Gilmore, Marie Raster School

Objectives: 1. To test samples of food to find out if they contain fat. 2. To test fruit juices for vitamin C and compare the vitamin C content of the juices. 3. To calculate the number of calories per day that you eat. 4. To learn what information is given about food on a label. Materials: 1. unglazed paper (brown paper bags) food samples; margarine, butter, peanut butter, cheese, bacon, banana, salad dressing. 2. Methylene blue solution-dissolve 0.1g of methylene blue powder in 10ml ethanol 4 test tubes, dropper, fruit juices: orange, lemon, grapefruit, lime. 3. Calorie charts, food list from activity. 4. 10 different food labels, paper pencil. Strategy: 1. a. Hold a piece of unglazed paper up to a light. Notice whether or not light passes through the paper. b. Rub some fat or oil on the paper. Hold the paper up to a light. Notice any change in the paper. c. This smear test is the test for fats. Test samples of margarine, butter, peanut butter, cheese, bacon, banana, and salad dressing to see if these foods contain fats or oils. Record your observations. d. Try other substances that are suspected not to contain fats. 2. a. Add 10ml of methylene blue solution to a test tube. b. Use a dropper and add a drop of fresh orange juice to the test tube. Gently swirl the test tube. c. Continue to add orange juice to the test tube one drop at a time. Swirl the test tube after every addition. Count the number of orange juice needed to change the color of the solution from blue to colorless. d. Record this number. e. Repeat steps 1-3 using lemon juice, grapefruit juice, and lime juice. f. Record the number of drops of each juice needed to turn the methylene blue solution colorless. 3. a. Use the calorie charts and the food list from activity. Calculate the number of calories per day that you eat. b. Use the calorie charts to write balanced meals for one day. 4. a. Collect the labels from 10 of your favorite processed foods. b. Fill in the blanks in your data table with the information to each food.
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