Experimental problem with coaches notes A new processing plant opened with a complete line of sports drinks, juices and flavored waters. You are the quality control manager at the plant, and get a frantic phone call one afternoon. Someone has made a big mistake, putting all the drink base mixes into unlabeled containers! The products are: Clean Pro contains sugar, whey protein H2Oh! contains sugar, whey protein, starch Fruiti-O contains sugar Sweet T contains sugar, starch

Your job is to figure out how to label all the containers correctly! You have at your disposal all the needed equipment and reagents for the Biuret, Benedict’s, and Iodine tests. Each test kit has instructions. You are free to use as many or as few tests as needed to find the right labels for the drinks. There are central stations where you will find items for the following tests. All solutions are found at each bench station. Please label all glassware with sample identifier and your initials. Please wear protective eyewear and aprons. DO NOT TASTE ANY SAMPLES.

Biuret Test Materials: 4 test tubes pipettes Unknown drink bases Biuret reagent ****must wear glasses/goggles, apron and gloves to handle! Method: 1. Go to a central station and obtain test tubes. Return to bench. a. Insert tubes into marked racks 2. Pipette 20 drops of each sample into test tubes with plastic pipettes. 3. From the Biuret bottle, add 5 drops of Biuret solution to each labeled tube with plastic pipette. Gently swirl contents of tube. 4. Wait 10 minutes. 5. Observe and record results in the table. 6. Clean up area by emptying liquids into container and placing all tubes into glass disposal box and wipe down all surfaces. Rack should be free for next users.

Results of Biuret Test Test Tube/Sample Unknown 1 Unknown 2 Unknown 3 Unknown 4

Color After Addition of Biuret Solution to Sample

Positive or Negative Result

Benedicts’s Test Materials: 4 test tubes Styrofoam cup Unknown drink mix bases Benedicts’s Solution Hot water pipettes Method: 1. Go to a central station and obtain test tubes. Label tubes 1-4 with marker. Return to bench. 2. Insert tubes into marked racks. 3. Add 20 drops of each unknown solution to corresponding test tube. 4. Add 5 drops Benedict’s solution to each unknown. 5. From hot water dispenser, fill Styrofoam cup ¼ full of hot water and carry to bench space. 6. At bench, place tubes in cup of hot water for 5 minutes. 7. Place tubes into rack for observation. 8. Observe and record results in the following table. a. Green, yellow, orange or red are positive reactions. 9. Place waste in designated container and dispose of glassware in glass box. 10. Pour water down sink.

Results of Benedict’s Test Test Tube/Sample Unknown 1 Unknown 2 Unknown 3 Unknown 4

Color of Solution

Positive or Negative Result

Iodine Test Materials: 4 test tubes pipettes Unknown drink bases Iodine Solution Method: 1. Obtain test tubes at central station. 2. Return to bench. Place test tubes in rack at your bench area. 3. With plastic pipettes, pipette 40 drops each unknown solution into corresponding test tubes. 4. Add 1drop iodine to test tube for each unknown. Do not shake or swirl. 5. Observe and record results in the following table under step 1. a. Blue or blue/black color is positive result 6. Place waste in designated container and dispose of glassware in glass box.

Results of Iodine Test Test Tube/Sample Unknown 1 Unknown 2 Unknown 3 Unknown 4

Color of Solution

Positive or Negative Result

Results Table After tests, please record results in individual test sheets, then complete the following table and questions, then tell us which label is correct:

Sample #

Biuret

Benedict’s

Pos (+), Neg (-)

-/+

Iodine

Correct label for beverage

-/ +

U1 U2 U3 U4 1. What component did the Biuret test measure? ___________________________5 pts

2. What metal salt is used in the Biuret reagent to form a complex? ____________5 pts 3. What component does the Benedict’s Test measure?______________________5 pts 4. What reason can you give for sample U4 reaction to the Benedict’s reagent?

_______________________________________________________________8 pts 5. What sugar could have been in sample U2?______________________________5 pts 6. What metal salt is used in the Benedict’s test?___________________________5 pts 7. What component did the Iodine Test measure?__________________________5 pts 8. How many experiments did you run?_________________________________5 pts Why? ___________________________________________________________10 pts 9. What is the density of the cupcake/muffin on the table? _________________________10 pts 10. What is the viscosity of the batter on the table? ______________________________10 pts

Formulation of mixes: All the following can easily be made with ingredients found in the grocery store. These were prepared using 1-2% of each of the items. □ Protein o Whey protein can be found in the vitamin or supplement section or at a GNC or similar store. o Egg white (liquid or powdered) from fresh eggs or dried powder. o Gluten (sometimes found in the baking section with organic items) □ Carbohydrate o Corn Syrup (such as Karo brand) - fructose o Pancake Syrup- fructose o Table sugar – sucrose (won’t react with Benedict’s) □ Starch o Corn Starch – heat to boiling to dissolve starch, then cool before adding other ingredients. o Potato flakes (Instant mashed potatoes) –high in starch, also may get slight reaction with protein test. o □ Mixtures o Flours –cake flour and bread flour are different than regular flour o Rice – make rice and soak in water, then strain. o Bananas – ripe bananas have more sugar, less starch than green bananas, which may contain no sugar.

Clean Pro contains sugar (sucrose), whey protein H2Oh! contains sugar (corn syrup), whey protein, starch Fruiti-O contains sugar (pancake syrup) Sweet T contains sugar (pancake syrup), starch

Standard Viscotester Curve for 25 ml of fluid 800 y = 0.1002x - 3.0354 R² = 0.9972

700 600

Time (sec)

500 400 300 200 100 0 0

1000

2000

3000

4000

5000

Viscosity of fluid (cp)

6000

7000

8000

Sample #

U1 U2 U3 U4

Biuret

Benedict’s

Iodine

Pos (+), Neg (-) Pos (+)

-/+ Pos (+)

Pos (+)

Pos (+)

Neg (-)

Neg (-)

Neg (-)

Pos (+)

Pos (+)

Neg (-)

Neg (-)

Neg (-)

Correct label for beverage

-/ +

H2Oh! Clean Pro Sweet T Fruiti-O

1. What component did the Biuret test measure? __Protein____5 pts

2. What metal salt is used in the Biuret reagent to form a complex? ___Copper___5 pts 3. What component does the Benedict’s Test measure?____Reducing Sugar_____5 pts 4. What reason can you give for sample U4 reaction to the Benedict’s reagent?

The sugar is not a reducing sugar______________________________________8 pts 5. What sugar could have been in sample U2?___Succrose__________________5 pts 6. What metal salt is used in the Benedict’s test?__Copper__________________5 pts 7. What component did the Iodine Test measure?__Starch_________________5 pts 8. How many experiments did you run?______6________________________5 pts Why? Once you know which ones contain protein and starch, you can deduce the rest 10 pts 9. What is the density of the cupcake/muffin on the table? _________________________10 pts 10. What is the viscosity of the batter on the table? ______________________________10 pts