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Disclaimer
This presentation was prepared using draft rules. There may be some changes in the final copy of the rules. The rules
which will be in your Coaches Manual and Student Manuals will be the official rules
Safety
Students must wear:
Closed shoes
Slacks or skirts that come to the ankles
Lab coat or lab apron
Indirect vent or unvented chemical splash proof goggles. No impact glasses or visorgogsare permitted
Long-Sleeved Shirt (if wearing a lab apron)
What Students MUST Bring
Impounded
6 Cupcakes with recipe card, clean cupcake liner, and team information
Notebook with experiments
Non-Impounded
Homemade viscometer
Standard curve
A writing instrument
What Students May Bring
Non-programmable Calculator
1 sheet of paper on which anything is acceptable
What Supervisors Will Supply
Everything the student will need
This may include:
Glassware
Reagents
Balances
Hot plates
Thermometers
Probes
Magnets
Stirrers
Main Focus Chemistry of Food
30% Experimental Notebook
10% Cupcakes
2% Density
2% Sensory
2% Crumbs
4% Nutritional Guidelines
60% Tasks and Experiments
How to prepare students
Experiment ideas
Resources
Chemistry of Food a. Identify the sources of and understand the role of lipids,
carbohydrates and proteins typically found in cookies, and use tests to identify these compounds, including the Benedict’s, Iodine and Brown Bag tests.
b. When given samples of sweeteners, use the Benedict’s test to identify reducing sugars.
c. When given samples of cupcake ingredients, use the Biuret test to identify and rank the ingredients by protein content.
d. When given formulations, processes, and finished cupcakes, identify the error in the cupcake formulation and/or process used.
e. Use standard labeling regulations to produce a label from information given.
f. Determine the moisture loss and density of cupcakes.
g. Identify leavening agents using chemical tests, and understand the role of the leavening agents in baked cupcakes.
Before your event
Research! Understand the science first
Experiments – three mandatory
Mixing method
Ingredient chemistry
Viscotester Production and Standard Curve
Ingredients
The right ingredients Liquids….
Lipids
Leavening agents
Flours
Sweeteners
Must understand WHY you are using the ingredient…what function does it provide?
Teams are limited to listed ingredients
List of Approved Ingredients
Liquids Lipids Leavening agents
Flours Sweeteners
Water, Whole
Milk (Cow or
Goat), Skim
Milk,
Buttermilk,
Almond Milk,
Soy Milk,
Coconut Milk,
Eggs, Egg
Substitute
Vegetable oils,
Shortening,
Butter
Margarines,
Chocolate
Baking powder
Baking soda
Cream of
tartar
FlavoringSalt
All purpose white flour
Bread flour
Cake flour
Whole wheat flour
Almond flour
Coconut flour
Corn Flour
Rice Flour
Sugar
Brown sugar
Honey
Sucralose
Aspartame
Vanilla
For State &
Nationals
Fructose
Powdered
Sugar
Each recipe must contain at least one egg or one egg substitute equivalent.
Carbohydrates
Carbohydrates Cox(H2O)y carbon along with
hydrogen and oxygen in the same ratio as water
Basic unit – monosaccharide
Multiple units – disaccharide (2)
trisaccharide (3)
oligosaccharide (2-10)
polysaccharide (>10)
Carbohydrates
Sugars
Monosaccharides
Glucose, Fructose
Disaccharides
Lactose (glucose and galactose) -milk
Maltose (glucose and glucose) -
Sucrose (glucose and fructose –table sugar
Reducing sugarsExamples: glucose, lactose, fructose
Non-reducing sugar contains no hemiacetal groups.
Example: sucrose
CarbohydratesPolysaccharides
Examples:
starch - glucose polymers, found in plants
cellulose –found in plant fibers, insoluble
Pectin-units are sugar acids rather than simple sugars, found in vegetables and fruits
Branched vs. linear
Starches are a mixture of branched (amylopectin) and linear (amylose) polysaccharides
Tests for carbohydrates
Benedicts test for sugars
Iodine test for starch
Positive Reaction
Benedict’s Test
The Benedict's test allows us to detect the presence of reducing sugars (sugars with a free aldehyde or ketone group). All monosaccharides are reducing sugars. Some disaccharides are also reducing sugars. Other disaccharides such as sucrose are non-reducing sugars and will not react with Benedict's solution. Starches are also non-reducing sugars.
The copper sulfate (CuSO4) present in Benedict's solution reacts with electrons from the reducing sugar to form cuprous oxide (Cu2O), a red-brown precipitate.
