6.1 Factors that make food palatable
Palatability – reveres to food that is enjoyably eaten and pleasant tasting to the palate with a balanced flavor. For example making food to salt, sweet or bitter
Digestibility - the percentage of a foodstuff taken into the digestive tract that is absorbed into the body
Factors that affect palatability
1. Taste: food needs to consist of a balance of flavours that does not overpower but compliment the dish that is made.
2. Smell: plays an important role in the dish presentation. It is a way to make the guest imagine the flavours that is presented in the dish.
3. Appearance: “you eat with your eyes” the food presentation will activate your taste buds and make you want to eat the dish
4. Hygiene: if food is not prepared correctly and hygienically it will affect the overall end result. Lead to food poisoning and reduce the overall experience.
Fibre: A proper diet is conscious of calories, balanced nutrition, vitamins, avoidance of dangerous foods such as saturated fats, and attention to all sources of fiber.
A typical diet of meats, dairy products, breads made from enriched or refined flours, and other starches such as potatoes, pasta and rice are all very low in fiber.
Virtually all such meals contain a minimum of fiber, leading to a daily total of 5-8 grams.
Twenty Fiber Foods
This list can serve as a general guide. For more specific calorie and fiber content of particular foods, to estimate your daily and weekly quotas, refer to the alphabetical chart that follows: | |
1. | Dried beans, peas, and other legumes This includes baked beans, kidney beans, split peas, dried limas, garbanzos, pinto beans and black beans. |
2. | Bran cereals Topping this list are Bran Buds and All-Bran, but 100% Bran, Raisin Bran, Most and Cracklin' Bran are also excellent sources. |
3. | Fresh or frozen lima beans, both Fordhook and baby limas |
4. | Fresh or frozen green peas |
5. | Dried fruit, topped by figs, apricots and dates |
6. | Raspberries, blackberries and strawberries |
7. | Sweet corn, whether on the cob or cut off in kernels |
8. | Whole-wheat and other whole-grain cereal products. Rye, oats, buckwheat and stone-ground cornmeal are all high in fiber. Bread, pastas, pizzas, pancakes and muffins made with whole-grain flours. |
9. | Broccoli-very high in fiber! |
10. | Baked potato with the skin (The skin when crisp is the best part for fiber.) Mashed and boiled potatoes are good, too-but not french fries, which contain a high percentage of fat. |
11. | Green snap beans, pole beans, and broad beans (These are packaged frozen as Italian beans, in Europe they are known as haricot or french beans.) |
12. | Plums, pears, and apples The skin is edible, and are all high in pectin. |
13. | Raisins and prunes Not as high on the list as other dried fruits (see #5) but very valuable. |
14. | Greens Including spinach, beet greens, kale, collards, swiss chard and turnip greens. |
15. | Nuts Especially almonds, Brazil nuts, peanuts, and walnuts (Consume these sparingly, because of their high fat content.). |
16. | Cherries |
17. | Bananas |
18. | Carrots |
19. | Coconut (dried or fresh-but both are high in fat content). |
20. | Brussels sprouts |
Energy
Foods provide us with energy in the form of calories (Kcal).
Calories effectively act as the fuel that powers our bodies and enables us to function, in the same way that petrol fuels a car.
Some foods provide us with more energy than others, but by eating a wide variety of foods in the correct balance we can meet our requirements.
Foods that provide many nutrients relative to the amount of energy they contain are known as “nutrient rich” foods e.g. milk and dairy foods.
Energy requirements vary depending on age, sex, size, metabolic rate and activity level.
If we consume more energy/calories than we need, we deposit the excess energy in the form of fat or adipose tissue.
Conversely if we use more energy than we consume we use up fat to provide us with more energy.
Carbohydrate
Carbohydrates can be divided into two broad categories: available carbohydrate and unavailable carbohydrate.
Available carbohydrate
Sugars and starch are categorized as available carbohydrate.
Sugars are present naturally in fruit, vegetables and milk and are also added to many processed foods such as confectionery, cakes and biscuits.
Starch is found in foods such as bread, cereals and potatoes.
Both starch and sugars are digested in the body and converted to simple sugars (mainly glucose), which are then used by the body to provide energy.
Unavailable carbohydrate
Unavailable carbohydrate includes dietary fiber or NSP (non starch polysaccharide). The term “unavailable” is used because fiber can’t be digested and therefore doesn’t provide us with energy. However it is helpful in many other ways described below.
Dietary fiber can be divided into two categories: insoluble fiber and soluble fiber.
Insoluble fiber
Insoluble fiber (found in wholegrain cereals and grains, and some fruits and vegetables) adds bulk to the contents of the gut, speeding their transit and it is thought to help protect against constipation and other bowel disorders
Soluble fiber
Soluble fiber (found in pulses such as beans and lentils, fruit, vegetables and also oats, barley and rye) helps to reduce blood cholesterol levels and to regulate blood sugar levels.
