Test for Simple Sugar

Test for Simple Sugar.

Christa Hollister

October 21, 2009

Mrs. Nichols, Biology

Problem: What food products have sugar in them.

Hypothesis: I think that if I add Benedict’s solution to sugar-free pudding, an apple, a potato, and milk then the apple and milk will change color and then the sugar-free pudding and potato won’t change color.

Materials:

·  Sugar-Free Pudding

·  Apple

·  Potato

·  Milk

·  Benedict’s Solution

·  Graduated Cylinder

·  Dropper

·  Distilled Hot Water Bath

Procedures:

1.  Create a data table with columns labeled Food Substance, Sugar Prediction, Observations, and Results.

2.  Choose four food substances from those provided. Predict the presence of simple sugar in each food. Record your prediction.

3.  Prepare a hot water bath. (The teacher will pour hot water into your beaker when you are ready.)

4.  Label four test tubes. Obtain a graduated cylinder. Add 10 mL of a different food substance to each test tube. Then add 10 mL distilled water. Swirl gently to mix.

5.  Add 5 mL of Benedict’s solution to each tube. Use a clean stirring rod to mix the contents.

6.  Using test tube holders, warm the test tubes in the hot water bath for 2-3 min. Record your observations in your table.

7.  Analyze the following questions.

Data:

Type of Food. / Prediction. / Observe. / Results.
Sugar-Free Pudding. / No, glucose. / Turquoise color, cloudy, and little chunks. / No, glucose.
Apple. / Yes, glucose. / Darker blue, you can see through it. Has little apple floaty things in them. / Yes, glucose.
Potato. / No, glucose. / Darker blue then the rest, a bit cloudy. / No, glucose.
Milk. / Yes, glucose. / Light blue color, cloudy, and big chunks. Looks like a sky with clouds. / No, glucose.

Analyze:

A: Did any of the foods contain simple sugars? The apple contained a simple sugar called glucose.

B: Could a food labeled “sugar free” test positive using Benedict’s solution as an indicator? Explain. A “sugar free” product could test positive using the Benedict’s solution because it could use fake or man-made sugars.

Conclusion: My hypothesis was incorrect. All of the foods didn’t have sugar in them, but the apple. The apple changed from blue to orange at the top to green at the bottom. The apple is the only one that had any changes since putting it in the hot water bath. Our independent variables were the water and Benedict’s solution and our dependant variable was the food products and the color change. Some possible errors that might of occurred in our experiment would be the measuring of the liquids. Another error was that one of our test tubes and the mix went all over the table. If I did this lab again I would change the food products used, the amount of water, the size of our test tubes, and I would calculate the temperature of the hot bath. Overall this was a good educational lab.