1. Water

2. Importance  Water makes up 55-60% of the human body!  Losing 10% could cause death  Major function for life Digesting food Transporting nutrients Lubricant Regulate body temperature

3. Water Structure

4. Specific Heat  More energy to heat water than any other substance

5. Freezing Point  32°F/0°C  Lower temp decreases kinetic energy (motion)  Becomes less dense and floats  If something is added the freezing point changes

6. Melting Point  The temperature at which a solid changes to a liquid

7. Boiling Point  Pressure of steam=Pressure of atmosphere pushing down  212°F at sea level  Water will continue to get hotter as heat is continually applied  Food may cook faster

8. Atmospheric Pressure Steam Pressure =

9. Atmosphere Less Atmospheric pressure More atmospheric pressure = = Lower boiling point Higher boiling point At Sea Level = 212 F BELOW SEA LEVEL ABOVE SEA LEVEL

10. Water & Food  Ranges from 0-95%  Fruits and Veggies have the most  Grains and vegetable oils have the least

11. WATER CONTENT  FREE WATER  WATER THAT READILY SEPARATES FROM FOODS THAT ARE SLICED, DICED, OR DRIED BREAD CRISPING IN THE TOASTER  BOUND WATER  WATER THAT CANNOT BE SEPARATED IN FOOD Look at the next slide, would you think of drinking a tomato?

12. 2 15 3637 60 74 75 87 88 93

13. Functions in Food  Heat transfer  Universal solvent  Chemical reactions  Food preservation

14. Heat Transfer  Ensures heat is evenly distributed Ex: Baked Potato  Moist-Heat Cooking Boiling, simmering, steaming, stewing and braising

15. Universal Solvent  Biochemical reactions occurring in living things  Water forms solutions with minerals and water- soluble vitamins  Water dissolves caffeine and other flavor compounds

16. Definitions  Solvent – a substance, usually a liquid, in which another substance is dissolved  Solute – solid, liquid or gas compounds dissolved in another substance  Solution – A mixture of a solute dissolved in a solvent

17. Gas-in-water solutions  Carbonated beverages

18. Liquid in water solutions  Fruit juice concentrates  Vinegar & water (used to preserve pickled foods)

19. Solid-in-water solutions  Most common are sugar & salt  Cause water to freeze at lower temperature  Cause water to boil at higher temperature

20. Chemical Reactions  Makes nonessential amino acids  Helps enzymes function  Hydrolysis – water breaks down a chemical bond making a new substance Break down carbs, fats, & proteins for energy  Release of Carbon Dioxide

21. Food Preservation  Water is important for the life of microorganisms  Dehydrating food helps inhibit the growth of microorganisms

22. WATER TRIVIA  WATER IS IN EVERY BODY CELL  WATER DETERMINES THE SHAPE, SIZE, & FIRMNESS OF CELLS

23. REVIEW:  How does water’s function as a solvent play a role in human nutrition?  How does water help the body release excess heat?  Name 3 foods that are more than 50% water.