stores. The body cannot store much carbohydrate. If we eat more starch or sugar than we need for energy, the body changes it into storage fat.  To build cells. A little carbohydrate is used to build cells. 4 Fats “Fat” is often used as the general term for a class of nutrients called lipids. Fat is made of fatty acid and glycerol. Lipids include both fats & oils. Lipids which are hard at room temperatures (butter, cooking fat, ghee) are called fats while lipids which are in liquid form at room temperature are called oils. Fats provide more calories per gram (9 kilocalories/gram) than any other nutrient. Sources of lipids  Plant origin – coconut oil, palm oil, maize oil, olive oil, sesame oil, margarine, soya bean, ground nut, almond, avocado,(vegetables & fruits contain very little fat, but nuts have a considerable amount)  Animal origin – butter, ghee, fatty fish, meat, chicken, milk, cheese, suet (certain fish such as herrings, mackerel, salmon, sardines, contain fat in the flesh. Other fish such as cod and halibut contain the oil in the liver). How the body uses fat  Fat is a concentrated source of energy. One gram of fat provides twice much energy as one gram carbohydrate. 9 kilocalories/gram  Fat is an important energy store of body in the form of triglycerides.  Essential fatty acids help body processes  Fat helps absorption & transportation of fat soluble vitamins (vitamin A)  Essential fatty acids needed to build cells  Pad & support organs  Fat helps keep skin & hair healthy & supple Fats are composed of glycerol to which is attached three fatty acids. Fats differ because of the fatty acids from which they are derived. These fatty acids affect the texture & flavor of the fat. Ex: butyric acid in butter, stearic acid in solid fat, such as beef suet, oleic acid in most oils. To be useful to the body, fats have to be broken down into glycerol and fatty acids so that they can be absorbed. The food value of different kind of fat is similar, although some animal fats contain vitamins A & D. Fats should be eaten with other foods such as bread, potatoes, etc, as they can then be more easily digested and utilized in the body. 5 Saturated and unsaturated fatty acids Fats which contain a large proportion of saturated fatty acids are usually harder at cool temperatures than fats which contain a small proportion. Fats which contain a large portion of saturated fatty acids are called “saturated fats”.  the meat & milk of animals  coconut Fats which contain a large portion of unsaturated fatty acids are called “unsaturated fats”. Saturated fats have a high melting point. Monosaturated fats are found primarily in plant foods very as to density & melting point (olive oil, peanut oil, & avocados). Polyunsaturated fats are found mostly in plant foods, are liquid at room temperature, and have a low melting point (soya oil, corn oil, & safflower oil). Normally vegetable oil contain mono or polyunsaturates.  Fish – omega 3 fatty acids  oil seeds such as sesame, olive & sunflower  cereals and legumes (maize oil & groundnut oil) Cis & trans fatty acids Unsaturated fatty acids which occur naturally are “cis” fatty acids. When unsaturated fats are processed the cis fatty acids may turn to “trans” fatty acids if they were saturated. The body cannot use “trans” fatty acids and it creates health problems too. Water Water is required for; All body fluids Digestion Absorption Metabolism Excretion Secretion Regulation of body temperature Drinks and foods are the main sources of water. 6 Vitamins Vitamins are chemical compounds that the body needs in small amounts to help it function properly. The important vitamins, their functions & sources of vitamins are given in the table below. Vitami Function Sources n A Prevent infections, prevent Animal milk, liver, kidneys, eggs, butter, tissue damage, keep eye & ghee – Retinol skin healthy, Yellow or green fruits & vegetables, dark green leaves – beta carotene D Keep bone & teeth healthy Sunlight, fish liver oil, oily fish, egg yolk, dairy products E Act as an antioxidant Foods containing polyunsaturated vegetable oils and wholegrain cereals K Help to blood clotting Intestine resident bacteria, green vegetables & milk B Keep the nervous system in Yeast, whole meal bread, cheese, eggs, complex