Fat Structure
Fatty acids are either
saturated, monounsaturated
(contain one C=C double
bond) or polyunsaturated
(contain two or more C=C
double bonds)
Saturated fatty acids stack
closely and are more solid.
Unsaturated fatty acids are
more fluid. “Hydrogenating”
unsaturated fatty acids
makes them more rigid.
Cis and trans hydrogens
Trans fats “look” more like
saturated fats.
“Partially hydrogenated” fats.
Trans fats “look” more like saturated fats.
Polyunsaturated > monosaturated
“Attempt” to hydrogenate 4 cis
double bonds succeeds with 2,
leaves one alone, creates one
trans double bond.
Talk Show Schlock – Apples, arsenic, Alar
Timely vs
“on topic”
Transition: Top Ten Lessons I Learned In College
10. Success is 1% inspiration and 99% cramming the night before the
exam.
9. Roommates can be pretty harsh if you're still sleeping with your Big
Bird doll.
8. Laughing at the professor’s jokes brings up the curve.
7. The best way to learn biology is in the woods behind Heylar House.
6. On Microsoft Word, if you drag down the format window and click on
paragraph, adjusting the line spacing can make your papers look a lot
longer.
5. Do your laundry every six months, whether you need it or not, (or
take it home and have Dad do it.)
4. Do I have to think of another?
3. Um...sorry, I'm drawing another blank.
2. My parents wasted about 80 grand.
1. If you major in some lightweight field, goof off and get bad grades,
you could become rich like that dropout Bill Gates.
Sugars, Starches,
Gums and Fibers
Outline
1. Video
2. Uses in foods
3. Structure and function
4. “Artificial Sweeteners” Aspartame Smear
5. Starches, Pectins and Gums
6. Fiber and Diet
7. Metabolism of Sugars
8. Energy
9. Diet and Exercise
10.Production of honey, sugar, maple syrup and
molasses
Uses of Carbohydrates in Foods
• Sweetener
• Structure
• Bulk (sugar substitutes)
• Water Binding
• “Mouth feel”
• Color
• Nutrition
- Calories
- Soluble and Insoluble fiber
- Intestinal transit time, cholesterol bile binding
• Special uses of gums, starches and pectins: gelation,
viscosity, emulsification
Structure of Carbohydrates
Cartoon Chemistry
High Fructose Corn Syrup, What is it? How
is it made? Is it natural? Is it good for you?
Glucose
Glucose
Fructose
Glucose
Glucose
Glucose
Starch
Sucrose
Fructose
Glucose
Glucose
Glucose
Glucose
Glucose
Glucose
Fructose
Glucose
Fructose
Corn Syrup
Glucose
Glucose
High Fructose Corn Syrup
Attributes of High Fructose Corn Syrup
•Its liquid form and dust-free nature make it easy to
handle.
•The glucose and fructose in HFCS contribute to the
desirable brown colors in baked.
•HFCS has greater water binding capacity than sucrose.
•HFCS has sweetening, thickening, and water binding
properties and can balances tartness.
• HFCS is more stable than sucrose in acid products.
• HFCS is more stable than some artificial sweeteners.
•Its sweetness can be manipulated by varying the
fructose: glucose ratio.
•HFCS is not as likely as sucrose to form crystals, which
can impart a “gritty” defect.
Is HFCS healthy?
HFCS has the same 4 Cal/g as sucrose.
HFCS is not the culprit for obesity.
The over consumption of calories in sweetened beverages
plays a large role in the obesity problem. Sedentary life
style and lack of exercise also play a large role.
Excess calories can come from sucrose, corn syrup, high
fructose corn syrup or fat.
Over consumption of calories is not healthy.
Guess the calories
Guess the calories
1,443 Calories
1,500 Calories
Law suits against
Snapple and Arizona
“Not natural”
What is the legal definition of a
natural ingredient?
“Sugar is Back on Food Labels, This
time as a Selling Point”
The New York Times
March 21, 2009
By Kim Severson
- The quiet rivalry between sugar and highfructose corn syrup appears to have a winner.