The final color of the solution depends on how much of this precipitate was formed, and therefore the color gives an indication of how much reducing sugar was present if a quantitative reagent was used.
With increasing amounts of reducing sugar the result will be: green yellow orange red
Iodine Test
The Iodine test is used to test for the presence of starch.
Iodine solution – Iodine is dissolved in an aqueous solution of potassium iodide -reacts with starch producing a deep blue-black color.
Although the exact chemistry of the color change is not known, it is believed that the iodine changes the shape of the starch to change the color
Lipids Present as fats extracted from plants or
animals (butter, vegetable oil) or as constituents of food (chocolate)
Contributions to foods: texture and flavor
Contain only Carbon, hydrogen and oxygen
Most common form for lipid in foods is as a triglyceride
What difference in texture would you see substituting vegetable shortening or vegetable oil for butter in the formulation?
Saturated Lipids (Fats)
Saturated fats have no double bonds in any of the fatty acid chains in the triglyceride hence it is saturated with hydrogen.
Considered not heart healthy
FoodLauricacid
Myristcacid
Palmitcacid
Stearic acid
Coconut oil 47% 18% 9% 3%
Butter 3% 11% 29% 13%
Dark chocolate
0% 0% 34% 43%
Eggs 0% 0.3% 27% 10%
Soybean oil 0% 0% 11% 4%
Unsaturated Fats (Lipids)
Have one (monounsaturated) or more (polyunsaturated) carbon chains
This means there are one or more double bonds in the chain
Lipids
http://www.wellsphere.com/healthy-cooking-article/butter-vs-shortening-in-baking/156136
Conversion between solid structure to a liquid state is called the melting point
How would changing the melting point of the lipid used change the cookie texture?
Brown Bag Test
Proteins
Proteins are made up of amino acids
essential and nonessential
Contains Nitrogen
Protein can be found in the flour, egg and milk as well as other ingredients.
Proteins
Biuret Test
The Biuret Reagent is made of sodium hydroxide and copper sulfate. The blue reagent turns violet in the presence of proteins, and the darker the purple color, the more protein is present.
Biuret’s Reagent is unstable, but can be mixed on the spot using NaOH & Benedicts
Leavening agents
Used to produce a gas that 'lightens' dough or batter.
used to raise baked goods.
water a leavening agent (pie crusts, some crackers)
air incorporated into batter (angel and sponge cakes)
expand when heated and cause the raising of the dough or batter when gas is trapped in matrix of gluten and starch from flour
Leavening agents Baking soda
-NaHCO3
Needs moisture plus an acid source such as vinegar, citrus juice, sour cream, yogurt, buttermilk, chocolate, cocoa (not Dutch-processed), honey, molasses (also brown sugar), fruits or maple syrup to react
used to neutralize acids in foods
around 4 times as strong as baking powder
can cause soapy flavor in high amounts
Leavening agents
Baking powder NaHCO3 plus acidifier(s) and drying agent (usually an
acid salt and cornstarch) can cause acidity and/or bitter off-flavor two acidifiers used in double acting to produce CO2 in
two steps Reacts when moistened and also reacts when heated double-acting is the only commercial baking powder
available today.
Standard Recipe
• 2 1/4 cups flour• 1 1/3 cups sugar• 3 teaspoons baking powder• 1/2 teaspoon salt• 1/2 cup shortening• 1 cup milk• 1 teaspoon vanilla• 2 large eggs
Effect of IngredientsBatch # Flour Leavening agent Sweetener Liquid Egg lipid Salt Vanilla
1 2 ¼ cups 3 tsps. baking powder 1 1/3 Cup 1 cup milk or sub.
2 large or substitute
none ½ tsp. 1 tsp.
2 2 ¼ cups 3 tsps. baking powder 1 1/3 Cup 1 cup milk or sub.
2 large or substitute
3 Tbsp oil ½ tsp. none
3 2 ¼ cups None 1 1/3 Cup 1 cup milk or sub.
2 large or substitute
3 Tbsp oil ½ tsp. 1 tsp.
4 2 ¼ cups 3 tsps. baking soda 1 1/3 Cup 1 cup milk or sub.
2 large or substitute
3 Tbsp oil ½ tsp. 1 tsp.
5 2 ¼ cups 3 tsps. baking powder 1 1/3 Cup 2 cup milk or sub.
2 large or substitute
3 Tbsp oil ½ tsp. 1 tsp.
6 2 ¼ cups 3 tsps. baking powder 2 1/3 Cup 1 cup milk or sub.
