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					The skinny on artificial sweeteners and weight gain
Presented by Ann Cohen and Jessica Kovarik

Taste: how
Groups of taste cells on papillae (bumps) Chemical binds with taste cell
 Depolarization of nerve fibers  action potential to brain  Adaptation of nerve transmittion

Taste: what and why
5 tastes: salty, sour, bitter, umami, and sweet
 No longer taste ‘zones’

Taste and survival
 Avoid bitter  Seek out sweet

Sweetness abounds
Sugar = Carbohydrates
 Simple and complex
Main source of energy (4 calories per gram) Occur naturally in foods and added to foods

Simple sugars:
 Sucrose = glucose + fructose
Table sugar

 Lactose = glucose + galactose
Dairy

 Maltose = glucose + glucose
Germinating grains

Sweetness abounds
Other natural sweeteners:
 Honey, molasses, maple syrup, corn syrup, high fructose corn syrup  Sugar alcohols or polyols, such as mannitol, sorbitol, isomalt

Sweet energy
Nutritive sweeteners
 Contain calories  Honey, HFCS, table sugar, maple syrup, etc.

Nonnutritive sweeteners
 Reduced or no calories  Sugar alcohols and artificial sweeteners

Getting 1+1=1: artificial sweeteners
Low-calorie sweeteners
 Sweet taste with fewer or no calories  Food and Drug Administration approval

Six intense, low-calorie sweeteners:
 Saccharin – Sweet’N Low/Sugar Twin  Acesulfame potassium (Ace-K)  Aspartame  Neotame  Sucralose - Splenda  Tagatose

Getting 1+1=1: artificial sweeteners
Sucralose aka Splenda
 Heat stable = use for baking  3 chlorine atoms instead of hydroxyl groups  600 times sweeter than sugar  Created from sugar, so tastes similar to sugar
Body not able to break it down

Getting 1+1=1: artificial sweeteners
Stevia
 Natural sweetener extracted from plants  Not FDA approved, so sold as a supplement  Body cannot metabolize, so no calories  Studies inconclusive about safety: some show no adverse reactions, others suggest smaller offspring

Rumor has it sugar causes…
Cavities
 Contact time of bacteria, not type of food leads to decay  i.e.: bread can be worse than caramel

Hyperactivity
 No scientific research to support  Is it the sugar or the environment?  May have a calming affect

Rumor has it sugar causes…
Diabetes
 Important to monitor to control diabetes

Obesity
 Energy imbalance leads to weight gain

High fructose corn syrup
What is it?
 Corn starch converted to glucose  Glucose isomerized by enzymes to 42% or 55% fructose  Named ‘high fructose’ to distinguish from glucose corn syrup  Sweet taste, low cost, easy to use resulting in wide use
Soft drinks, fruit drinks, baked goods, processed foods, dairy products

High fructose corn syrup
Media claims HFCS causes obesity
 Increase in obesity coincides with increased HFCS use
i.e.: added to soft drinks in early 1980s But obesity also problematic in countries where HFCS use is not as prevalent

High fructose corn syrup
Media claims HFCS causes obesity
 Fructose converts to fat easier than glucose
Absorbed at different site by different mechanism Any fructose metabolized same
 HFCS vs. sucrose

Fructose metabolized differently than glucose once in the cell

Fructose verses glucose
Insulin
 Glucose causes insulin to be released  Fructose does not stimulate insulin release

Satiety
 Glucose used by the brain and helps sense satiety

Fructose verses glucose
Leptin
 Increased by insulin release  Increased leptin  decreased food intake
Controls appetite

 Glucose  insulin release increased leptin  decreased food intake

High fructose corn syrup verdict
No evidence to support HFCS contributes significantly to obesity Energy imbalance leads to obesity

Sweeteners and obesity
Artificial sweeteners may cause disruption in body’s ability to gauge caloric density Body appears to gauge calories based on thickness
 Semi-solid and liquid foods/beverages inhibit body’s ability to accurately compensate

Sweeteners and obesity
Obesity has continued to rise as use of artificial sweeteners has risen Multi-factorial problem
 Energy balance: energy in and energy out  Sugar = calories
Excess calories (and inactivity) = weight gain Weight balance = energy out vs. energy in

Laboratory ideas
Tooth Decay
 Explores the effect of various liquids on decaying teeth

Sugar composition of beverages
 Determine the sugar content of various beverages
All the same type: such as juice or soft drinks Compare different types: such as milk, juice, soft drinks, water, etc.

Experiments with soft drinks
 http://www.eepybird.com/science1.html

Resources for teachers
http://science.nsta.org/enewsletter/200606/member_high.htm http://www.free-science-fair-projects.net/
 http://www.free-science-fairprojects.net/science-fair-projects-on-toothdecay.html

http://www.splenda.com/ http://www.eepybird.com/science1.html

References
         Physiology of taste. Accessed June 12, 2006 from http://biology.about.com/library/organs/blpathodigest2.htm Schorin MD. (2005). High fructose corn syrups, part 1. Nutrition Today, 40(6), 248-252. Hein GL, Lineback DR, Storey ML, & White JS. (2005). Highs and lows of high fructose corn syrup. Nutrition Today, 40(6), 253-256. Science fair projects on tooth decay. Accessed June 12, 2006 from http://www.freescience-fair-projects.net/science-fair-projects-on-tooth-deecary.html Juices. Accessed May 31, 2006, from http://www.selah.k12.wa.us/MS/SciProj98/8TH/tarrahw/JUICES.HTML Which beverage contains the most sugar? Accessed May 31, 2006, from http://www.selah.k12.wa.us/MS/SciProj98/6TH/Sugar/COURTNEYA.HTML Duyff RL. (2002). Complete food and nutrition guide. 2nd ed. Hoboken, New Jersey: Wiley. Physiology of taste. Accessed June 13, 2006, from http://biology.about.com/library/organs/blpathodigest2.htm Study: artificial sweeteners may disrupt body’s ability to count calories. (2004). Purdue News. Accessed June 13, 2006, from http://www.purdue.edu/UNS/html4ever/2004/040629.Swithers.research.html


				
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