- “ The first lady, Michelle Obama, has said she
will not give her children products made with it
(high-fructose corn syrup).”
It’s a choice, market segmentation
•HFCS consumption is at a 20 year low (37 lbs per person, 44 lbs for sucrose).
•“Sugar is sugar, HFCS has been highly disparaged and highly
misunderstood.”
•Analogy to the renaming of other foods – “Rapeseed oil”.
•Even CSPI (and AMA) says sugar and HFCS are the same and have same
health effect.
•“Corn sugar” more easily understood and eliminates the negative connotation.
Relative sweetness of sweeteners
“Sugars”
Sucrose
1
Fructose
1.7
Glucose
0.7
Lactose
0.16
Maltose
0.32
Galactose
0.32
Artificial Sweeteners
Cyclamate
Banned in U.S
“Delaney Clause”
Saccharin
500
Aspartame
100
Sucralose
600
Acesulfame K
200
Sugar alcohols*
Sorbitol
0.5
Mannitol
1
Xylitol
1
*bind water, laxative effect,
gassy (caloric)
0.2 Cal/g
Stevia
from plant extract
Truvia
based on Stevia
Neotame
based on Nutrasweet
300 times sweeter than sucrose
7,000 – 13,000 sweeter
Sugar and Sweeteners: a Molecular View
A SHORT REVIEW
Trans fats “look” more like
saturated fats.
“Partially hydrogenated” fats.
Trans fats “look” more like saturated fats.
Polyunsaturated > monosaturated
“Attempt” to hydrogenate 4 cis
double bonds succeeds with 2,
leaves one alone, creates one
trans double bond.
Hydrogen bonding and solubility in water
“Hydrogen bonding” is
nothing more than the
attraction of positive and
negative.
Structure of sucrose
Fat Structure
Fatty acids are either
saturated, monounsaturated
(contain one C=C double
bond) or polyunsaturated
(contain two or more C=C
double bonds)
Saturated fatty acids stack
closely and are more solid.
Unsaturated fatty acids are
more fluid. “Hydrogenating”
unsaturated fatty acids
makes them more rigid.
Carbohydrates



Structure
Importance of glucose
Relative sweetness





Lo/no cal sweeteners
High fructose corn
syrup
No definition of
“natural”
My nuanced opinion
of “Is HFCS good or
bad?” It all depends…
“Bias”
A Tale of Four Sodas
Component
Rec’d Amt
Cal/
g
Cal
Carbohydrate
120 g
4
480
Protein
56 g
4
224
Fat
30% of total
9
300
Required “Nutrient Calories”
1004
“Elective” Calories
540
Total Caloric Requirement
1,544
Add 4 cans soda (150 Cal/can)
600
Activity
Couch
potato
Runner
0
-800 Cal
Total Cal = 2,154 Total Cal = 1,334
HFCS Bad
HFCS Good
Discuss web rants
-Dr Oz - more
-Best and worst sugars- new
Other items:
•How can you know?
•Questions about the extra credit?
•Questions about lipids, or carbs
thus far?
•Comments on the “Knowledge
Assessment Opportunity”
•Attendance
Function of Starches
Food
Function
Benefits
Pies, tarts, fillings
Stabilize and thicken
Resistant to weeping
Instant puddings
Instant thickening
Creamy texture,
smoothness and fast
meltaway
Gravy and sauces
Thickening without
lumping
Texture and cling
Jelly gums
Setting and gelling agent
Clarity, easy processing
Baked or fried puffed
snacks
Volume control, crispness No need for cooking
during forming process
Breakfast cereal
Texture enhancement
Excellent expansion and
bowl life
French fries
Form, crisp coating,
internal binder
Crispier more appetizing
product
Amylose and Amylopectin
– Two forms of starch
Structure of Starch
Amylose = 30% of the starch,
tightly packed, less digestible,
insoluble in water.
Amylopectin = 70%
starch, soluble in water,
many endings, crystalline
Starch retrodegration
Gluten, good or bad?
