Задания

1. Ответьте на вопросы:

1. Why is water essential in our diet? 2. What are the functions of water in our body? 3. What are the daily requirements of water? 4. What are the sources of water in our body?

2. Укажите номера пропущенных слов.

Water is a major component of every body … , … and … . It plays an …role in almost every body function, including:

• Temperature …

• Transportation of … through the blood

• Acting as a necessary component of … reactions

• Aid in … of waste through urine and feces

• … of joints

• Acting as a major component of body fluids such as mucus and tears

• Giving the cells their shape and stability

_________________________________________________________________________

1.important, 2.tissue, 3.cell, 4.organ, 5.regulation, 6.shape and stability, 7.elimination, 8.chemical, 9.oxygen and nutrients, 10.lubrication, 11.mucus and tears.

WATER

1. Прочитайте текст и перечислите функции воды в организме человека.

2. Расскажите, почему нам необходимо знать о количестве воды в пищевых продуктах.

3. Выразите свою оценку значения воды для жизнедеятельности организма.

The water, chemical formula H₂O, is the major constituent of most foods. Although it brings any energy to food, its existence plays a very important role. It influences the structure, the appearance, taste of food and their susceptibility¹to degradation.

The water content of foods is very variable: 10 to 20% in cereals, 60 to 75% in meat and animal flesh, 80 to 90% in fruits and vegetables.

Water content of some foods
Food	Water content (%)
Beef	50 to 70
Chicken meat	74
Fish	65 to 81
Pears	80 to 85
Apples, peaches, oranges	85 to 90
Tomatoes, strawberries	90 to 95
Avocado, banana	74 to 80
Carrot, potato	80 to 90
Lettuce, lentils	90 to 95
Honey	20
Jam	28
Flour, rice	12
Milk powder	4

Knowing the water content of food products is often necessary for this:

Technological need: Knowledge of the water content of food is necessary for the efficient conduct of the operations of harvesting, drying, storage or processing. It is a key parameter for evaluating and controlling the risks of deterioration during storage of foodstuffs.

Regulatory need: If the regulations lay down the limits of water content of certain foods for reasons of hygiene or for guaranteeing the fairness of commercial transactions.

Need Contract: In case of commercial contracts require limited water content in food.

Need analysis: The results of analysis of food products are often expressed in relation to a fixed base (dry matter or water content standard).

Functional properties of water in food

Water has three main functions in food. These functions are:

Function solubilization (or dispersion): Water in foods is the solvent of the hydrophilic constituents.

Function structure: Water plays a key role in the pattern of food macromolecules, including proteins and carbohydrates. The water also determines the structure of certain constituents in the micelle. This applies, for example, casein in milk.

Mobilization function: water, compared to other fluids, is the mobility factor of the response in food products.

Expression of the amount of water in food

Water Content

The moisture content or humidity of a food is the amount of water lost by the substance when brought into balance with a true vapor pressure of zero (relative humidity of 0%). The amount of water lost is made up of water fixed by hydrogen bonds (water sorption, water held by capillary or osmotic, water solutions, water in occluse mesh and crystal water of crystallization); water chemically linked by covalent bonds is excluded.

The water content of a sample of food is expressed as% of water is reported to the mass of dry matter contained in the sample, ie the total mass of the moist of the sample.