Download Food Science Mentor Science Olympiad Invitational 07/08 Names

Food Science
Mentor Science Olympiad Invitational 07/08
Names: _____________________________________________________________
School: ___________________________________________
Team Number: ___________________
Cleaned up well: __________
Followed all safety guidelines: _________
FINAL SCORE: ___________
Rank: ___________
PLEASE READ:
 Be Safe!! Keep your Goggles On or points will be deducted.
 Clean up! Be sure the lab station returns to its original conditions or points will
be deducted.
 You may separated pages and work on experiments in any order. Be sure the
packet gets put back together in the correct order.
 GOOD LUCK!! 
WEAR YOUR GOGGLES AND APRON THROUGH OUT THE DURATION OF THIS EVENT!!!
Exp #1: The Complete Marshmallow Analysis
PART 1: Calories in a Marshmallow
You will use a soda can calorimeter to determine the amount of Calories in a marshmallow. The general
procedure for this process is outlined below. On your answer sheet, please construct a detailed data table
summarizing any measurements you’ve made.
SINCE YOU WILL BE USING FIRE IN THIS LAB, PLEASE USE CARE!!! TIE BACK LONG HAIR
IN ADDITION TO WEARING GOGGLES AND APRONS.
MATERIALS AVAILABLE TO YOU:
Calorimetry set up (can, stirring rod, ring stand and ring, large spoon)
100 mL graduated cylinder
Electronic balance
Grill lighter
Stirring rod
Thermometer
Marshmallows
GENERAL PROCEDURE:
- Set up the soda can calorimeter as you see in the picture to the right.
- Mass about 3 mini marshmallows.
- Pour 90 – 100 mL of water in the can. Record.
- Record temperature of water.
- Ignite marshmallows from base. The flaming marshmallows
should be no more than 2 cm from base of can. Swirl can gently while
marshmallow burns. You may keep the thermometer in can.
- Record highest temperature once marshmallows go out.
- Mass remains of marshmallows.
CLEAN UP:
- Empty water from can and wipe ash residue from can.
- Return station to exactly how you found it.
PART 2: Macromolecule Composition of a Marshmallow
Conduct the basic macromolecule tests on a marshmallow to determine its composition.
GENERAL PROCEDURE:
1. Place a marshmallow in about 20 mL of water in a small beaker. Swirl the marshmallow around to get
it to dissolve. It won’t ALL dissolve.
2. Use this solution to conduct the following tests:
TEST 1: Benedict’s Test
1. Add one full squirt of marshmallow solution into a test tube.
2. Add 4 drops of Benedict’s reagent. Tap test tube to mix.
3. Heat the test tube for 3 minutes in the provided boiling water bath. PLEASE BE CAREFUL!!!
4. Remove the tube, handling them from the rim and record the results on the data table.
TEST 2: Iodine Test
1. ½ fill a well on the well plate with marshmallow solution.
2. Add 2 drops of iodine solution to well and mix with toothpick.
3. Record results on data table.
TEST 3: Biuret Test
1. ½ fill a well on the well plate with marshmallow solution.
2. Add 2 drops of Biuret test reagent to well and mix with toothpick.
3. Record results on data table.
PART 3: % Air in a Marshmallow
Obviously, a good percentage of a marshmallow is nothing more than air. In this part, you will
experimentally determine the % air in a marshmallow.
1. Using the formula, Vcylinder =  r2h, and a ruler to calculate the volume of a marshmallow.
2. Put the marshmallow in the syringe and squeeze the syringe to remove all of the air. Measure the new
volume of the de-aired marshmallow. The units on the syringe are also cm3.
3. Calculate the % Air by volume in a Marshmallow.
Exp #2: % Sugar in Beverages
Almost all soft drinks that are not milk-based (Coke, Sprite, Kool-Aid, etc) are essentially sugar solutions with small
amounts of additives for flavoring and color. You will determine the density of different sugar solutions and make a
graph of density vs % sugar. This is called a calibration curve. You will use the calibration curve and the density of
each beverage to determine the % sugar in each beverage you test.
PROCEDURE:
Measure and record the mass and volume of a 0%, 5%, 10%, 15% and 20% sucrose solution. Do the same for the
Coke, Diet Coke and Coke Zero samples.
-
Place a 250 mL beaker on the electronic balance. You will add all of your solutions to this beaker to determine
their masses. Push tare in between each measurement.
Use a 10 mL pipet to precisely measure the volume of 10.00 mL of solution. Be sure to extract ALL of the
liquid from the pipet.