good condition, help for liver, kidney energy production using carbohydrates, encourage the growth of body Folate Helps the body to grow, make Fish, beans, liver, kidney, fresh red blood cells, (need to eat vegetables, dark green leaves & every day) groundnuts C Need for absorption of Most of fruits, tomato, lime, orange etc. calcium & iron, healing of (lost during cooking, when store foods for cuts & wounds, prevent mouth too long and by cutting vegetables into & gum infections small pieces) Minerals There are over 20 minerals known to be necessary to body biochemical functions. Imbalance in concentration of minerals that interact can lead to serious consequences in the body. Mineral Function Sources Iron make haemoglobin for red blood Blood & meat of animals & fish – cells, build new tissues, help haem iron other cells to function Egg, milk, legumes, cereals – non haem iron Iodine Production of thyroid hormone, Foods from the sea, iodized salt development & function of the brain and nervous system, growth of children Calcium Keep teeth & bone healthy, Milk, small fish, beans, peas, finger millet, dark green leaves, hard water Sodium & Ion balance in body fluids Natural foods- fruits, vegetables, Potassium spinach, legumes, pumpkin Zinc Help to children grow & develop Meat, chicken, fish, legumes, 7  SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL normally wholegrain cereals NUTRITION 1.3. The Cooking Of Nutrients Carbohydrates Starch Uncooked starch is not digestible. Foods containing starch have cells with starch granules, covered with a cellulose wall which breaks down when heated or made moist. Two types of starch molecules are found, they are amylose and amylopectin. Amylopectin is a highly branched molecule than amylose. Starches vary in the proportion of these two molecules resulting differences in finished products; texture, stability, translucency, & viscosity. When browned (crust of bread, toast, roasted potato) the starch forms dextrin and these taste sweeter. On heating with liquid starch granule swell, absorb liquid and also escape the content thus thickening the product. This process is known as gelatinization and starch is used as thickening agent. A sauce will begin to thicken at about 35oC (95oF), and gelatinization occur at about 96oC (205oF). Once maximum viscosity is reached, the sauce will start to thinning, as will rapid stirring – especially with wire whisk. Overcooking it simply breaks the granule network into small pieces, and liquid becomes more evident. In the absence of heat the molecular motion will decrease, the liquid is trapped in the solids. As a sauce cools from cooking to serving and eating temperature it will gradually become thicker. Since flour contains protein, more is necessary to achieve thickening than with corn starch, which is pure starch. Flour-based sauces will look opaque, whereas corn and root starches give translucent finish. When a starch-thickened sauce is frozen and thawed later, it separates and becomes watery. This process is called retrogradation. In such cases pre-gelatinized starch can be used to prevent retrogradation. Sugar When sugar is heated it melts and with further heating loses water, gradually turning brown, dark brown and then black. This is known as caramelisation of sugar. Sweeteners also come in the form of syrups, which include honey, molasses & corn syrup. Because of long chains, which do not cause a very sweet taste, corn syrup can be used freely without the product becoming overly sweet. In confectionary & baking, its viscous nature prevents crystallization. It is also gives foods texture and helps prevent moisture loss. All sugars help retain moisture thus extend shelf life. Sugar helps retain elasticity in gluten, protein component primarily found in wheat flour. Too much sugar in a starch-thickened base will result in a thin, watery product, because sugar absorbs more water than starch granule. 