2 large or substitute
3 Tbsp oil ½ tsp. 1 tsp.
Mixing Technique
Incorporate ingredients
Hydrate dry ingredients
Experiment set 2 explores the best method to mix the batter
Standard Mixing
Preheat oven to 350 degrees. Line cupcake pans with paper liners.
Combine flour, sugar, baking powder, and salt in a large mixing bowl. Add shortening, milk, and vanilla. Beat for 1 minute on medium speed. Scrape side of bowl with a spatula.
Add eggs to the mixture. Beat for 1 minute on medium speed. Scrape bowl again. Beat on high speed for 1 minute 30 seconds until well mixed.
Spoon cupcake batter into paper liners until 1/2 to 2/3 full.
Bake for 20 to 25 minutes or until toothpick inserted in center comes out clean.
Cool 5 minutes in pans then remove and place on wire racks to cool completely.
Mixing TechniqueBatch # Step 1 Step 2 Step 3 Step 4
1 Mix dry ingredients
together
Add liquid
ingredients
Using spoon, stir
ingredients for
30 seconds
Add egg. Use spoon to
stir for 1 minute
2 Mix dry
ingredients
together
Add liquid
ingredientsPour into
blender or use
hand mixer and
blend or mix 2
minutes
Add egg. Use mixer or
blender to blend for 1
minute
3 Mix dry ingredientstogether
Add liquidingredients
Use whisk, stiringredients 1 minute
Add egg. Use whisk, stiringredients 2 minutes
Notebook Notebook keeping
30% of Regional score
All experimental data and documentation must be recorded in notebook
May be bound, spiral, or ring
Must securely hold all items
Don’t erase in lab notebook!
Document all references
Use pen
Notebook i. Experiment Name – 2 Points ii. Hypothesis – 4 points iii. Variables:
a. Controlled Variable(s) – 2 points b. Independent Variable(s) – 2 points c. Dependent Variable(s) – 2 points
iv. Materials (amount of each ingredient in grams or milliliters) – 4 points
v. Procedure – 10 points vi. Qualitative observations during the experiment (be sure to
include sensory score sheet) – 6 points vii. Quantitative observations during the experiment (Data
table, graphs-be sure to include nutritional calculations, viscosity testing, density, and crumb testing results) – 10 points
viii. Discussion of Results – 6 points ix. References – 2 points
Cupcake Use any combination of ingredients from the
approved list as well as physical parameter changes (temperature, cupcake lining materials, etc.) to formulate an ideal team cupcake. Teams may choose variables used in the first two experiments or use new variables. If a recipe from a cookbook or web site is used as a starting source, the source must be listed in the notebook.
Aiming for a density of 0.3 g/ml
Aiming for less than 0.3% of the mass of the cupcake to be left on liner or in crumbs when liner taken off
Must have nutrition food label
Viscotester
Made from 8 oz Styrofoam cup Heat 16 penny nail with tea candle for ~1 minute
(or until it gets too hot to hold) Punch hole from INSIDE into center bottom of cup Place tape over hole Time how long it takes for same amount of each
standard liquid to break flow as it leaves When determining how much fluid to use, keep a
couple of items in mind The larger the amount of fluid the less influence
reaction time will have on error. The amount of fluid the event supervisor is likely
to allow the team to have.
Standard Curve Use same amount of standard fluids to
calibrate
Time how long it takes to break stream
Standard Curve
Viscosity Students need to investigate viscosity of their
batters and compare to final results.
The resistance of a fluid to deformation.
Temperature dependent
*Dynamic or simple viscosity
Kinematic viscosity: ratio of viscosity/density
Shear viscosity – reaction to a shearing stress (pumping, spraying, etc.)
Must know general nomenclature
Measuring Density
Density Score Sheet
Students should measure the density of each of their experimental cupcakes and record
Suggested Density Suggested Score
.28-.329 5
.25-.279 or .32-.359 4
.21-.249 or .36-.389 3
.19-.209 or .319-.42 2
Less than .19 or greater than .42
1
Crumbs
Crumb Scoring
Students should score how much of their cupcakes stick to the paper or crumb for each of their experimental cupcakes
Percent of Crumbs Suggested Score
Less than .3% 5
.31-.4% 4
.41-.5% 3
.51-.6% 2
.61-.7% 1
Nutrition
Students will create a food label for their cupcakes properly indicating serving size, calories, amount fat, unsaturated fat, saturated fat, carbohydrates, sugars, fiber, and protein, as well as accompanying daily value percentages.
Students are NOT to be scored on how healthy the cupcake is, only on their ability to identify its role in a healthy diet.
Nutrition Calorie - amount of heat required to raise the temperature of 1
gram of water 1 degree Celsius.