Dry the outside of the pipet in between each new solution.
Dump the solutions down the drain when you are finished.
Exp #1: The Complete Marshmallow Analysis (48 pts total)
PART 1: Calories in a Marshmallow
DATA TABLE:
1. Record measurements from experiment here. Be sure to record digits to greatest accuracy possible.
(4 points)
Mass of Marshmallows:
Volume of water used:
Initial Temperature of water:
Final Temperature of water:
CALCULATIONS:
1. In this calorimetry experiment, we are making the assumption that the heat lost by the marshmallows was gained by the water.
What is the formula you should use to calculate the heat released by the marshmallows, qmarshmallows. (2 pts)
2. Use the formula above, and calculate the Calories in your marshmallow sample. Assume that the heat capacity of the
calorimeter is negligible. SHOW AND LABEL YOUR WORK VERY CLEARLY. (2 pts)
** Density of water = 1.00 g/mL
** Specific heat of water = 1.00 cal/g.oC
** 1,000 calories (cal) = 1 kilocalorie (kcal) = 1 Calorie (Cal)
3. Calculate the Calories released per GRAM of marshmallow.
(2 pts)
4. Using the Nutrition Facts label from the peanut container, calculate the actual heat release per gram of marshmallow. (2 pts)
Nutrition Facts
Serving Size 2/3 cup (30 g)
Servings Per Container 15
Amount Per Serving
Calories
Total Fat 10g
Sodium 25mg
Total
Carbohydrate 25g
100
5. Calculate your percent error for this experiment. (2 pts)
% DV
0%
1%
8%
Sugars 18g
6. List 4 possible errors that took place in the experiment that might contribute to your percent error. (4 pts)
7. In addition to calorimetry, food chemists can also conduct other chemical analysis to determine the composition of a food item.
a. Briefly, what is the purpose of a Kjeldahl analysis?
(2 pts)
b. Briefly, what is the purpose of a hexane extraction. (2 pts)
PART 2: Macromolecule Composition of a Marshmallow
DATA: (6 pts)
Observations:
What do your observations
tell you about the
composition of a
marshmallow:
Results of Marshmallow solution with
Benedict’s solution:
Results of Marshmallow solution with
Iodine solution:
Results of Marshmallow solution with
Biuret’s solution:
ADDITIONAL QUESTIONS: (14 pts) Please answer the questions on the blank on the left. Each
question is worth 2 pts.
_______________ _______________
1. In the Benedict’s test, an aldehyde group gets oxidized to a carboxylic acid.
Meanwhile, Cu2+ gets reduced to ____ in the form of _____, which is a reddish
precipitate.
_______________________________
2. The main ingredient in marshmallows, not surprisingly, is corn syrup. Corn syrup
is primarily what sugar?
________________________________
3. Related to corn syrup, the most common sweetener used in soft drinks has the
acronym, HFCS 55. What does HFCS stand for?? What does the “55” stand for?
________________________________
________________________________
4. A strict vegetarian would probably exclude marshmallows from their diet. What
is the specific ingredient in a marshmallow that is extracted from the bones,
connective tissues, organs, and some intestines of animals. This particular
ingredient adds to a marshmallows spongy texture.
_____ ______ ________________ 5. Corn starch is made up of approximately ____ % amylose and _____%
amylopectin. The I2 in the Lugol’s starch test interacts with the ____ portion.
6. Circle which of the following would NOT contain corn starch? You can circle more than one.
Chicken gravy
Pizza
________________________________
Mayonaise
Honey
Powdered sugar
7. In the Biuret’s test, Cu2+ form a coordinate complex with nitrogen atoms involved
in the ____ bonds of the proteins creating a lovely shade of violet.
PART 3: % Air in a Marshmallow
1. Calculate the volume of a puffed marshmallow (2 pts):
2. Measure the volume of a de-aired marshmallow (2 pts):
3. Calculate the % Air in a marshmallow (2 pts):
Exp #2: % Sugar in Beverages (27 pts total)
DATA: (10 pts)
Substance:
Mass:
Volume:
Density: (D=m/V)
0% Solution
5% Solution
10% Solution
15% Solution
20% Solution
Coke
Diet Coke
CALCULATIONS/ANALYSIS:
1. On the graph below, graph % sugar on the x-axis and density on the y-axis. Draw a best fit line. (4 pts)
Density of
Solution
(g/mL)
% Sugar in solution
2. Use your graph, to determine the % sugar in the coke and diet coke sample. NOTE: Diet coke and coke zero, of course, don’t
have any sugar in it. It’s percentage off of the graph, therefore, is equivalent to % sweetener. (4 pts)
% Sugar for Coke is _________________
% Sweetener for Diet Coke is _____________________
3. Let’s use freezing point depression data and the information above to determine the identity of the artificial sweetener in Diet
Coke.