At present the average intake of fiber in the UK is 14g/day in adults. Experts recommend that fiber intakes should be as high as 18g/day.
Consumption of brown, wholegrain, wholemeal and high fiber varieties of carbohydrate will help to increase fiber intake.
Protein
Proteins are essential for growth and maintenance of body tissues and for the production of substances such as hormones and enzymes which help to control many functions within the body. If insufficient carbohydrate and fat are available in the diet, then protein may also be used to provide the body with energy.
Proteins are made from building blocks known as amino acids.
There are 20 different amino acids.
Some amino acids can be made in the body and others can only be supplied by the diet -these are known as the essential amino acids.
Some foods are better providers of these amino acids than others. Those which contain all the essential amino acids are known as “high biological value” foods e.g. milk and dairy foods, meat, eggs etc.
Those which contain fewer of the essential amino acids are known as “low biological value” foods e.g. cereals, beans, lentils and nuts.
However if a wide variety of foods are consumed in the correct proportions the different protein sources can work together to provide the ideal levels of the different amino acids.
Fat
Fats are essential for many reasons:
- They are a provider of energy
- They are involved in forming cell membranes
- They are a vehicle for the provision of fat soluble vitamins such as Vitamins A, E, D and K
- They are involved in making hormones
- They provide insulation; keeping us warm.
- They provide us with a shock absorbing, protective layer
Fats are made from building blocks called fatty acids.
There are three types of fatty acids - saturated, monounsaturated and polyunsaturated fatty acids.
The fat in food contains a mixture of all three fatty acids, in different proportions in different foods.
Saturated fats
Foods that contain the higher proportion of saturated fatty acids include fats and oils (e.g. butter, hard margarine, some blended cooking oils), meat and its products (e.g. pies, lard, suet), whole milk and its products, coconut and palm oil.
Monounsaturated fats
Olives, olive oil and rapeseed oil are the best providers of monounsaturated fatty acids.
Polyunsaturated fats
Fats and oils containing large amounts of polyunsaturated fatty acids are derived mainly from seeds and nuts and include pure sunflower, safflower, sesame, soya, corn oils, and sunflower and soya margarine.
Two polyunsaturated fatty acids, linoleic and alpha-linolenic acids cannot be made in the body and must be provided in the diet. These are called essential fatty acids.
These essential fatty acids are known as the "parent" fatty acids of 2 families of unsaturated fatty acids. The parent fatty acids undergo various different chemical reactions to produce the different fatty acids within each family, which have numerous different and important functions within the body.
Linoleic acid is the parent fatty acid of the n-6 family of fatty acids and alpha-linolenic acid is the parent fatty acid of the n-3 family of fatty acids.
Vegetable oils, eggs and poultry are good providers of n-6 fatty acids which are important for the formation of membranes in the body.
Unrefined fish oils and oily fish such as salmon, mackerel and sardines are good providers of n-3 or Omega 3 fatty acids which are important for the correct formation of nerves and have been linked to numerous health benefits such as reduced risk of cardiovascular disease and improved brain function.
Experts advise that too much fat, in particular saturated fatty acids, may lead to raised levels of blood cholesterol in some people which, in turn, is a risk factor for coronary heart disease.
As a result, government guidelines recommend that fat should provide no more than 35% of daily food energy, with saturates providing no more than 11%, polyunsaturates contributing no more than 6.5% and trans fatty acids no more than 2% of the daily food energy intake.
NB: These recommendations for fat intake do not apply to children under five years of age.
Trans fats
Trans fats are formed when the structure of monounsaturated and polyunsaturated fats are altered during a process called hydrogenation. They are often found in processed foods such as biscuits, cakes and margarine's.
Trans fatty acids found in industrially produced products have been shown to have a negative effect on risk factors for CVD. In the UK efforts have been made to reduce or remove trans fatty acids from margarine's and spreads through the use of new techniques and many now have minimal amounts of trans fatty acids.
Trans fatty acids also occur naturally in small amounts in milk and milk products and have been created in the stomach of ruminant animals (such as cows and sheep).
Vitamins, minerals and trace elements
Vitamins, minerals and trace elements are required for numerous functions within the body and deficiencies can lead to serious health problems.
They are required in much smaller amounts than fats, carbohydrates and proteins and are therefore known as micro nutrients.
The department of health recommends specific amounts of each micro nutrient for certain sub groups of the population known as dietary reference values (DRVs).
The department of health recommends specific amounts of each micro nutrient for certain sub groups of the population known as dietary reference values (DRVs).
These recommendations only apply to healthy people and should only be used as a general guideline as individual requirements are likely to vary.
