| Why do we cook? To render appertising and aid digestion to provide the body with nutrience essential for growth and repair.Food is required by the body –
(a) to build it up and keep it in repair
(b) to supply heat and energy
(c) to protect it from disease
Each of these functions is equally important : each must be considered as bearing a close relationship with the others.
The chief constituents of food are : proteins, carbohydrates, fats, mineral salts, water, roughage and vitamins.
The body builders are : protein, mineral salts and water.
The fuel and energy foods are : carbohydrates (starch and sugar), fats and proteins.
The protective foods are : 8-10 essential vitamins, mineral salts and roughage.
Protein
builds up the body and keeps it in repair. No other food can do this, so protein is essential in the diet. Children and adolescents requireit for growth as well as for the repair of tissue that is constantly being used up. It is broken down into Amino Acids – the body can’t store amino acids.
All movement entails wear and tear, and if this is not made up by suitable food, the health will be seriously affected.
There are two sources of protein-animal and vegetable foods.
Blood protein - hormones, genes (haemoglobin) muscle movement, structural bones, nails, skin.
Haemoglobin – carbon, hydrogen, oxygen, sulphur, carries oxygen in the blood.
Animal or first class protein is obtained from : meat, poultry, game, fish, cheese, eggs and milk, and is of better quality than Vegetable or second class protein, which is obtained from pulse foods (peas, beans and lentils), nuts, unpolished cereals, brown flour, potatoes.
Carbohydrates
to supply peoples main source of energy, are made up of starches and sugars. Starch is found in cereals, grain, and some root vegetables-especially potatoes. Sugar is found is sugar treacle, syrup, honey, beetroot, fruit, milk.
Fat
is an energy and heat giver. It produces about twice as much energy as carbohydrates and is invaluable in producing heat in winter. Fats are of animal or vegetable origin.
Animal fats
are: butter, cream, cheese, lard, dripping, the fat of meat, the fat of oily fish, egg yolk.
Vegetable fats
are: nut oils, vegetable oils, olive oil.
Supply of essential fatty acids, aids absorbtion of fat-soluble vitamins (A, D, E, K).
Mineral salts
are so important in the building of the body that, in this sense, it may be regarded as a food. The chief mineral substances are : sodium, potassium, calcium, phosphorus, iron and iodine.
Sodium
(found in common salt) is required by the fluid in the body. Vegetarians usually require more salt that animal food eaters, because of the large amount of potassium in vegetable products, which has to be counterbalanced by sodium.
Potassium
(found in vegetables and fruits) is required for the cells of the body.
Calcium
( found in milk, cheese, eggs, green vegetables and nuts) is needed by almost every tissue of the body, especially bones. If calcium is cut out of the diet, the muscles will eventually lose their power. Calcium is necessary too, to enable blood to clot. A growing child requires about twice as much as an adult.
Phosphorus
(found in milk, cheese, eggs, fish, liver, sweetbreads and wholemeal flour) is required especially by nerves and bones : hence nerve tonics of phosphorus. To obtain it from food in a natural way is much the best plan.
(Vitamin D aids the use of calcium and phosphorus.)
Iron
(found in liver, meat, pulse vegetables, green vegetables, raisins, oatmeal, wholemeal flour, parsley) is necessary for the red colouring matter in the blood. Bloodlessness and, later, anaemia are due to lack of iron.
Iodine
(found in fish, watercress and in “iodised” salt) is necessary to the thyroid gland in the neck which controls, in some measure, development of the body. If there is insufficient iodine in the diet, goitre results. At or near the sea there is always an abundance, and it is carried by the wind and spray inland, where it is found in water, in soil and consequently in food. The very sheltered areas are lacking in iodine.
Water
( found in almost every food) is an absolute necessity in the diet. It is contained in every tissue, and nearly three-quarters of the body’s weight is due to it. It is the purifying agent in the body, for it carries the waste and injurious matter to the excretory organs. The body requires about 2.5L a day to make up for the loss by skin, kidneys and lungs. About one third of this is obtained from solid food and the remainder from beverages and water.
Roughage
(founding vegetables, fruit, oatmeal, wholemeal and brown flour) is indigestible matter which has no actual nutritive value but which is essential to health. It helps to stimulate the movements of the large intestine and, by preventing constipation, protects body from ill health.
Vitamins
– Catalysts for the body, as their name implies, are substances vital to life – essential to the growth of children. Their absence from the diet causes deficiency diseases, i.e. diseases due to some deficiency in the diet. At first there is just general ill health, but more dangerous symptoms appear if the lack of vitamins persists. To those who say our great grandparents knew
nothing of vitamins and that they did not suffer from a lack of then one answer is they ate foods which had not been submitted to refining processes in manufacture, e.g. home milled flour verses white flour.
Vitamins for regulation of body processes
- Fat soluble – A, D, E, K.
- Water soluble – C, B.
The most well known vitamins to date are:
Vitamin A
, found in dairy products, animal fats, green vegetables, carrots, tomatoes, and particularly halibut and cod liver oil. This vitamin is destroyed by drying and heating if air is present and also, though more slowly, by becoming stale. Vitamin A prevents eye disease, promotes growth and helps in resistance to disease and infection. Vitamin A is resistant to heat.
Vitamin B1
( known as F in America) is found in yeast, and yeast extracts, e.g. marmite, grain of wheat (e.g. Nemax, wholemeal flour), liver. This vitamin is destroyed by sterilisation and the action of alkali – and slowly, by staleness. It strengthens the nervous system and protects from neuritis, prevents constipation and beri-beri (a disease in countries such as Japan and India).