a. An experiment was conducted where Diet Coke was frozen (Diet Coke-sicles! YUM!!!). Using the data and
formula below, calculate the molality ( m 
moles of solute
) of the Diet Coke. (2 pts)
kg of solvent
Freezing Point Depression Formula: Tf = Kfm
Molal Freezing Point Depression constant, Kf: 1.86oC/m
T (initial): 0.00000oC
T (final): -0.00339oC
** Yeah, I know. The temperature data is a little unrealistic! 
b. Using the molality above and the actual % by mass of sweetener in diet coke, calculate the Molar Mass of the artificial
sweetener. Remember, molar mass is mass per mole of a substance. (3 pts)
c. Based on your answer to B, what artificial sweetener is used in Diet Coke??? Circle your answer. (2 pts)
Saccharin, 183.89 g/mol
Acesulfame potassium (Ace-K), molar mass = 201.24 g/mol
Aspartame, molar mass = 294.30 g/mol
Sucralose, molar mass = 397.64 g/mol
4. In a nutshell, why are the diet soda’s so much less dense than regular coke??? (2 pts)
Station 3: Match that Label ( 16 pts Total)
TASK: Match the food labels on the next page with the most likely food item that they represent.
Good luck!!! And, Yum!!!
_____ 1. Starkist Albacore Tuna
_____ 2. Kraft Macaroni and Cheese
_____ 3. Nestle Chocolate Chips
_____ 4. Ruffles Reduced Fat Potato Chips
_____ 5. Newman’s Corn and Roasted Pepper Salsa
_____ 6. Sturkey’s Creamy Balsamic Vinaigrette Dressing
_____ 7. Dole Pineapple Chunks
_____ 8. Bush’s Great Northern Beans
Nutritional Facts for Station 3…..yummy!!!
A
B
C
D
E
F
G
Station 4: Marvelous Macromolecules( 15 pts Total)
TASK: Match the description on the left with the structure on the right!
_____ 1. Oleic Acid
_____ 2. Trans fatty acid
_____ 3. Omega-3 fatty
Acid
_____ 4. Triglyceride
_____ 5. Sucrose
_____ 6. Fructose
H
_____ 7. Lactose
_____ 8. Aspartame
_____ 9. Cholesterol
_____ 10. Amylose
_____ 11. Amylopectin
_____ 12. Cellulose
_____ 13. Tryptophan
_____ 14. Beta-carotene
_____ 15. Ascorbic
Acid
Station 6: Exploring Yeast Growth
TASK: Yeast, a very beneficial single-celled organism, has been used in the fermentation of foods for
thousands of years - from causing dough to rise to creating the unique tastes of beer and wine. A yeast
population is affected by a number of factors, the control of which is essential for optimal activity. In this
simulated experiment, we will consider the effect of four factors on yeast growth: pH, temperature, nutrient
concentration and nutrient type. The yeast feeds on sugars and since one of the by-products of the
fermentation process is carbon dioxide, the reaction will be monitored by capturing the carbon dioxide in a
balloon and measuring its volume.
Exp 1: TEMPERATURE
5 g of sucrose, 4 g of rapid rise yeast, and 80 mL of tap water were added to each flask. A balloon was
placed over the neck of each Erlenmeyer. Each flask was maintained at a different temperature:
Exp 2: SUGAR CONCENTRATION
4 g of rapid rise yeast and 80 mL of tap water were added to each flask. The temperature was maintained at
40oC. In each flask, a different amount of sucrose was added.
Exp 3: pH
5 g of sucrose, 4 g of rapid rise yeast and 80 mL of tap water were added to each flask. The temperature was
maintained at 40oC. In each flask varying amounts of vinegar and ammonia were added to change the pH.
Exp 4: NUTRIENT TYPE
4 g of rapid rise yeast and 80 mL of tap water were added to each flask. The temperature was maintained at
40oC. In each flask, 5 g of different sugars were added.
Station 5: General Questions ( pts total)
TASK: Please answer the following questions in the space provided on the left.
_____ 1.
_____ 2.
________3.
_____ 4.
_______ 5.
_______
_______
_____ 6.
_____ 7.
_____ 8.
_____ 9.
10.