Selling point?
Survey:
Do you think gluten is “bad”?
Are you more likely to buy a product advertized as “gluten free”?
Gluten






Protein from wheat,
barley, and rye (rice and
corn different)
Associated with starch
Gliadin + gluteline
Important global protein
source
Plasticity, shape,
chewiness
Celiac disease < 1.0 % of
population
Gums
Gums - hydrocolloidal suspensions that don’t gel, aren’t soluble,
but bind lots of water. Most important are non digestible soluble
fiber.
Source
Gum
Seeds
Guar and Locust bean
Plants
Arabic (soluble in cold
water)
Microbes
Xanthan and gelan
Sea weed
Alginate, carrageen, agar
Chemical synthesis
micro-crystalline
cellulose, carboxy methyl
cellulose
Soluble and Insoluble Fibers
Sources of Fiber
Foods Rich in Insoluble Fiber
Foods rich in Soluble
Apples
Citrus fruits
Beets
Oatmeal
Cauliflower
Potatoes
Seeds
Cherries
Nuts
Corn
Green beans/peas
Seeds
Wheat bran
Barley
Health
problem
Fiber
type
Obesity
Both
Possible Health Benefits
Replaces calories from fat, provides satiety,
prolongs eating time because of chewiness
Constipation Insoluble Provides bulk and aids intestinal motility:
binds bile acids
Diabetes
Soluble May improve blood sugar tolerance by
delaying glucose absorption
Hemorrhoid Insoluble Provides bulk and aids intestinal motility:
binds bile acids
Colon
Insoluble Speeds transit time through intestines and may
Cancer
protect against prolonged exposure to
carcinogens
Carbohydrate Characteristics
Simple Sugars and
Starches
Soluble Complex
Fibers
Insoluble Complex
Fibers
Digested like glucose
Nondigestible
High glycemic index
Provokes insulin
response
No insulin response
Provides 4cal/g
No calories
May lower cholesterol Decreases intestinal
transit time
Decreases risk of heart “keeps you loose”
disease
Decrease diabetes
Protects against colon
cancer
Protects against
digestive disorders
Glucose Metabolism
Glycemic index of foods
Low (Used slowly)
Apples
Medium
bananas
High (Used rapidly)
Carrots
Beans
High-fructose corn
syrup
Dry dates
Chickpeas
Honey
Glucose
Grapefruit
Ice cream
Instant white rice
Green leafy
vegetables
Oatmeal cookies
Jelly beans
Soy milk
Strawberries
Sucrose
Sweet corn
Potatoes
White bread
Glycemic index – the impact on blood glucose levels
The glycemic index, glycaemic index, or GI is a measure of the
effects of carbohydrates on blood sugar levels. Carbohydrates that
break down quickly during digestion and release glucose rapidly into
the bloodstream have a high GI; carbohydrates that break down more
slowly, releasing glucose more gradually into the bloodstream, have a
low GI.
A lower glycemic response usually equates to a lower insulin demand
but not always, and may improve long-term blood glucose control[2]
and blood lipids.
The glycemic index of a food is defined as the area under the two
hour blood glucose response curve (AUC) following the ingestion of
a fixed portion of carbohydrate (usually 50 g). The AUC of the test
food is divided by the AUC of the standard (either glucose or white
bread, giving two different definitions) and multiplied by 100.
The current validated methods use glucose as the reference food,
giving it a glycemic index value of 100 by definition. GI values can be
interpreted intuitively as percentages on an absolute scale and are
commonly interpreted as follows :
Insulin Response to Glucose Metabolism
The Effect of Diet on Physical Endurance
White Sugar Production
Raw Sugar
Mixed with saturated sugar syrup
Package
Centrifuge to remove impurities*
Screen for size
Dissolve water and raise pH
Dry
Heat to 180°F
Centrifuge and Wash
Supernatant
Filter through diatomaceous earth
and charcoal
Crystallize in Vacuum Pans
*“Impurities” become molasses
“The three moles.”