8 Protein On being heated, the different proteins in foods set or coagulated at different temperatures; above these temperatures shrinkage occurs, this is particularly noticeable in grilling or roasting meat. Moderately cooked protein is the most easy to digest. Ex: a lightly cooked egg is more easily digested than raw egg or a hard-boiled egg. Denaturation (protein chain uncoil & change shape) is caused mainly by heat and acidity, although salt can contribute to the reaction. Coagulation is the most obvious change in protein, for example, when a poached egg or baked custard becomes firm forming a visible mass. If coagulation continuous, a gel result. The coagulation of protein occurs at temperatures from approximately 16 to 21 oC (62 to 70oC). if temperatures are too hot or the cooking time is prolonged, liquid may be released from the coagulated protein (syneresis). Pockmark for example, is a sign of over cooking of protein containing foods. Coagulation of protein (gluten) in baked products gives the rigid structure for product such as bread. Since this structure is not desirable in cakes, wheat flour is mixed with corn flour, will result in a smoother texture. Collagen is the white fibrous protein and a major connective tissue in meat. Heat applied in cooking cause contraction of collagen fibers. Hot, moist environment for a long causes collagen break down into gelatin. Elastin is the yellow colored protein in meat, which does not break down in the presence of heat. Tenderizing is one way to reduce the amount of connective tissue in some cuts of meat. Mincing or grinding cut the connective fibers to reduce the effect of connective tissue. Enzyme such as papain is also used to reduce the fibrous effect of meat. This is only a surface tenderizer. Acids & salt are also tenderizers. (ex; vinegar). Aging is also a way of tenderizing. Protein together with fat inhibits the formation of ice & sugar crystals (ex; ice cream & sherbet). Fat Smoke point temperatures of cooking fats differ. Fats can be heated to relatively high temperatures to cook food quickly. The best oils to use for frying are those with smoke point of 211oC (400oF). Animal fats, olive oil and hydrogenated vegetable oil are having relatively lower smoke point about 190oC (375oF).the progression from smoke point to flash point and fire point can occur rapidly. Combination of vegetable oils in products, presence of foreign properties (batter), temperature to which oil is heated, presence of salt, number of times oil is used, length of time oil is heated , and storage of oil (exposure to oxygen, light, temperature) will decrease the smoke point. 9 Oils such as palm oil & coconut oil are used mainly for deep frying due to their resistance to oxidation. Oils such as soybean oil and sunflower oil are used for salad dressings or shallow frying since they have a greater tendency to oxidation. Over heating oil can destroy its health benefits and even turn the healthy oils into trans fatty acids. Omega-3 should be served cold. Over heating will result formation of free radicals which are carcinogenic. Mono & polyunsaturates are more vulnerable to oxidation. Because of that reuse of heated oil should not be practiced. Remove food particles from used deep-frying oil by straining it through a coffee filter, or a sieve or funnel lined with a double layer of cheesecloth. Cover, tightly seal and refrigerate strained oil; it can then be used one more time. Vitamins Vitamin A and D withstand cooking temperatures, and they are not lost in the cooking liquid. Vitamin B1 (thiamine) can be destroyed by high temperatures. It is soluble in water and can be lost in cooking. Vitamin B12 (riboflavin) is not destroyed easily by heat but bright sun light can break it down. Vitamin C is water soluble and can loss with water and also susceptible to heat. Because of that fruits & vegetables should be minimally cooked. Minerals Here is a possibility of some minerals being lost in the cooking liquor, such as salt, but not to calcium or iron compounds. Iron may be acquired from foods cooked in iron utensils. The iron in food is not affected by cooking. Cooking foods in hard water may very slightly increase the amount of calcium in food. 10 SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL NUTRITION 1.4. Food Requirements How to measure energy We measure energy in calories in the same way that we measure weight in grams. In nutrition, we use kilocalories (like kilocalories), kcal or kilojoules,kJ. The amount of energy which nutrients give as follows; Fat 9 cal/g ; 36 kJ Starch 4 cal/g ; 16 kJ Sugar 4 cal/g ; 16 kJ Protein 4 cal/g ; 16 kJ Ex: one spoonful of fat (10g90cal) gives more energy than two spoonful of sugar (20g80cal). Foods having a high fat content will have a high energy value; those contain a lot of water, a low energy value. Young and active people require a different amount of food. Men require more calories than women, big men & women require more than small men and women, and people engaged on energetic work require more calories than those with sedentary occupations. Knowing the quantities of the energy yielding substances in a food, you can estimate the total energy in that food using these kcal values. Foe example; (a) if a banana milk shake contains 45g of carbohydrates, 7g of protein, and 10g of fat, it would provide 298kcal. (b) if a banana flavored rum drink contains 10g of carbohydrate, 1g of fat and 15g of alcohol, it would provide 158kcal. The nutritional status for a particular nutrient is desirable when body tissue have enough of the nutrient to support normal metabolic reactions as well as surplus stores that can be mobilized in times of increased need. Recommended Dietary Allowance (RDA) RDA is the recommended intakes of nutrients that meet the needs of almost all healthy people of similar age and gender. RDA represents the nutrient needs of groups, not of individuals. RDAs are established for specific gender and age categories. For example; Classification Energy Protein Calcium Iron Vitamin C (kcal) (g) (mg) (mg) (mg) Female (65kg) 2300 49 400-500 14-28 30 Male (75kg) 2900 56 400-500 5-9 30 (Protein requirement of person = 0.8 x body weight) 11 Recommended percentage of dietary macronutrient Basal Metabolism Basal metabolic rate (BMR) is the amount of energy expanded while at rest in a neutrally temperate environment, in the post-absorptive state (meaning that the digestive system is inactive, which requires about twelve hours of fasting in humans). The release of energy in this state is sufficient only for the functioning of the vital organs, such as the heart, lungs, brain and the rest of the nervous system, liver, kidneys, sex organs, muscles and skin. BMR decreases with age and with the loss of lean body mass. The energy requirement of basal metabolism is approximately 1700kcal. In addition to energy required by basal metabolism, energy is required for other activities also. The approximate energy requirements per day for the following examples are; Clerk 2000kcal Carpenter 3000kcal The table bellow indicates the recommended daily allowance of calories to provide a healthy diet; Age & Sex Calories Boy 11-14 y 2750 Woman 20+ 2500 Man 20+ 3000 12  SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL NUTRITION 1.5. Value Of Food In The Diet Milk The exact composition of raw milk varies by species, but it contains significant amounts of saturated fat, protein and calcium as well as vitamin A, D, & B. Most humans lose the ability to fully digest milk after childhood (that is, they become lactose intolerant). The sugar lactose is found only in milk, some times human loose the ability of digesting them. Milk contains, on average, 3.4% protein, 3.6% fat, and 4.6% lactose, 0.7% minerals and supplies 66 kcal of energy per 100 grams. Eggs Eggs add protein to one's diet, as well as various nutrients. Chicken eggs are the most commonly eaten eggs. They supply all essential amino acids for humans, and provide several vitamins and minerals, including vitamin A, riboflavin, folic acid, vitamin B6, vitamin B12, choline, iron, calcium, phosphorus and potassium. They are also an inexpensive single-food source of protein. Vitamin A, D and E are in the egg yolk. The egg is one of the few foods which naturally contain Vitamin D. A large egg yolk contains approximately 60 Calories (250 kilojoules); the egg white contains about 15 Calories (60 kilojoules). A large yolk contains more than two-thirds of the recommended daily intake of 300 mg of cholesterol Fish The Nutritional Value of Fish Salt-water fish are a superior source of nutrients, which are vital to growth and good health. Fish yield high amounts of proteins, vitamins, minerals and polyunsaturated fats. Fish proteins are complete. A four-ounce serving can contain from thirty to fifty percent of the body's daily