.
1. Which of the following is not an example of
a dietary fiber?
a. cellulose
b. pectin
c. lignin
d. glycogen
2. Which substance below is a common
thickening agent in jam making.
a. pectin
c. corn starch
b. lethicin
d. gelatin
3. Consider the food label from a Crispy Ranch
snack wrap from McDonalds.
Nutrition Facts
Serving Size 4.1 oz (115g)
Servings Per Container 1
Amount Per Serving
Calories
???
Calories from Fat
Total Fat 16g
Saturated Fat 4.5g
Trans Fat 1g
Cholesterol 30mg
Sodium 780mg
Total
Carbohydrate 32g
Dietary Fiber 2g
Sugars 2g
Proteins 14g
Vitamin A 2%
Calcium 10%
???
% DV
25%
24%
10%
32%
11%
6%
Vitamin C 2%
Iron 10%
Calculate the total Calories. Assuming
proteins produce 9 Cal/gram and Proteins
and Carbohydrates produce 4 Cal/gram.
Write the answer on the blank.
4. A richly browned roast or steak with dark
grill marks tastes delicious due to the
chemical process known as browning.
Which description below would optimize the
browning process (Maillard reaction)?
a. Coat the meat with an oil.
b. Coat the meat with corn syrup and beef
stock.
c. Marinate the meat in pineapple juice.
d. Coat the meat with sugar and beef
stock.
5. What are the THREE critical ingredients
needed to make mayonnaise? Write them on
the three blanks to the left.
6. Which of the following amino acids would
be considered NONPOLAR?
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a
b.
.
c
d.
7. What is the major
a. milk clabber
b. rennin
.
protein in milk?
c. casein
d. Beta-lactoglobulin
8. Which of the following represents the
ZWITTERION form of the amino acid,
Alanine.
a. H2N—CH—COOI
CH3
c. H3N+--CH—COOH
I
CH3
b. H2N—CH—COOH
c. H3N+--CH—COO-
I
CH3
I
CH3
9. Which statement below is FALSE about
soluble and insoluble fiber.
a. Both insoluble and soluble fiber is
not digestible by humans.
b. Fruit, such as apples and oranges, are a
good source of soluble fiber whereas
vegetables are a good source of insoluble
fiber.
c. Soluble fiber has been found to reduce
LDL cholesterol (the bad cholesterol).
d. Insoluble fiber helps prevent constipation
and colon cancer.
e. There are no false statements.
10. Draw a peptide bond between a phenylalanine molecule (a) and a glycine molecule (b). Label the peptide bond. Draw
answer to the left in the designated box.
(a)
(b)
11.
_____ 12.
_____ 13.
_____ 14.
_____ 15.
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Why is it that fresh pineapple should not be used when making jello but is very commonly used as a marinade for meats like beef
or chicken?
How would your answer to (a) be different or the same if you used pineapple from a can.
What is name of the “active ingredient” in pineapple that creates the situations above.
Let’s say you are baking homemade blueberry muffins and they keep coming out really chewy and dense. Which of the following
choices could explain what you are doing wrong with your bread recipe.
a.
b.
c.
d.
You are mixing too much.
You mixed too little.
You are using a flour with too low of a percentage of glutin.
The blueberries contain an enzyme which interferes with glutin formation.
Glutin is a special protein essential in the baking process. Which of the following statements is FALSE about glutin.
a. The glutin organizes itself into long flexible strands or sheets in kneaded bread.
b. Glutin is made up of two different proteins, glutenin for elasticity and gliadin for
softness
c. Due to glutin’s nonpolar character, it repels moisture.
d. Wheat bread would have a higher glutin content than white bread.
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11. Many food additives have to undergo strict
regulations and analysis before they are
given GRAS status. What does GRAS
stand for???
12. Which statement is FALSE about partially
hydrogenated oils. Partially hydrogenated
oils…..
a. are used to extend the shelf life of
processed foods.
b. have a cis-unsaturated structure.
c. are more dense and have higher melting
points that the original veggie oil they
came from.
d. are linked to heart disease in that they
increase LDL and decrease HDL.
e. are produced by heating natural oils in the
presence of hydrogen gas and a metal
catalyst.
13. Probiotics or friendly bacteria are the newest craxe in the yogurt industry. These bacteria strains if consume for 2 weeks or
more are thought to have many positive health effects such as boosting the immune system, reduction of cholesterol and blood
pressure, improved regularity, etc. From all of the commercials on TV,
14.
15.
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