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Water (and calories). (Note change of topic order). DVD on Calories. Experiential Exposition of Calorie. Energy and Engineering Properties. calorie = amt of Energy required to raise 1 gram H 2 0 1 °C C alorie (kcal) = amt of Energy required to raise 1 liter H 2 0 1 C °
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Water (and calories) Dr. Thomas J. Montville
(Note change of topic order) DVD on Calories Dr. Thomas J. Montville
Experiential Exposition of Calorie Dr. Thomas J. Montville
Energy and Engineering Properties • calorie = amt of Energy required to raise 1 gram H20 1°C • Calorie (kcal) = amt of Energy required to raise 1 liter H20 1C ° ~ 1 quart of water by 0.5 ° F (1 C° = 5/9 F°) Dr. Thomas J. Montville
More on Calories How many Calories does an ounce of water have? Dr. Thomas J. Montville
More on Calories How many Calories does an ounce of water have? None Dr. Thomas J. Montville
More on Calories What about steam? It has energy? Steam stores or transfers energy. Dr. Thomas J. Montville
Consider the ice water diet • How much ice water would you have to drink to lose 1 pound? • How many Calories would it take to raise 1 liter of water from 0 to 37 C? • 37 Calories to raise 1 liter (~quart), 3500 C/pound 37 C per qt. = 94 quarts or ~ 24 gal Dr. Thomas J. Montville
Consider sweat Energy of vaporization = 540 Calories to evaporate a liter of sweat Dr. Thomas J. Montville
“Hydrate, Urinate, Celebrate” If a cyclist expends 540 calories/hour riding a bike, how much fluid should he be drinking? If his urine is dark and only 100 ml/hr, what does that mean? Why is sweat good? Danger of Hyponatremia Dr. Thomas J. Montville
“Energy” Drinks Dr. Thomas J. Montville
Questions? Comments? Dr. Thomas J. Montville
Water Friend or Foe? Water, Friend or Foe? Dr. Thomas J. Montville
Water,an amazing molecule and our first chemical (ingredient) Uses in food Chemistry Physical properties Water in foods Water in nutrition http://www.estrellamountain.edu/faculty/farabee/biobk/biobooktoc.html Dr. Thomas J. Montville
Uses of water in food • Solvent • Carrier – (Lakes, emulsion) • Force – (Cleaning) • Product • Adulterant • Preserve Freshness • Texture - (Juiciness) Dr. Thomas J. Montville
“Water added” Dr. Thomas J. Montville
More uses of water in food • Appearance • Heat sink – see next • Chemical reactant and product • Emulsion • Structure • Energy (microwave heating) • http://www.koreus.com/video/telephone-portable-mais-popcorn.html 14. Agriculture Dr. Thomas J. Montville
Heat Sink due to Specific Heat • Specific Heat = amount of energy required to raise 1 gram of water 1°C. • The specific heat of water = 1 • Specific heat of air = 0.25 Dr. Thomas J. Montville
Water Chemistry “Hydrogen bonding” is nothing more than the attraction of positive and negative. Dr. Thomas J. Montville
Hydrogen bonding Physical Properties Energy Hydrogen bonds are relatively weak. Dr. Thomas J. Montville
Boling Point vs. Altitude (Vacuum) Freeze Drier Low altitude Low melting point Low boiling point High altitude High boiling point Dr. Thomas J. Montville
Boling point vs. Altitude Dr. Thomas J. Montville
Three phases of water Venus GAS Look at different planets. Where’s earth? Temperature Liquid Mars Solid Earth Pressure Dr. Thomas J. Montville
Three phases of water Venus GAS Where’s Uranus? Temperature Liquid Mars Solid Pressure Dr. Thomas J. Montville
Three phases of water Venus GAS Where’s Uranus? Temperature Due to high atmospheric pressure and large gravitational force, water exists only as solid. Liquid Mars Solid Pressure Dr. Thomas J. Montville
Vapor Dr. Thomas J. Montville
Vapor Energy of fusion = 80 Calories/liter ? to 32 F 32 F 32-212 212 - ? Energy of vaporization = 540 Calories/liter Dr. Thomas J. Montville
Three phases Low freezing point High boiling point High heat capacity Polarity Low density Expands when frozen Ability to conduct heat” ice 4x faster than water, 4x faster than air. (Ice melts faster than water freezes.) Physical Properties of Water Dr. Thomas J. Montville
Water in Food, Three types • Constitutive water • < 0.3% in high water food • Immobile, unfreezable • Multilayer water • 0.5 – 3% • Some solvent capacity • Bulk water • 96%, free & entrapped, reactive, freezeable, Dr. Thomas J. Montville
Water activity concept Salad dressing and honey are both ~ 50% water, but the availability of the water is different. Dr. Thomas J. Montville
Essential to life Chemical Carrier of water soluble vitamins Incompressible Amniotic fluid Temperature regulation Need 1 g / cal expended Substance % H20 You 65 Beef & pork 60 Chicken 75 “hard” fruit 80-90 “soft” fruit 90-95 Water and Nutrition Dr. Thomas J. Montville