The Arizona STEM Acceleration Project

Kill the Dyes

Kill the Dyes

A 3rd grade STEM lesson

Author: Tonya Page

Date 1/11/24

Notes for teachers

• This lesson takes place inside and outside the classroom within a 60 minute period.
• Students may work in small groups or whole class.
• An emphasis on the target product of identifying and designing a meal plan with all natural ingredients.
• Facilitate conversation on personal experiences of effects of natural vs. artificial ingredients.
• Creative products should be encouraged.

​

List of Materials

• 7 clear cups or jars (8 oz)
• water
• food coloring (red, blue, yellow)
• Coca-Cola
• fruit punch
• coffee
• timer
• measuring cup, flask
• celery stalks
• clock, timer

Science Standards

3.L1U1.5 Develop and use models to explain that plants and animals (including humans) have internal and external structures that serve various functions that aid in growth, survival, behavior, and reproduction.

3.L1U1.6 Plan and carry out investigations to demonstrate ways plants and animals react to stimuli.

3.L2U1.7 Develop and use system models to describe the flow of energy from the Sun to and among living organisms.

​

​

Science and Engineering Practices:

​

• ask questions and define problems
• develop and use models
• plan and carry out investigations
• analyze and interpret data
• use mathematics and computational thinking
• construct explanations and design solutions
• engage in argument from evidence
• obtain, evaluate, and communicate information

​

• ​
• ​

Math Standards

3.MD.A.1a Tell and write time to the nearest minute and measure time intervals in minutes. Solve word problems involving addition and subtraction of time intervals in minutes

​

3.MD.A.2 Measure and estimate liquid volumes and masses of objects using metric units.

​

​

​

Standards for Mathematical Practices (MP)

​

• Make sense of problems and persevere in solving them.
• Reason abstractly and quantitatively.
• Construct viable arguments and critique the reasoning of others.
• Model with mathematics.
• Use appropriate tools strategically.
• Attend to precision.
• Look for and make use of structure.
• Look for and express regularity in repeated reasoning.

​

National Standards

Next Generation Science Standards (NGSS)

• 4-LS1-1: Construct an argument that plants and animals have internal and external structures that function to support survival, growth, behavior, and reproduction.
• Connection: Students observe how the celery's internal structure (xylem) transports water and dye, serving as a model for how organisms transport nutrients (or harmful substances) throughout their systems.
• 3-5-ETS1-2: Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
• Connection: Students design a dye-free meal plan, comparing ingredients and food choices to meet the criteria of being "dye-free" and healthy.

• ​
• ​

Common Core Mathematics (CCSS.MATH)

• 3.MD.A.2: Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l).
• Connection: The lesson requires measuring specific amounts of liquids (water, Coca-Cola, fruit punch) for the celery experiment using measuring cups or flasks.
• 3.MD.B.3: Draw a scaled picture graph and a scaled bar graph to represent a data set with several categories.
• Connection: Students create charts or graphs to record and compare their observations of the celery stalks over time (e.g., rate of dye absorption).

Common Core English Language Arts (CCSS.ELA)

• RI.3.7: Use information gained from illustrations (e.g., maps, photographs) and the words in a text to demonstrate understanding of the text (e.g., where, when, why, and how key events occur).
• Connection: Students analyze food labels and potentially research FDA regulations, using text and images to understand what ingredients are in their food.
• W.3.8: Recall information from experiences or gather information from print and digital sources; take brief notes on sources and sort evidence into provided categories.
• Connection: Students keep a journal of their observations during the experiment and use their findings to categorize foods as "safe" (dye-free) or "unsafe."

Objectives:

Today I will be able to identify natural vs artificial ingredients in food products.

Today I will be able to identify the harmful effects of food dyes, specifically red dye in living organisms and relate it to the effects of artificial ingredients in my food consumption.

Today I will estimate and measure using time and volume.

Today I will design a desirable dye free meal plan.

​

Agenda (60 minutes)

Pre-learning: What is natural vs artificial?

Effects of dyes

Hands on: Celery Stalk experiment

Reading food labels

Natural food dyes in nature

Identifying foods with and without dyes

Design a dye-free meal plan

​

Intro/Driving Question/Opening

​

​

What effects does adding artificial ingredients to our food have on our bodies?

How can I identify natural vs artificial ingredients in my food?

How can I design a desirable meal that is dye free?

