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Fat StructureFatty 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.
Polyunsaturated > monosaturated
“Attempt” to hydrogenate 4 cis double bonds succeeds with 2, leaves one alone, creates one trans double bond.
Trans fats “look” more like saturated fats.Trans fats “look” more like saturated fats.
“Partially hydrogenated” fats.
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.
Outline1. Video2. Uses in foods3. Structure and function4. “Artificial Sweeteners” Aspartame Smear5. Starches, Pectins and Gums6. Fiber and Diet7. Metabolism of Sugars8. Energy9. Diet and Exercise10.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
High Fructose Corn Syrup, What is it? How is it made? Is it natural? Is it good for you?
Glucose
Glucose
Glucose
Glucose
Glucose
GlucoseGlucose
Fructose GlucoseGlucoseGlucoseGlucoseGlucose
Glucose
Glucose
Fructose
Fructose
Fructose
Sucrose Starch
High Fructose Corn Syrup 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.
Attributes of High Fructose Corn Syrup
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.
“Sugar is Back on Food Labels, This time as a Selling Point” The New York TimesMarch 21, 2009By 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).”
•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
Sugar alcohols*
Sorbitol 0.5
Mannitol 1
Xylitol 1
Artificial Sweeteners
Cyclamate Banned in U.S “Delaney Clause”
Saccharin 500
Aspartame 100
Sucralose 600
Acesulfame K 200
*bind water, laxative effect, gassy (caloric)
0.2 Cal/g
Stevia from plant extract 300 times sweeter than sucrose
Truvia based on Stevia
Neotame based on Nutrasweet 7,000 – 13,000 sweeter
Polyunsaturated > monosaturated
“Attempt” to hydrogenate 4 cis double bonds succeeds with 2, leaves one alone, creates one trans double bond.
Trans fats “look” more like saturated fats.Trans fats “look” more like saturated fats.
“Partially hydrogenated” fats.
Hydrogen bonding and solubility in water“Hydrogen
bonding” is nothing more than the attraction of positive and negative.
Fat StructureFatty 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 SodasComponent Rec’d Amt Cal/
gCal Couch
potatoRunner
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 0 -800 Cal
Total Cal = 2,154 HFCS Bad
Total Cal = 1,334 HFCS Good
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 StarchesFood 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 StarchAmylose = 30% of the starch, tightly packed, less digestible, insoluble in water.
Amylopectin = 70% starch, soluble in water, many endings, crystalline
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
GumsGums - 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
Sources of FiberFoods 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 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 Cancer
Insoluble Speeds transit time through intestines and may protect against prolonged exposure to carcinogens
Carbohydrate CharacteristicsSimple Sugars and Starches
Soluble Complex Fibers
Insoluble Complex Fibers
Digested like glucose Nondigestible
High glycemic indexProvokes 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
Glycemic index of foods
Low (Used slowly) Medium High (Used rapidly)
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 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 :
White Sugar ProductionRaw Sugar
Mixed with saturated sugar syrup
Centrifuge to remove impurities*
Dissolve water and raise pH
Heat to 180°F
Filter through diatomaceous earth and charcoal
Package
Screen for size
Dry
Centrifuge and Wash
Crystallize in Vacuum Pans
Supernatant
*“Impurities” become molasses