Kilocalorie (1000 calories) is the unit commonly used to represent energy values of foods -or Calorie with a C instead of a c
Not all carbohydrates (or fats, or proteins) yield the exact same amount of energy when burned in a calorimeter, so common averages from studies (in kcal/g) are used
Carbohydrates average 4.1 kcal/gram in a bomb calorimeter, are about 98% digestible and yield 4 kcal/g when consumed
Proteins average 5.7 kcal/g in a bomb calorimeter, are not as easily digested and yield an average of 4 kcal/g when consumed
Lipids average 9.5 kcal/g in a bomb calorimeter, are 95% digested and yield an average of 9 kcal/g when consumed
Fats (lipids) are the most concentrated source of food calories
Carbohydrates are the cheapest source of calories, proteins the most expensive
Fiber
Foods not digested by human digestive system
Two types
Soluble Fiber-helps regulate blood sugar
Found in Oats & Oat Bran, some Fruits & vegys
Insoluble Fiber-helps clean out colon
Found in whole wheat, some fruit skins and vegys
Nutritional labeling
1) Fill in the following blanks.
a) There are ___ Calories/gram of fat.
b) There are ___ Calories/gram of carbohydrate
c) There are ___Calories/gram of protein
d) There are ___Calories/gram of water
2) Use the nutritional label given for information to
answer the following questions:
a) Calculate the Calories in one serving of this
product.
(1) Calories from Fat
(2) Calories from Protein
(3) Total Calories in one serving
b) What percent of the carbohydrate Calories come
from fiber?
c) If the daily value of iron is 18 mg per day, calculate
the amount (in mg) of iron in one bar of this
product.
Nutrition Scoring
The labels will be scored as follows:
i. Creative Cupcake name (5 points)
ii. Ingredient List in correct order (15 points)
iii. Nutritional Facts in correct order (15 points)
iv. Package Weight (10 points)
v. Company (team) Name and Address in the correct location (5 points)
vi. Label Information matches notebook (10 points)
Sensory Score SheetAttribute Score (Circle for each attribute listed)
Flavor
Aroma 1
Terrible
2 3
Average
4 5
Very Pleasing
Starch
1
Raw or burned
2
Under or over
cooked
3
Slightly under or
over cooked
4
Pleasingly cooked
5
Very Pleasingly
cooked
Dairy/Milky
1
Spoiled
2
Moderate off-flavor
3
Slightly off flavor
4
OK
5
Pleasant
Sweetness
1
Way too much or
too little
2
Moderately too
much or too little
3
Slightly too sweet
or too tart
4
About right
5
Perfect sweetness
Vanilla
1
Way too much or
not enough
2
Moderately too
much or too little
3
Slightly too much
or too little
4
About right
5
Excellent
Texture
Surface
1
Really rough
2
Somewhat rough
3
Moderately rough
4
Slightly smooth
5
Smooth
Moisture
1
Dry
2
Moderately dry
3
Somewhat dry
4
Somewhat moist
5
Moisture just right
Cohesiveness
1
Really gummy
2
Somewhat gummy
3
Slightly gummy
4
Falls apart easily
5
Just right
Stickiness
1
Really sticky
2
Moderately sticky
3
Somewhat sticky
4
Slightly sticky
5
Just right
Circle any of the
following if
present
Sour Bitter Astringent Gritty
Oxidized (paint)
flavor
State and Nationals Icing – emulsion mixture of two or more
immiscible (un-blendable) liquids
Basic Recipe
2 cups confectioners' sugar, sift before measuring-or sugar substitute
1 1/2 tablespoons butter, soft or butter substitute
1/2 teaspoon vanilla extract
1/4 teaspoon salt
3 to 4 tablespoons milk or milk substitute
Combine all icing ingredients in small mixing bowl. Stir until smooth and well blended. Adjust for spreading consistency if necessary, adding more milk or more confectioners' sugar.
Advanced Experiments
Document at least 4 additional experiments in the laboratory notebook involving the icing
Experiments should include varying the ingredients as well as the quantities of the ingredients.
Researchers will need to document how easily the icing spreads, how well it holds its shape, and how long it takes to dry out as well as evaluating the sensory experience
Resources
For Event Supervisors
http://mypage.iu.edu/~lwoz/socrime/index.htm
For Lesson Plans for classroom use
http://mypage.iu.edu/~lwoz/socrime/index.htm
Questions
Thank You
Time to Play
We can make viscotesters
We can simulate a standard curve data collection
We can find the viscosity of a batter
We can find the density of muffins (substitute cupcakes)
We can work with some tests from a simulated test.
It is your option