requirement of protein. Fish are also a valuable source of vitamins A and D. All fish contain several of the B complex vitamins. Some of the minerals supplied by salt-water fish are phosphorous, copper, iron, calcium and iodine. Fatty fish is the main source of omega 3 fatty acids. Meat All muscle tissue is very high in protein, containing all of the essential amino acids, and in most cases is a good source of zinc, vitamin B12, selenium, phosphorus, niacin, vitamin B6, iron and riboflavin. However, meat tends to be high in fat (red meat in particular), low in carbohydrates, and contains no fiber. The fat content of meat can vary widely depending on the species and breed of animal, the way in which the animal was raised, including what it was fed, the anatomical part of the body, and the methods of butchering and cooking. Wild animals such as deer are typically leaner than farm animals, leading those concerned about fat content to choose game such as venison. Fruits Fruits are generally high in fiber, water and vitamin C. Fruits also contain various phytochemicals that do not yet have an RDA/RDI listing under most nutritional factsheets, and which research indicates are required for proper long-term cellular 13 health and disease prevention. Regular consumption of fruit is associated with reduced risks of cancer, cardiovascular disease, stroke, Alzheimer disease, cataracts, and some of the functional declines associated with aging. Vegetables Sweet potatoes- Nutritionally, the sweet potato is a good source of vitamin C and provides dietary fibre as well as folic acid, vitamin E and potassium when eaten with the skin on. It also contains some calcium, iron and phosphorous. The orange and yellow varieties are an excellent source of vitamin A. Tomatoes- Tomatoes are an excellent source of vitamin C, a useful source of vitamin E with some vitamin A and dietary fibre. Turnips- Turnips are an excellent source of vitamin C and a good source of dietary fibre. Spinach - Spinach does have a high iron content, but it is most useful as a source of vitamin C and vitamin A. It is also a good source of potassium and is, contrary to common belief, quite low in sodium. By comparison, silverbeet, which is often mistakenly called `spinach', has much less vitamin A and does have a reasonably high level of sodium. It also has a much stronger flavour and coarser texture than true English spinach. Pumpkin- Although some varieties have been valued for their nutritious seeds, the flesh of pumpkin is also a rich source of carotene which is converted to vitamin A in the body. They are also good sources of vitamin C and provide dietary fibre and potassium, as well as some iron. Eggplant -Eggplant provides small quantities of many vitamins and minerals as well as dietary fibre. It has no fat and is low in kilojoules. Leeks- Leeks are a good source of vitamin C and provide dietary fibre and small amounts of a number of other vitamins and minerals. Lettuce- Lettuce provides some potassium, carotene (in the dark green outer leaves), dietary fibre and small quantities of other minerals and vitamins. It has very few kilojoules. Onions- Onions are a good source of vitamin C, B3 (niacin) and calcium. Cereals Cereals contain from 60% to 80% carbohydrate in the form of starch and therefore energy foods. They also contain 7-13% protein, depending on the type of cereal, and 1-8% fat. The vitamin B is also found in cereals. Milling will affect the nutrient content of cereal. 14 Purchasing, storing & preparing foods The nutrition quality of the food that ends up on the consumer’s plate is affected by every stage at which it is handled, from farm to kitchen. If a food product is not fresh when it is purchased or deteriorates as a result of storage and handling procedures, its nutritional quality will be poor. Nutritional quality is only as good as the quality of the food product. More nutrients may be lost when the food is stored, prepared and served. Both physical (trimming vegetables) and chemical (expose to water, light, and temperature) losses may occur. Freshly harvested fruits and vegetable contain more vitamins than stored ones. Examples of nutrition loss during storing, and preparing foods; (a) Canned fruit & vegetables – prolonged