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Role fats in nutrition. Classification of the fat acids. Value phosphatides. Value of carbohydrates in nutrition. Classification carbohydrates.
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ROLE FATS IN NUTRITION
Structure of food fats: neutral fats (the ethers of glycerin and fat acids), fat-like substances - phosphatides, mineral substances, fat-soluble vitamins (in some fats).
Functions of fats in nutrition: power (30-32 % daily calory, 1g fat makes 9 Kcal), regulatory, plastic, protective (from mechanical and temperature influences), flavouring.
Classification of the fat acids.
Fat acids share under the contents of free (double) connections in formula on saturated, nonsaturated and polynonsaturated.
1) Saturated fat acids (SFA) - stearin, palmytin acids in animal fats, oil and kapron - in vegetative. Nonreactive, are acquired worse others, carry out basically power function. Contain in the beef, mutton fat. At the superfluous use promote development atherosclerosis due to a plenty cholesterol.
2) Monononsaturated fat acids (MNFA) – olein acid - contain 1 free connection in formula, are better soaked up, basically - power function. It is in vegetative fats.
3) Polynonsaturated (PNSA) - linolev, arachidon acids (family omega-6), linolenov acid etc. (omega-3). Have some free connections in formula. Most biologically active and valuable among fat acids:
- regulative function - adjust exchange of cholesterol (the antisclerotic factor), reduce coagulability of blood and permeability of vessels.
- Protective function - raise resistancy organism to infections, тoxicants, to surplus ultra-violet rays (antioxidizers).
- Plastic - are part of walls of vessels and мielyn environments of nerves.
Suppliers of PNSA: PNSA family omega-6 contain in not refined vegetable oils, PNSA omega - 3 - contain in fat of sea fishes (are most biologically active).
Value phosphatides.
It is fat-like substances - 1 fatty acid is replaced with a phosphoric acid and the nitrogenous basis.
Representatives: lecithin, kefalin. Participate in synthesis nuclein acids, in exchange cholesterol (antisclerous factor). A plastic role - enter into protoplasm of cells, especially nervous system and a liver.
Suppliers: liver, brain, egg yolk, butter, lard, not refined vegetable oils.
Sterines. Share on phytosterines and zoosterines.
Cholesterol.
Despite of ordinary opinion on its harm, cholesterol is very important for an organism. It has plastic function - contains in protoplasm of cells, creates elasticity of fabrics as hydrophyl colloid due to keeping water. Regulative function - synthesis vitamin D, bilious acids, sexual and steroid hormones. Protective function – inactives haemolytic poisons.
On modern representations, development atherosclerosis has multifactorial aethiology, in a basis - infringements of a fatty exchange and increased endogenic synthesis cholesterol, surplus alimentary cholesterol plays rather small value - an alimentary risk factor of atherosclerosis.
VALUE OF CARBOHYDRATES IN NUTRITION
Functions of carbohydrates:
1) Power function (56 % caloric content of a diet per day), 1 g = 4 Kcal.,
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2) regulatory (cellular tissue stimulates a motility and secretion of intestines),
3) Plastic (enter in structure of protoplasm and cellular membranes),
4) Protective (connect with heavy metals, cholesterol, glucose inactived cianid poisons),
5) Flavouring - sweet taste.
Classification carbohydrates.
| CHEMICAL | HYGIENIC |
| 1. Monosaccharides ( Glucose, fructose) | 1. Unprotected (refined) |
| 2. Disaccharides ( Saccharose, lactose) | 2. Protected (starch) |
| 3. Polysaccharides ( starch, pectins) | 1. Superprotected 1)Cellulose 2) Pectic substances |
In hygiene carbohydrates share on a degree of mastering:
1) Unprotected (refined) carbohydrates (mono- and disacharides – glukose, laktose, etc. ). Quickly are absorbed in organism and give energy. At the use plenty of such carbohydrates may be alimentary odiposity, dibetes and caries.
2) Protected carbohydrates (starch). It has slow absorb in organism and give most of all energy.
3) Superprotected: а) Cellular tissue, b) Pectin substances.
VALUE VITAMINS IN NUTRITION
Vitamins – it is low-molecular organic substances, biologically active in very small amounts. Functions of vitamins:
а) regulatory - form enzymes and adjust in metabolism,
b) protective - raise resistancy an organism to the adverse climatic factors, harmful physical and chemical influences, infections etc. (vitamin C - antioxidizer).
CLASSIFICATION VITAMINS:
WATER-SOLUBLE VITAMINS
Vitamin C - Acidum ascorbinicum
Vitamin В1 - Thiaminum
Hepatoflavin - Riboflavinum
Vitamin В3 or В5 - panthotenon acid
Vitamin B 6 - pyridoxine, pyridoxal, pyridoxamine
Vitamin В12 - cyancobolamyn
Vitamin Н - biotin
Vitamin РР - Niacinum, niacin, Nicotinamidum
Acidum folicum
LIPOSOLUBLE VITAMINS
Vitamin A - Retinolum, retinolacetat, retynal
Vitamin D - ergocalciferol (D2), cholecalciferol (D3)
Vitamin E - admixture of tocopherols
Vitamin K - admixture of naphthoquinones
VITAMIN-LIKE SUBSTANCES:
Choline Biologically fissile materials:
Inosite (B 8) Bioflavonoids
Acidum lipoicum - Vitamin U
Orotovic acid (B 15)
Vitamin В15 - pangamic acid
Carnitine
Paraaminobenzolic acid
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