1. 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.

2. 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

3. Carbohydrates Carbohydrates Basic unit – monosaccharide
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)

4. Carbohydrates Sugars Reducing sugars Monosaccharides
Examples: glucose, lactose, fructose
Non-reducing sugar contains no hemiacetal groups.
Example: sucrose
Sugars
Monosaccharides
Glucose, Fructose
Disaccharides
Lactose (glucose and galactose) -milk
Maltose (glucose and glucose) -
Sucrose (glucose and fructose –table sugar

5. Carbohydrates Polysaccharides Examples: Branched vs. linear
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

6. Tests for carbohydrates
Benedicts test for sugars
Iodine test for starch
Positive Reaction

7. 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

8. 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

9. 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?

10. 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
Food
Lauric acid
Myristc acid
Palmitc acid
Stearic acid
Coconut oil
47%
18% 9% 3%
Butter
11%
29%
13%
Dark chocolate 0%
34%
43%
Eggs
0.3%
27%
10%
Soybean oil 4%

11. Unsaturated Fats (Lipids)
Have one (monounsaturated) or more (polyunsaturated) carbon chains
This means there are one or more double bonds in the chain

12. Lipids
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

13. 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.

14. 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

15. 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

16. 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

17. 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.

18. 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

19. Effect of Ingredients Batch # 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
3 Tbsp oil 3
None 4
3 tsps. baking soda 5
2 cup milk or sub. 6
2 1/3 Cup

20. Mixing Technique Incorporate ingredients Hydrate dry ingredients
Experiment set 2 explores the best method to mix the batter

21. 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.

22. Mixing Technique Batch # Step 1 Step 2 Step 3 Step 4 1 Mix dry
ingredients
together
Add liquid
Using spoon, stir
ingredients for 30 seconds
Add egg. Use spoon to stir for 1 minute 2
Mix dry ingredients together
Pour into blender or use hand mixer and blend or mix 2 minutes
Add egg. Use mixer or blender to blend for 1 minute 3
Use whisk, stir
ingredients 1 minute
Add egg. Use whisk, stir
ingredients 2 minutes

23. 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.

24. Standard Curve Use same amount of standard fluids to calibrate
Time how long it takes to break stream

25. Standard Curve

26. 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

27. Measuring Density

28. Less than .19 or greater than .42
Density Score Sheet
Students should measure the density of each of their experimental cupcakes and record
Suggested Density
Suggested Score 5 or 4 or 3 or 2
Less than .19 or greater than .42 1

29. 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

30. 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

31. Nutritional labeling Fill in the following blanks.
There are ___ Calories/gram of fat.
There are ___ Calories/gram of carbohydrate
There are ___Calories/gram of protein
There are ___Calories/gram of water
Use the nutritional label given for information to answer the following questions:
Calculate the Calories in one serving of this product.
Calories from Fat
Calories from Protein
Total Calories in one serving
What percent of the carbohydrate Calories come from fiber?
If the daily value of iron is 18 mg per day, calculate the amount (in mg) of iron in one bar of this product.

32. Sensory Score Sheet Attribute Score (Circle for each attribute listed)
Flavor
Aroma 1
Terrible 2 3
Average 4 5
Very Pleasing
Starch
Raw or burned
Under or over cooked
Slightly under or over cooked
Pleasingly cooked
Very Pleasingly cooked
Dairy/Milky
Spoiled
Moderate off-flavor
Slightly off flavor OK
Pleasant
Sweetness
Way too much or too little
Moderately too much or too little
Slightly too sweet or too tart
About right
Perfect sweetness
Vanilla
Way too much or not enough
Slightly too much or too little
Excellent
Texture
Surface
Really rough
Somewhat rough
Moderately rough
Slightly smooth
Smooth
Moisture
Dry
Moderately dry
Somewhat dry
Somewhat moist
Moisture just right
Cohesiveness
Really gummy
Somewhat gummy
Slightly gummy
Falls apart easily
Just right
Stickiness
Really sticky
Moderately sticky
Somewhat sticky
Slightly sticky
Circle any of the following if present
Sour
Bitter
Astringent
Gritty
Oxidized (paint) flavor