Presentation on theme: "Food and Nutrition Fats Test FOSS food and Nutrition, TESLA Science Notebooks."— Presentation transcript:
Food and Nutrition Fats Test FOSS food and Nutrition, TESLA Science Notebooks
BIG IDEA: Foods contain specific materials such as fats, proteins, sugars, and acid that work together to create healthy or unhealthy eating choices.
Engaging Scenario The nutritionist for the Lewiston School District is in charge of planning the lunch menu. She has a very difficult job because she is required by law to make lunches as healthy as possible, but she still needs to have students enjoy what they are eating. Whenever she chooses to update the menu she conducts tests on many different types of food to determine the type of nutrients they contain. There are so many different types of food available that she is asking for our help in determining which of our favorite foods contain the most fat. She needs us to keep accurate records and send her our results in two weeks. What do we need to investigate? What is the problem that needs to be solved?
Focus Question: How can we …test foods to determine the amount of fat that they contain? “Discuss with your group what we need to investigate and record it as the FOCUS QUESTION. This is the problem we are going to investigate and solve.”
Background Knowledge: Why do we eat food? For energy to move, to think, and to run the systems that keep us alive. Where does food come from? Plants and Animals What is food made of? Food is made of 6 groups of chemicals called nutrients: protein, carbohydrates, fat, vitamins, minerals, and water. Nutrients provide energy and building blocks to keep us alive. In this investigation we will be looking at one kind of nutrient: fat
Word Wall Nutrient: a chemical in food that helps keep organisms alive and active. Fat: a group of nutrients that provide energy and building blocks for the development of some body systems.
Materials from the District Nutritionist The districts nutritionist has sent us a list of foods that are commonly used in the lunch menu. Since she is so busy, she would like us to help her determine which of the foods are high in fat and which foods are low in fat. Our work will help her plan healthy lunches for students. Peanut Butter Cracker Hot Dog Bread Catsup Doughnut Mayonnaise Margarine Cookie Jelly Mustard Walnut Potato Chip Cheese Banana Apple
Peanut Butter Cracker Hot Dog Bread Catsup Doughnut Mayonnaise Margarine Cookie Jelly Mustard Walnut Potato Chip Cheese Banana Apple Create a list that compares the foods that you believe to be high in fat with foods that you believe to be low in fat in your science notebooks. What rational did you use to determine where you would place the foods on your list? Foods that Are High in FatFoods that Are Low in Fat
Prediction: I would like you to record a prediction in your science notebook. Using the foods from our list, discuss with your group which 2 foods will contain the most and least amount of fat. Be ready to share your ideas with the class.. EXAMPLE Prediction: I predict that _________________________ will contain the least amount of fat, because… I predict that ______________________ will contain the most fat, because…
Background Knowledge: Yesterday we made a chart that compares the amount of fat in the foods we eat. We did not have a lot of evidence to base our comparisons so we were basically just making predictions. Today we will begin testing some of the foods that we have collected and comparing the amount of fats in each. The district nutritionist is required by law to provide healthy menu items. She cannot serve a meal and tell people that she thinks it is a healthy meal. She needs to be able to provide evidence that the meal is healthy and meets the dietary guidelines she is required to follow.
Background Knowledge: “What do you think will happen if I place a greasy piece of food on this piece of brown paper?” --- Greasy foods leave a grease spot on paper “Would you consider this food to be high in fat?” --- To a chemist fats are chemicals called lipids, but to the district nutritionist, fats are oil and greases. “Could we compare the fat content of several foods using a brown paper test?” --- Discuss ideas with your group… What do you need to consider to set-up an investigation and produce fair and accurate results?
A Brown Paper Fat Test: In order for the results of this investigation to be fair and accurate, the variables in the experiment must be controlled. What are we going to change?What are we going to keep the same? The type of food we test The amount of food we use Where we place the food on the paper The time we allow for the grease spot to spread The type of paper we use for each food sample Place the samples in the same location, so all are affected by the same temperature and same light conditions.
A Brown Paper Fat Test: Procedures Steps for Controlling our Variables: 1.Make a 13cm brown paper square for each food item you are testing and one for a gram cube. 2.Use the base of a plastic cup and a permanent marker to draw a circle in the middle of each piece of brown paper. 3.Use a balance to weigh and distribute equal amounts of food (Make sure your balance is zeroed with two cups before you weigh anything) 4.Place a piece of brown paper on each side of the balance. Place a 1-gram cube in the center of the circle on one side of the balance. 5.Place a food item in the circle on the other side of the balance until balance is achieved. 1–gram on each side. 6.Spread the food sample so it covers the entire circle. If the sample is hard, smash the sample with a spoon until it is a dust or mush. Place a sheet of acetate over the food sample so the food does not stick to the spoon. 7.Label each of your samples 8.Tape your samples to a tray or large piece of cardboard lined with wax paper
Our Comparison Test On this tray I am going to set-up a comparison test using 1-gram of pure fat… Oil drops of oil is equal to one gram. Why would a sample of pure fat on a piece of paper make a good comparison test? --- Pure fat is our control or known comparison item. None of the items can contain more fat than pure fat. Some foods are naturally wet and contain more liquid than others. These foods will produce wet spots on the paper. How will we know if the spot is a result of fat or moisture? --- If we wait a couple of days the water/moisture will evaporate; fat will not.
Analyzing the Fat Test Today we are going to take a close look at the results of our fat test to see if we can help the nutritionist determine which foods contain more fats. Is there evidence that any of the food samples contain fat? --- Wet looking grease spots are evidence of fat. Do any of the foods appear to have more fat than others?
Analyzing the Fat Test We are going to use transparent Centimeter Grids as a tool to help us quantify the size of each grease spot. 1.Lay the grid over the grease spot and hold securely in place. 2.Count all the squares that are at least half darkened by grease spots. 3.You can use an overhead marker to mark the squares you count. Food TestedSize of Grease Spot (cm 2 )
Comparing our Results We can use our results to rank the foods tested from highest evidence of fat to least evidence of fat. If more than one group tested the same food item, we can use an average(mean). RankFood Tested Size of Grease Spot (cm 2 ) Etc. Quick Write: Which foods tested contained the greatest and least amount of fat? How do you know?
Math Extension: Calculating Fat %
Making Meaning: How can we tell how much fat is in a particular food? What can a grease spot tell us about the amount of fat in foods? How did we determine which foods contained the greatest amounts of fat?
Claims and Evidence: Based on what you have learned from your investigation of fats, you need to record some claims and evidence statements in your science notebook… Your evidence must be based on your data! I claim that… I know this because… Possible Example: I claim that foods that are high in fat produce larger grease spots than foods that contain less fat. I know this because…
11/8 November 2011 REFLECTION AND CONCLUSION What did you learn…? What really surprised you…? What new questions do you have…? What would you like to know more about…?