There are two types of vitamins, water-soluble and fat soluble.
Water-soluble vitamins
Water soluble vitamins travel around the body in the bloodstream and are picked up by cells when they are needed. Water-soluble vitamins that are not required by the body are excreted in the urine.
Fat soluble vitamins
Fat soluble vitamins are stored in body fat (for a few days or as long as 6 months) until the body needs them.
- Water soluble vitamins:
- Vitamin B1 (thiamin)
- Vitamin B2 (riboflavin)
- Vitamin B6
- Vitamin B12
- Folate
- Niacin
- Biotin
- Pantothenic acid
- Vitamin C
- Fat soluble vitamins:
- Vitamin A
- Vitamin D
- Vitamin E
- Vitamin K
Minerals and trace elements
Minerals and trace elements are similar to vitamins and are required in very small or trace amounts to maintain good health.
Minerals tend to be required in milligram (mg) quantities and trace elements tend to be required in much smaller amounts - microgram (μg) quantities.
Some are found only in a few foods, so it is important that these foods are included in the diet on a regular basis e.g. the main providers of calcium in the diet are milk, cheese and yogurt . Some foods are also fortified with minerals, for example, iron is added to some breakfast cereals.
- Minerals:
- Calcium
- Chloride
- Fluoride
- Iron
- Magnesium
- Phosphorus
- Potassium
- Sodium
- Zinc
- Trace elements:
- Copper
- Chromium
- Iodine
- Manganese
- Molybdenum
- Selenium
Consumption of a balanced and varied diet should ensure adequate levels of all vitamins, minerals and trace elements are received.
It is always better to receive the recommended levels of vitamins, minerals and trace elements through consumption of food sources rather than artificial supplements. However supplements are sometimes useful, particularly if you have an increased requirement for one or several nutrients e.g. pregnant women, infants, older people who don't go out of doors or ethnic groups who wear coverall clothing etc.
6.3 NUTRIENTS FOUND IN FOOD
Nutrient | Best sources | Best sources | Deficiency Symptoms |
Carbohydrates | Starches / sugars | Furnish body heat and energy | Lack of energy Loss of weight |
Fats | butter | Furnish body heat and energy. Transport vitamins A, D, E and K. Supply essential fatty acids. | Loss of weight. Retarded growth. Poor condition of skin and hair. |
Protien | meat | Build, repair and maintain body tissue. Furnish body heat and energy. | Retarded growth. Premature old age. Poor muscle tone. Slow mental reactions. Lowered resistance to disease. |
Calcuim | milk cheese green vegetables | Essential for bones | Tooth decay Rickets Retarded growth Slow clotting time of blood |
Phosphorous | Internal organs | Essential for teeth | Tooth decay Rickets Retarded growth |
Iron | Internal organs (especially liver) | Needed for formation of red blood cells | Anemia |
Vitamin B | Whole grain cereals | growth | Retarded growth Loss of appetite and weight Lack of energy Nervousness |
Vitamin B2 or G (riboflavin) | milk | growth | Retarded growth Inflammation of skin and tongue Impaired vision |
Niacin | Internal organs | growth | retarded growth skin disorders digestive disturbances mental disorders |
Pantothenic Acid | liver | Essential for: growth healthy skin and hair | ???? |
Vitamin C | Citrus fruits | growth | retarded growth tender or bleeding gums Bruise easy |
Iodine | iodized salt salt water sea food | normal function of thyroid gland | Simple goiter |
Vitamin A | Fish liver oils | growth normal function of eyes Health of skin and mucous membranes | retarded growth night blindness lowered resistance to disease poor condition of skin and mucous membranes |
Vitamin D | Summer sunshine | growth | retared growth tooth decay rickets |
Vitamin E | seed germ oils green vegetables | growth | ????? |
Vitamin K | green vegetables cabbage cauliflower tomatoes | clotting of the blood | Hemorrhages |
6.4 essential dietary requirements
Minerals
There are about 18 principle minerals but only very small amounts are needed of most of them. The major nutritional minerals are:
Calcium is a major constituent of bones (30%), but calcium is also found in cells (particularly muscle cells) and in the blood. Calcium is essential to muscle contraction and to the normal functioning of many enzymes. It is necessary for the formation of bone and teeth, for blood clotting, and for normal heart rhythm.
Iron is an important component of haemoglobin (carries oxygen in red blood cells) and muscle cells. Iron is also necessary for the formation of many enzymes in the body.
Zinc is a component of more than a hundred enzymes, including those involved in the formation of DNA. It is also essential for healthy skin, healing of wounds, and growth. Much of the zinc consumed in the diet is not absorbed.
Magnesium is necessary for the formation of bone and teeth and for normal nerve and muscle function. Many enzymes in the body depend on magnesium to function normally.
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