storage and higher storage temperature deteriorate nutrient. Liquid contain 1/3 of the nutrient content. (b) Frozen foods - quality & nutrient content will deteriorate at temperature higher than -18oC. Freezing & thawing also affect nutrient content. (c) Fats & oil - light speeds rancidity in fats & oils. (d) Fruits & vegetables – trimming and washing will reduce nutrient content (e) Cereals / grains – milling, washing and draining water will reduce nutrient content Washing rice before cooking looses 25% thiamin in white rice, 10% in red rice. A general rule is the lower the temperature and the shorter the cooking period, the less nutrient loss.  Three major factors in preserving nutrients when cooking vegetables includes; little surface area, short time period and as little water as necessary. Smaller the amount of water, more vitamin B & vitamin C will remain.  Stir-frying & steaming are good methods to preserve nutrients.  Baking root vegetables in their skin result in significant increase in vitamin retention. 15  SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL NUTRITION 2.1. Balanced Diet and Meal Planning Tools A diet is considered "balanced" when all food groups are represented in healthy proportions or percentages. This means following the recommended daily allowances for micronutrients and for macronutrients—fats, carbohydrates, and proteins. A. The food guide pyramid The Food Guide Pyramid is an outline of what to eat each day based on the Dietary Guidelines. It's not a rigid prescription but a general guide that lets you choose a healthful diet that's right for you. The Pyramid calls for eating a variety of foods to get the nutrients you need and at the same time the right amount of calories to maintain healthy weight. Food groups according to the food guide pyramid; How many servings of each per day should you eat? Foods Women - Children Teenage girls - Active Teenage boys - - Elderly Females - Males Active Males Calorie level Aprox. 1,600 Aprox. 2,200 Aprox. 2,800 Milk Products 2 to 4 2 to 4 2 to 4 Group Meat Group 2 2 3 Vegetable 3 4 5 Group Fruit Group 2 3 4 Bread and 6 9 11 Cereals Total Fat in 36 to 53 49 to 73 62 to 93 grams How much is one serving? Milk products group: 1 cup about 8 oz. of milk or yogurt 2 slices of cheese, 1/8" thick (1½ oz.) 2 cups of cottage cheese 1½ cups of ice milk, ice cream or frozen yogurt Meat group: 2 oz. to 3 oz. of cooked lean meat, poultry, fish 2 eggs 7 oz. tofu 1 cup cooked legumes or dried beans or peas 4 tablespoons peanut butter 1/2 cup nuts or seeds Vegetables: 1/2 cup cooked vegetables 1/2 cup raw chopped vegetables 16 1 cup raw leafy vegetables 1/2 to 3/4 cup vegetable juice Fruits: 1 whole medium fruit (about 1 cup) 1/4 cup dried fruit 1/2 cup canned fruit 1/2 to 3/4 cup fruit juice Bread and Cereals: 1 slice bread 1 medium muffin 1/2 hot dog bun or hamburger bun 1/2 bagel or english muffin 4 small crackers 1 tortilla 1 cup cold cereal 1/2 cup cooked cereal 1/2 cup rice 1/2 cup pasta B. Food exchange list Four food group plan, based on foods we consume. It included a milk group, a meat group, a fruit & vegetable group and breads & cereals group. The entire plan was designed to provide about 1200 to 1400kcal per day. Starch list -15g carbohydrate per serving 1 small baked potato, ½ English muffin, 2 pancakes 4” diameter, 1/3 cup cooked rice Vegetable list – 5g carbohydrate per serving ½ cup vegetable juices, ½ cooked vegetables, 1 cup raw vegetables Fruit list – 15g carbohydrate per serving ½ fresh fruit, ¼ cup dried fruit, ½ cup fruit juice, 1 orange, 1 ½ cup water melon Milk list - 12carbohydrate per serving 1 cup milk, ½ cup plain low-fat yogurt Other carbohydrates list – 15g carbohydrate per serving 2 inch squire typical slice of cake, 2 small cookies, ½ cup ice cream, ½ cup sherbet Reducing calories in the kitchen What can food professional do to help customers watch calories? Offer low-calorie alternatives on the menu, and be prepared to back them with calculations if asked. A 17 daily low-calorie special can be a marketing tool. When menu decisions have been made, there are things that can be done in the kitchen. Food professionals can provide variety on plates and strive for attractive presentations. These approaches help offset