Hands-on Activity Instructions

• Video: What is the difference between natural and artificial ingredients:
• What are food dyes?
• The Most Harmful Food Ingredient
• Hands on: Celery Stalk experiment
• Finding Volume
• Connection: Capillary Action
• Reading food labels
• Natural food dyes in nature
• Identifying foods with and without dyes
• Design a dye-free meal plan

Background Knowledge: What are Food Dyes?

Video: What is the difference between natural and artificial ingredients:

Food dyes are chemical substances that were developed to enhance the appearance of food by giving it artificial color.�People have added colorings to food for centuries, but the first artificial food colorings were created in 1856 from coal tar.Nowadays, food dyes are made from petroleum.

Over the years, hundreds of artificial food dyes have been developed, but a majority of them have since been found to be toxic. There are only a handful of artificial dyes that are still used in food.

Food manufacturers often prefer artificial food dyes over natural food colorings, such as beta carotene and beet extract, because they produce a more vibrant color.

However, there is quite a bit of controversy regarding the safety of artificial food dyes. All of the artificial dyes that are currently used in food have gone through testing for toxicity in animal studies.

Regulatory agencies, like the US Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA), have concluded that the dyes do not pose significant health risks.

Not everyone agrees with that conclusion. Interestingly, some food dyes are deemed safe in one country, but banned from human consumption in another, making it extremely confusing to assess their safety.

​

The Most Harmful Food Additive

There are nine synthetic dyes that the FDA currently approved for use in food:

Blue 1 (Brilliant Blue)

Blue 2 (Indigo Carmine)

Citrus Red 2

Green 3 (Fast Green FCF)

Orange B (No longer used in the U.S., but was never officially banned)

Red 3 (Erythrosine)

Red 40 (Allura Red)

Yellow 5 (Tartrazine)

Yellow 6 (Sunset Yellow)

Foods commonly contain a mixture of different colored dyes. For example, foods such as cereal, ice cream, candy, and toaster pastries contain all 6 of the most commonly used artificial food colors (Blue 1, Blue 2, Red 3, Red 40, Yellow 5, & Yellow 6).

​

Why do Food Manufacturers Color Foods with Artificial Dyes?

​

​

First, using artificial dyes to color foods gives the food no nutritional value and is used primarily for aesthetic purposes. Specifically, artificial dyes are added to foods to: Make the food look more appealing and attractive to consumers, especially to children. Food coloring masks are the absence of brightly colored natural ingredients, such as fruit.They are much cheaper, have a longer shelf-life, and are brighter than most natural food colorings.

What Exactly are Synthetic Dyes aka Coloring Added to Foods?

The FDA defines a color additive as “any substance that imparts color to a food, drug, cosmetic, or the human body.” This definition leaves out a significant tidbit: Food dyes are man-made, complex chemicals initially made from coal tar but now from petroleum. Petroleum is a crude oil product commonly used to make gasoline, diesel fuel, asphalt (the sticky black stuff that a driveway is paved with), and plastic. Sounds pretty tasty.

​

What Food Dyes are Currently Used in Food?

Celery Experiment

A plant’s stems are like a framework or skeleton. Most plants have a main stem that grows out of the ground. Thinner stems grow from the main stem.

​

The function of a plant’s stem is to transport water and nutrients from the roots to the leaves, flowers or fruits. Celery is a vegetable made up of long fibrous stalks or stems on which leaves grow.

A celery stalk tubes are perfect for us to investigate how water is transported in the stems of plants.

​

Underground, a celery plant roots absorb water. Then the water is transported around the plant along “tubes” in its stems.

​

The process is called transpiration and it’s essential for moving water to reach all parts of plants, even to the tops of the tallest trees.

​

The experiment with a stick of celery reveals that this happens through special tubes, called xylems, which take up the food colouring.

What to do:

• Start out by looking at and talking about the features of the celery. Cut the stalks off and look at a slice of the celery, can you see the tubes?
• Color in your observations and make hypothesis for each stalk on your notes.
• Cut 7 stalks of celery from the base.
• Half fill 4 cups with water. Be sure to measure the water and take note (optional worksheet: What happened to the water? Make prediction as to what will happen and add to notes. Add food dye to 3 of the cups (you can use red, yellow and blue). You will want to use more than just a few drops of food dye so the colour is quite vibrant.
• Leave one cup with no dye to compare with at the end. This will serve as your control group.
• Fill the remaining cups half way with Coca-Cola, Hawaiian Punch and coffee.
• Place a stalk of celery into each cup of water and mark the time. Make a guess about what you think will happen and color in the cups and celery on the observation sheet. Leave the cups with the celery for at least 3 hours (overnight is better, or 24 hours). Follow the steps of the notes sheet and fill in observations along the way.
• What happened to the celery? Color in the results on the observation sheet. Cut a slice from each stalk, can you see the tubes now?
• Measure the remaining water. How does it match your prediction?

