Transcript Slide 1

Sugars, Starches,
Gums and Fibers
Dr. Montville
Fall 2009
Outline
1. Uses in foods
2. Structure and function
3. “Artificial Sweeteners” Aspartame Smear
4. Starches, Pectins and Gums
5. Fiber and Diet
6. Metabolism of Sugars
7. Energy
8. Diet and Exercise
9. Video
10.Production of honey, sugar, maple syrup and
molasses
Uses of Carbohydrates in Foods
• Sweetener
• Structure
• Bulk
• Water Binding
• “Mouth feel”
• Color
• Nutrition
- Calories
- Soluble and Insoluble fiber
- Transit time, cholesterol bile binding
• Special uses of gums, starches and pectins: gelation,
viscosity, emulsification
Structure of Carbohydrates
“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 high-fructose 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).”
Sugar: 8 Little Known Facts
1. Today’s Consumption: Today, an average American consumes 2-3 pounds of sugar
each week. While at the end of the 19th century (1887-1890) the average American
consumed only 5 pounds per year.
2. A Continual Rise: Over the last 20 years, sugar consumption in the U.S has increased
by 26 pounds resulting in an average of 135 pounds of sugar consumed per person per
year
3. Hidden Culprits: Sugar consumption includes highly refined sugars that are
incorporated into many of the foods we eat ( bread, peanut butter, condiments,
sauces, ect.).
4. 4 Classes: 4 simple sugars (sucrose, fructose, honey and malts) are deemed
“harmful” to optimal health when long-term consumption is over 15% of calories
ingested. Why?
Sugar: 8 Shocking Facts (cont.)
5. Health Issues: Simple sugars have been documented to contribute to and/or
aggravate health problems including: asthma, mood disorders, mental illness, nervous
disorders, diabetes, heart disease, hypertension, gallstones and athritis.
6. Insulin Impacts: Sugar raises insulin levels, inhibiting the release of growth
hormones which depresses the immune system. Further, too much insulin promotes
the storage of fat, so that when you eat food high in sugar, you’re enabling rapid
weight gain and elevate triglyceride levels.
7. Degenerative Disease: Sugar has no real nutritional value and as a result, has a
deteriorating effect on the endocrine system, causing sugar to be one of the three
main causes of degenerative disease
8. Cancer Culprit: Turns out cancer’s preferred fuel is none other than glucose.
Controlling one’s blood glucose level through various means can be extremely
important to a cancer treatment program
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)
Low/No Calorie Sweeteners
- Reduce calorie intake
- Don’t affect insulin levels
- non-metabolize (except aspartame)
- non-nutritive
• Cyclamate – discovered in 1930 banned in 1970
• Saccharin – used since 1900’s, banned in 1977,
Reintroduced after congress lifted the ban with the
“Delaney Clause”
• Acesulfame K – approved in 1981, marketed under the names
Sunnette, NutraTaste
•Aspartame – approved in 1981, cannot be used in bakery products
• Sucralose – approved in 1998
Characteristics of Low/No Calorie Sweeteners
Aspartame
Saccharin
Sucralose
Composition
The amino acid aspartic acid
and phenylalanine
1,2-benzisothiazol-3(2H)one-1,1-dioxide
trichlororgalacto-sucrose
Caloric Value
4kcal/g
Calorie free
Calorie free
Metabolism/ Excretion
Upon digestion breaks down
to aspartic acid,
phenylalanine and small
amount of methanol
Not metabolized: excreted by
the kidneys unchanged
Not metabolized; excreted in
the feces and urine
ADI (acceptable daily
intake)
50mg/kg
15mg/kg or 1g/day
4mg/kg
Approximate consumption
as % of ADI
Less than 10%
Approximately 12%
Less than 20%
Labeling Requirements
Must bear statement that the
product contains
phenylalanine
Must bear statement that
saccharin has cause cancer in
lab. animals
none
Date of FDA approval
1981
1900 – since 1970’s interim
approval
1998
Food and Bev. Approved
for use in the U.S
Tabletop sweeteners,
beverages, processed foods
Tabletop sweeteners,
beverages, processed foods
Tabletop sweeteners,
beverages, processed foods
Stability
Loses sweetness when
exposed to high heat
Highly stable: can be used in
cooking and baking
Highly stable; can be used in
cooking and baking
Sugar and Sweeteners: a Molecular View
Scare tactics or concern? You decide
• When Nutrasweet is digested
it yield 10% methanol
• That is widely distributed
through your body and then
metabolized to
FORMALDEHYDE!!
• A glass of tomato juice has 6 times
more methanol than a can of soda
• Consumption for methanol toxicity
= 3033 cans of soda
• One extra can of sugar
sweetened soda per day can add
13 pounds per year
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
Structure of Starch
Amylose and Amylopectin
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 and Benefits 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
Possible Health Benefits
Obesity
Both
Replaces calories from fat, provides satiety, prolongs eating time
because of food chewiness
Constipation
Insoluble
Provides bulk and aids intestinal motility: binds bile acids
Diabetes
Soluble
May improve blood sugar tolerance by delaying glucose absorption
Hemorrhoids
Insoluble
Provides bulk and aids intestinal motility: binds bile acids
Colon Cancer
Insoluble
Speeds transit time through intestines and may 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
disease
“keeps you loose”
Decrease diabetes
Protects against colon
cancer
Protects against digestive
disorders
Glucose Metabolism
Glycemic index of foods
Low
Medium
High
Apples
bananas
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
Sucrose
Potatoes
Strawberries
Sweet corn
White bread
Glycemic index – the impact carbohydrates obtained from the above
sources will have on a persons blood glucoses levels
Insulin Response to Glucose Metabolism
The Effect of Diet on Physical Endurance
Brown Sugar Production
Sugar Cane
Shred
Press
Juice to Strainer
Raise pH with Lime
Residue (bagasse)
Add hot water and press
Bagasse (Usually used as fuel)
Heat
Supernatant
Allow to settle in
settling tank
Crystallize Clear
Juice under heat
and vacuum
Centrifuge and
wash
Brown
unpurified
sugar
White Sugar Production
Raw Sugar
Mixed with Saturate 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