reduced portion size and eliminate the small or odd sized plates. Keep in mind the carbohydrate, fat and protein ratio on the plate in terms of their relative calorie contribution. Most animal protein and regular dairy products contain fat calories. Therefore become creative with low-fat substitutions. Increase the vegetable and starch to meat ratio on the plate. Avoid the use of liaisons such as roux, egg yolk and butter while using bit of corn starch or increasing gelatin content. The food guide pyramid and the food exchange list will be more helpful when preparing low-calorie dishes. Culinary students learn the importance of weighing ingredients. Calculating nutrients can be excellent training also. This will help to prepare nutritionally balanced meals. When planning menu, reducing the amount of fat, cholesterol, saturated fatty acids and salt in the diet should be taken into consideration. Providing nutritionally balanced meals Food service personnel are not responsible for client’s selections in terms of a balanced diet. But it is their responsibility to offer a choice of items that make it possible for customers to eat a healthful meal. As commercial foodservice provides for a greater percentage of the public’s nutritional needs, the professional’s responsibility with respect to the menu increases. 18  SRI LANKA INSTITUTE OF TOURISM AND HOTEL MANAGEMENT CERTIFICATE LEVEL NUTRITION 2.4. Dietary Fiber Dietary fiber — found mainly in fruits, vegetables, whole grains and legumes — is probably best known for its ability to prevent or relieve constipation. But fiber can provide other health benefits as well, such as lowering the risk of diabetes and heart disease. Dietary fiber, also known as roughage or bulk, includes all parts of plant foods that your body can't digest or absorb. Unlike other food components such as fats, proteins or carbohydrates — which your body breaks down and absorbs — fiber isn't digested by your body. Therefore, it passes virtually unchanged through your stomach and small intestine and into your colon. Fiber is often classified into two categories: those that don't dissolve in water (insoluble fiber) and those that do (soluble fiber).  Insoluble fiber. This type of fiber promotes the movement of material through your digestive system and increases stool bulk, so it can be of benefit to those who struggle with constipation or irregular stools. Whole-wheat flour, wheat bran, nuts and many vegetables are good sources of insoluble fiber.  Soluble fiber. This type of fiber dissolves in water to form a gel-like material. It can help lower blood cholesterol and glucose levels. You can find generous quantities of soluble fiber in oats, peas, beans, apples, citrus fruits, carrots, and barley. The amount of each type of fiber varies in different plant foods. To receive the greatest health benefit, eat a wide variety of high-fiber foods. Benefits of a high-fiber diet A high-fiber diet has many benefits, which include:  Prevents constipation.  Lowers your risk of digestive conditions.  Lowers blood cholesterol levels.  Controls blood sugar levels.  Aids in weight loss.  Uncertain effect on colorectal cancer.. FIBER Classification of dietary fiber Type components examples physiological effects major food sources Insoluble 19 Noncarboydrate Lignin cereal bran under study all plants Carbohydrate Cellulose cereal products increases fecal bulk all plants Hemicelluloses brown rice decreases intestinal transit time wheat, rice, vegetables Soluble Carbohydrate Pectin, gums apple delaying gastric emptying citrus fruit Mucilage, some banana Slows glucose absorption oat products hemicelluloses carrot Can lower serum cholesterol eans barley oats kidney beans Increasing dietary fiber intake is not hard to do Try this Instead of this Dietary fiber bonus(g) Whole wheat bread, 1 slice white bread,1 slice 1.5 Brown rice, ½ cup white rice, ½ cup 0.5 Baked potato with skin, 1medium mashed potato, ½ cup 1.5 Unpeeled apple regular applesauce, ½ cup 1.5 Orange segments, 1 orange orange juice, 1 cup 1 Whole grain cereal, 1 cup sweetened cereal, 1 cup 2.5 Popcorn, 3 cups potato chips, 12 1 Bean dip, ¼ cup sour cream dip, ¼ cup 1.5 Kidney beans on salad, 2 tbsp coffee or tea 3 Fruit juice, 1 cup French fries, 12 1 20