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Water soluble vitamin's. Ascorbic acid (vit C)
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Water soluble vitamin's. Ascorbic acid (vit C)
It is colourless with tendency to become yellow in humid atmosphere, very soluble in water (30 gm in 100 ml), its thermostable in acid medium, very sensitive to oxygen.
Sources' in citrus, fruits, raw leafy vegetables, tomatoes, apple, peach and nuts.
Table 9. Vitamin С content of foods (mg in 100 g of products)
| wild roses | |
| strawberry | |
| cabbage | |
| apple | |
| potato | |
| carrot | |
| citrus | 40-60 |
| tomatoes |
Chemical characteristics:
• easily destroyed by heat (cooking)
• air causes loss of the value of vit. С
• it is not stored in the body so it must supplied daily.
Functions:
• for the production of the collagen of the fibrous tissue
• for metabolism of the amino acids
• it takes part in biological oxidation
• it takes part in the formation of hemoglobin
Daily requirements: children - up to 75 mg
Adults - up to 108 mg
Symptoms of hypovitamin
• weakness, loss of weight, Petechia
• swelling of gums, bleeding, gingivitis
• failure of fractures and flesh wounds to heal
• deficiency of vitamin С causes scurvy (arthritis, asiisamyelitis,
hemorrhage, weakness)
Vitamin toxicity (side effects)
• hypoglycemia
• oxalate stone formation in the urinary tract because of prolonged overdose
Exercise
Write your conclusion and recommendation about daily requirements of vitamin С for man, age of 30 years daily foods: apple - lOOg, rice - 200g, meat - 300g, tomatoes - lOOg, bread - 300 g, milk - 500 ml and vegetables - 200g
Fat - soluble vitamins
Vitamin A (Retmol) It is an alcohol and fat-soluble
External factors:
Low pH and light reduce its activity Vitamin A is stable if the
temperature is below 100°. Low temperature tends to preserve it. Prolonged heating in contact with air slowly destroys it.
Sources:
Animal fat, milk, liver, egg and fish
Vegetables ( b-carotene) in dark green vegetable as spinach and yellow vegetables as pumpkin, mango and carrot. In the body carotene is converted in to vitamin A. Six parts of carotene are equivalent to one part of vitamin A
p-carotene and other carotenoid pigments produce vitamin A.
b-carotene and other carotenoid pigments produce vitamin A during their absorption in the intestine
Table 10. Vitamin A content of foods (mg in lOOg of products)
| Carrot | |
| Tomatoes | 1, 2 |
| Milk | 0, 32 |
| Egg | 0, 6 |
Daily requirement
children - 1500 i u (about 400 microgram) adults - up to 8000 i u (750 microgram)
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Function of vitamin A:
• it is essential for night vision (formation of rhodopsm of the retina)
• Required for growth
• synthesis of glycoprotein
• anti infectious
• it is essential for epithelial cells
• anti xerophthalmic
Deficiency: leads to
• night blindness
• xerophthalmia (drying and thickening of the cornea
• hyperkeratosis of the skin
• delaying of growth
Hypervitaminos:
Acute toxicity: drowsiness, headache, imtability. Chtonictoxic - ity: alopecia, dry skin, eracked lips, headache, weakness.
Vitamin D
This thermostable fat soluble vitamin resistant to heat, oxygen, oxidizing agents and alkaline medium. Damage by light UV-rays and acids, occurs mainly in two forms:
• D 2 (Ergocalciferol) in yeast
• D 3 (Cholecalciferol)
Prepared in human skin by irradiation with UV rays medium waves from 7-dehydrocholestrol
Sources: butter, eggs, liver, milk. The best sources are fish liver
Oils.
Functions:
• prevent and to cure rickets (calcium metabolism)
• prevent osteomalacia (absorbtion of calcium and phosphorus inthe gut, directly concerned with calcification of bone)
Symptoms:
• rickets in children
• osteomalacia in adults
Daily dosage: Children - 400 iu, - Adults - 100 iu, Pregnant women -500 iu
Toxidty of vitamin D:
Hypervitammosis causes pathological changes in the dody (hypercalcemia)
• headache
• nausea
• diarrhea
• drowsiness
Exercise
Write your conclusion and recommendation about daily requirements of vitamin A for 15 years boy
Daily food: Milk - 100 ml, Egg - one, Bread - 300 g, Meat -| 200g, Carrot - 200g, Rice - 300g, Sugar - 50 g, Potatoes - 100 g
MILK AND DIARY PRODUCT
Milk is the most valuable food with high nutrition value. It is an ideal food for infant and children.
Cow milk contains (in 100 ml):
Energy - 67kcal Solids - 8, 1%
Fats - 3, 6% Calcium - 125mg
Lactose - 4, 9% Phosphors - lOOmg
Protiens - 3, 6% Acidity - 21°
Specific gravity - 1, 024-1, 034
For safty milk, coli- liter - 3ml, number of bacteria – 7500. The milk protiens contains Casein, Lactaalbumin and Lactoglobulin, milkfat is easily digestible, Carbohydrate is present in milk as lactose. Milk contains vitamins, but vitamin С is present only in very small quantities.
Milk born diseases
• tuberculosis
• brucellosis
• staphylococcal infection
• salmonellosis
• viral infection
• diphtheria
Milk treatment
Pasteurization: there are several methods a) Long term 30 min-
65°, b) Medial term 20 sec-75°, c) Instant term - 90°
Pasteurization causes minimum changes in the composition and nutritive value of milk and destroy all pathogens which may be present.
Sterilization: the milk must be heated under pressure and above 100° С which Destroys all bacteria.
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Diary products
Cheese – Protiens 12-16%, calcium - 8OOmg, phosphor - 400mg, fats - 25%
Sour cream - fats up to 36%
Curds (cottage cheese) - fats - 9-20% Protiens -12-16% Cal up to lOOmg
Kefir: is slightly alcoholic and acidic, prepared by the fermentation of milk with yeast's and Lactobacilli
Methods of falsification of milk:
1) To dilute with water
2) To use Starch after removal of fat from cream
3) To use alkaline
Tests for the purity of milk:
1) Specific gravity
2) Bacteriological tests
3) Phosphates test
Exercise
Write your conclusion about the sample of milk.
specific gravity - 1, 020
acidity - 24°
fats - 2, 8%
Protiens - 1, 5%
Colour - white yellowish
coli-titer - 3ml
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