Transcript FATS AND OILS

Food Chemistry
Chapter 17 in Green / Damjii
F.1: Food Groups
Homework
• Read F1 – Food Groups - pp. 475-476
• Do Qs 1-6 (on p 490)
and/or take notes on the sections
• Participate in interactive lecture in class and
take study notes
F.1: Food Groups
• F.1.1: Distinguish between a food and a
nutrient
Food
• Any substance we deliberately take into our
mouths and swallow.
• Any natural or artificial material intended for
human consumption
• Contains one or more nutrients
Nutrient
Component of food that is used by the body to
• provide energy
• Aide in growth and/or repair of tissue
A lack of these nutrients may cause
• malnutrition
Major Nutrients
• Lipids
• Carbohydrates
• Proteins
Other Nutrients
• Vitamins
• Minerals
• Water
F.1: Food Groups
• F.1.2: Describe the chemical composition of
lipids (fats and oils), carbohydrates, and
proteins.
Major Nutrient - Lipids
Fats and Oils are…
• Source of Energy
• Vital in constructing cell membranes
Major Nutrient - Lipids
• Contain C, H, O
• Esters of glycerol and 3 fatty acids
– Aka triglycerides
http://www.ilri.org/infoserv/webpub/fulldocs/ilca_manual4/images/fig_pg9.g
if
Triglycerides
“R” group can be…
• SATURATED (no double or triple bonds)
– Tend to be SOLIDS at room temperature
– Tend to come from animal products
– “Fat”
• Unsaturated (has one double or triple bond)
– Tend to be LIQUIDS at room temperature
– Tend to come from plant material
– “Oil”
• Polyunsaturated (has multiple double or triple bonds)
Nature of “R” group determines physical and chemical
properties.
Which of these lipids is saturated?
Unsaturated? Polyunsaturated?
B 
A
C 
Which of these lipids is saturated?
Unsaturated? Polyunsaturated?
Citations for images on previous slide
http://wpcontent.answers.com/wikipedia/commons/thumb/b/be/Fat_triglyceride_s
horthand_formula.PNG/220px-Fat_triglyceride_shorthand_formula.PNG
http://www.biology.lsu.edu/introbio/Link2/triglyceride.gif
http://www.chm.bris.ac.uk/motm/ethylacetate/triglyceride.gif
What about this one?
http://www.bio.miami.edu/~cmallery/150/che
mistry/c4x5fatmolecule.jpg
Which of these lipids is saturated? Unsaturated?
Polyunsaturated?
Major Nutrient - Carbohydrates
Carbohydrates are…
• Source of Energy
• Vital in cell construction
Major Nutrient - Carbohydrates
• Empirical Formula = CH2O
Major Nutrient - Carbohydrates
• Simple Carbohydrates
• Monosaccharides = (CH2O) n>2 = simplest
carbohydrates
Ex: Glucose
fructose
Major Nutrient - Carbohydrates
• Disaccharide – formed from condensation of 2
monosaccharides.
Major Nutrient - Carbohydrates
• Polysaccharides – formed from condensation
of many monosaccharides.
Starch
Major Nutrient - Proteins
Proteins …
• build up, maintain, and replace tissues
(muscles, organs, imunne system) in your
body
• Primary component in hair and nails
• make enzymes, hormones, and other body
chemicals
• building block of bones, muscles, cartilage,
skin, and blood.
Major Nutrient - Proteins
• Contain C, H, O, and N…
– And some contain P and S
• Are polymers of amino acids
• 22 important amino acids
– 13 body makes, 9 are “essential”
Major Nutrient - Proteins
Major Nutrient - Proteins
The R groups represent side chains of the amino
acids involved and can be the same or different.
Food Chemistry
Chapter 17 in Green / Damjii
F.2: FATS AND OILS
Homework (Done in advance!)
• Read F2 – Fats and Oils - pp. 476-477
• Do Q 7-11
• on p 491
F.2:
Fats and Oils
• F.2.1: Describe the difference in structure
between saturated and unsaturated (monoand poly-unsaturated) fatty acids
Remember… 3 molecules of
fatty acids react with 1 molecules
of glycerol to form a lipid
F.2:
Fats and Oils
• F.2.2: Predict the degree of crystallization
(solidification) and melting point of fats and
oils from their structure, and explain the
relevance of this property in the home and in
industry.
F.2:
Fats and Oils
• Melting point and hardness (degree of
crystallization) depend on
– Length of hydrocarbon chain
• Longer chain = greater molar mass = more vdW forces =
higher mp
– Degree of unsaturation
• More double bonds = crooked chains = less contact = fewer
vdW forces = lower mp
– Cis or trans conformation
• more cis = more crooked chains = less contact = fewer vdW
forces = lower mp
• more trans = less crooked chains = more contact = more
vdW forces (compared to cis) = higher mp
Triglycerides
• SATURATED (no double or triple bonds)
– Tend to be SOLIDS at room temperature
– Tend to come from animal products
– “Fat”
– Examples:
• Coconut oil
• Butter
• lard
Triglycerides
• Unsaturated (has one double or triple bond)
–
–
–
–
Tend to be LIQUIDS at room temperature
Tend to come from plant material
“Oil”
Examples
•
•
•
Olive oil
Canola oil
Peanut oil
• Polyunsaturated (has multiple double or triple bonds)
–
Example
• Sunflower oil
• Corn oil
• Fish oil