- The human body contains about 65% water, with some tissues containing over 90% water. Plants and animals generally contain 60-90% water. - Different food products contain varying amounts of water, from around 3-4% in dry cookies to over 90% in foods like watermelon and milk. Meat contains around 50% water while vegetables can contain as much as 96% water. - Water plays an important role in many chemical reactions in foods and is essential for enzyme and bacterial activity. It has properties like crystallization and boiling points that impact food consistency, structure and other physical characteristics.

1. Water in various products.
Water plays an important role in the
human body and is involved in the
basic biochemical reactions, e.g.
breathing.

2. • The water content in most
plants and animals is about 60-
90%. The human body of an
adult contains about 65% of
water, but various tissues have
different water content. Teeth,
bones, hair contain the lowest
level of water whereas water
content in other tissues
exceeds 90%.

3. Water in food products :
• Bread: Bread contains approx. 30% of water,
dry cookies such as crackers 3-4%, and cakes
such as cheesecake and fruit pies - about 35%

4. • Dairy products: cheese - c. 38%, soft ripening
cheeses (eg. Camembert) - 58%, butter and
margarine- approx. 16%, milk - approx. 90%,
dairy cream- approx. 48-79%.

5. • Fish and seafood: fish- an average of approx.
75% of water, shellfish- about 85%, smoked
fish like mackerel- approx. 47%.

6. • Fruit: generally fruit contain approximately
75% of water, but fruits like watermelons,
melons contain up to 90% of water.

7. • Meat: Roast beef- approx. 50%, poultry - 65-
70%, sausages - 45-54%, salami-type
sausages contain less water as it level
reaches up to maximum of approx. 28%.

8. • Vegetables: they contain the most water
from all food products. Vegetables like carrot
or lettuce contain 89% of water, tomatoes-
93%, and cucumbers can consist of 96% of
water.

9. • The daily recommended intake of water
depends on the climate, place of residence,
physical activity and other factors. Please
note that some liquids such as coffee or
alcohol dehydrate, not without reason, so
coffee espresso given a small glass of water.

10. • Both raw materials and finished food products contain
large amounts of water. Because of the quantity and
properties which are different from the other
components water is an important factor influencing the
physical, chemical and biological changes of food, thus it
plays important role as far as food usability is concerned.
Such specific physical properties of water as a
crystallization in temperature of 0 ° C, boiling at 100 ° C
at atmospheric pressure, an increase of density with
simultaneous change of temperature between 0° C and
+4 ° C significant physical parameters values such as the
dielectric constant, surface tension, heat capacity, heat of
fusion and evaporation, dissolution capacity of many
substances and hydrating of natural polymers have a
decisive effect on the consistency, structure, rheological
properties, and many other physical characteristics and
physics-chemical of raw materials, semi-finished products
and finished food products.

11. • The water content determines the rate of progress of many
chemical reactions in foods, and for certain types of reaction, f. e.
hydrolysis water is absolutely essential. The activity of enzymes
and bacterial growth is impossible without water. The specific
properties of water are due to its molecular structure. The
molecular weight and the dipole nature of water is particularly
noteworthy. The molecular weight of the water is low; small size
of water molecules (high molar volume) compared with the size of
the molecules of other chemical compounds of other food
products cause easy ingress of water between the molecules of
other compounds.

12. Thank you for watching
our presentation!
Group 2