Vitamin B2
(or G in America) is found in lean meat, fish, egg yolk, milk, tomatoes, liver, Marmite and Bemax. This vitamin is not affected by heat or
sterilisation. It promotes growth in the young and plays a part in the health of the skin. It prevents pellagras-very rare in this country
but prevalent among peasants in S. Europe.
Vitamin C
is found in fruit and vegetables-especially raw vegetables, tomatoes, oranges, lemons, grapefruit and germinated pulses. This vitamin is
destroyed by drying in the presence of air, by heat, by the action of an alkali, e.g. soda, by staleness and frequently by sterilisation.
Shortage of this vitamin causes tiredness, lowered resistance to infection and in extreme cases, scurvy.
Vitamin D
(usually associated with vitamin A) is found in dairy products, animal fats (except lard), halibut and cod liver oils. This vitamin is
destroyed by overlong exposure to light. It prevents rickets and the decay of teeth. Vitamin D is resistant to heat.
Vitamin E
is found in meat, eggs, green vegetables and wheat grain. It has value in the process of reproduction and lactation. It is not affected by
exposure to air.
A balanced diet
In planning meals it is important to see that body builders, fuel foods and protective foods are all included daily. The foods most likely to be neglected are the protective foods. If care is taken to include these they, plus a varied mixed diet, will ensure good health.
Speaking generally, the chief food groups should be in the proportion of 1/6 protein, 1/6 fat to 2/3 carbohydrates. To obtain adequate amounts of protective material the diet should contain milk cheese butter or vitaminised margarine, egg, herring, citrus fruits, raw salads, tomatoes, wholemeal bread.
There are several methods of achieving the balanced meal, e.g. by measuring the heat producing or calorific value of foods; but the standard diet given will meet essential requirements in any system of measurement.
Foods required by the body
| Name of food |
Food in which found |
Function of the food |
Protein
is not stored, it’s continually being lost: |
|
|
| a) Animal protein |
Meat, poultry, game, fish, cheese eggs and milk |
To build the bodyTo repair tissueTo give heat and energy
(A reserve only.) |
| b) Vegetable protein |
Pulse foods, nuts, unpolished cereals, brown flour, potatoes |
Carbohydrates
compounds of Carbon, Hydrogen & Oxygen |
|
|
| a) starch |
Cereals, grain, some root vegetables especially potatoes. |
To give heat and energyTo help utilise the fat. |
| b) Sugar |
Sugar, treacle, syrup, honey, beetroot, fruit, milk |
| Fats |
|
|
| a) Animal fatUnsaturated |
Butter, cream, cheese, lard, dripping, fat of meat, fat of oily fish |
To give heat and energyTo provide for future use by storing it. |
| b)Vegetable fat |
Nuts, oils, vegetable oils, olive oil. |
| Polyunsaturated |
Florene, water, toothpaste, bony fish |
To strengthen enamel on teeth. |
| Mineral Matter |
|
|
| a) Sodium |
Common salt |
To assist the fluid of the body in its work |
| b) potassium |
Vegetables and fruit |
To assist the cells of the body in their work |
| c) Calcium |
Milk, cheese, eggs, greens, nuts |
To strengthen tissues and bones |
| d) Phosphorus |
Milk, cheese, eggs, fish, liver, sweetbread, and wholemeal flour. |
To strengthen nerves and bones |
| e) Iron |
Liver, meat, pulse food, greens, raisins, prunes, oatmeal, wholemeal flour, parsley. |
To assist the red colouring in the blood. Haemoglobin, in red bloods cells carry oxygen in the blood. |
| f) Iodine |
Fish, watercress, iodised salt |
To help in the work of the thyroid gland. |
| Water |
All foods |
To purify the bloodTo carry away waste matterTo form tissue |
| Roughage |
Vegetables, fruit, oatmeal, wholemeal flour |
To prevent constipationTo protect the body from ill health |
| Vitamins |
|
|
| Vitamin A |
Dairy produce, animals fats, green vegetables, carrots, tomatoes, halibut and cod liver oils |
To prevent eye diseaseTo promote growthTo help in resisting disease |
| Vitamin B1 (or F) |
Yeast, marmite, germ of wheat, Bemax, egg, pulse foods, wholemeal flour, liver. |
To strengthen the nervous systemTo protect from neuritisTo prevent constipation
To prevent beri-beri |
| Vitamin b2 (or g) |
Lean meat, fish, egg yolk, milk, tomatoes, liver, marmite, bemax |
To promote growth in the youngTo aid the health of skinTo prevent pellagra |
| Vitamin C |
Fruit, vegetables (especially raw), tomato, oranges, lemons, grapefruit and germinated pulses. |
To prevent lowered resistance to infectionTo prevent scurvy |
| Vitamin D |
Animal fat, halibut and cod liver oils |
To prevent ricketsTo prevent decay of teeth |
| Vitamin E |
Meat, eggs, green vegetables, wheat germs. |
|
Calcium, phosphorus, Vitamin B – formation in skin through sulphur – ultraviolet light – deficiency
rickets. |
|
Enzymes
Definition: A Catalyst – enables chemical change – remains unchanged.
Enzymes are in all living cells. Enzymes are protein. Needs water.
Examples: Meat tenderising Thickens coagulate
Yoghurt Breaks down tissue
Digestion
Death: causes enzymes to self-destruct.
Methods of preservation
- Heat – canning
- Low temp - freezing
- Chemicals – osmosis alcohol
- Dehydration – (AFD) Artificial Freeze Drying
- Irradiation – ionising radiation
Canning temp – above 100oC for 8-10 mins.
Freezing - plate - blast
- immersed - bed freezing
Chemical - vinegar, sugar - Sodium chloride - alcohol - Sodium & potassium nitrate |