You will need:

Finding Volume: How much liquid is absorbed?

Choose the appropriate ability level of notes for your students.

Video: What is Volume?

Video: Estimating Liquid Volume and Mass

• Make predictions. What do you think will happen?
• Measure the water before and after and compare it to your predictions.
• Use your chart to compare each liquid and make observations.
• What happened to the water?
• How much water is left?
• Is it the same for all the liquids?
• Did anything change on the control cup?
• Were you surprised by the results?

Notes for higher grades

Track the Dye Worksheet

Celery predictions for younger grades- journal

Celery observations

Connection: Capillary Action

The cut celery stalks take up colored water through their stem and the colored water moves from the stem to the leaves. Water travels up tiny tubes in the plant via the process of capillary action.

What this means for our bodies…

We can compare the effects of the capillary action happening in the celery to what is happening in our bodies when we consume the dyes. As you will see, the celery in the liquids with the red dye has appeared to age at a must faster and detrimental rate than the other liquids.

Capillary action is important for moving water around. It is the movement of water in and out of your cellular structure that deposits vitamins, nutrients, and vital blood plasma. Without this flow, your body's cells would not rehydrate and vital communication between your brain and body would slow.

Know What to Avoid: �Reading Nutrition Labels

Hyperactivity in children can present by:

• constant fidgeting
• an inability to concentrate
• being unable to sit still
• excessive movement
• an inability to wait their turn
• interrupting conversations
• little or no sense of danger

​

Red dye 40 is a synthetic food dye made from petroleum. Research has shown that it is linked to certain ADHD symptoms, such as hyperactivity, and may also cause other neurobehavioral effects in children.

People can check for red dye 40 on food labels if they wish to limit their intake. It is important to note that it may go by other names, including Allura Red AC, Red 40, Red 40 Lake, FD&C Red no. 40 Aluminium Lake, and FD&C Red no. 40.

​

Selecting Healthy Options

Replacing processed food and taking dyes out of your diet does not mean your tastebuds must suffer. Delicious substitutions with natural dye-free ingredients are readily available.

A Guide on What is Healthy

Hands on Challenge: Creating a Dye-Free Meal

Video: Building a Healthy meal

• Use this Plate template and all your our new knowledge to create a desirable dye-free meal.

1. Print out the plate template and draw and color your foods or use cut out pictures from magazines and/or printed off the internet to create a collage. You can easily find old cook books in thrift stores to repurpose.

​

2. Turn it into a virtual activity. Make a digital copy of the plate for each student on a google slide. Students can scour the internet for images of delicious dye-free foods to add to their meal. By using the cut and paste and snip it tools students can create a digital collage. This is a great way to imbed technology into your lesson.

• Bonus: Stay under five ingredients for each food.

Create an entire day’s dye-free menu for your family.

The Big List of Dye Free Snacks

Assessment

Math: Accurately find the volume of each liquid before and after the experiment, then the (difference) amount absorbed for each liquid. Create visual displays such as graphs to track the difference between each liquid. Does this match your predictions? What conclusions can you draw?

​

Science: Create a desirable, dye-free meal your family would eat. Create a plate for each meal of the day. Create a week long dye-free menu for your family.

​

Writing: Keep a food journal for a week. Challenge students to watch ingredients carefully and limit their intake of foods with dyes. How do you feel after one week? Go back to eating normally. Compare. How do you feel? Do you notice any differences?

​

Differentiation

• Narrow down the experiment groups from 7 groups to 3 ( or anywhere in between)

​

• Take notes and journal whole class

​

• Assessment: Assign different groups different meals (breakfast, lunch, dinner) and side dishes to come together for a full day’s dye-free food consumption.

Remediation

Extension/Enrichment

• Recreate the experiment with Carnation flowers and/ or hard boiled eggs. This is a cool art project!

​

• Engineer a board game that has players identify healthy ingredients and foods while avoiding dyes.

​

• Code robots (spheros) to make its way through a maze while avoiding the “dye pitfalls.”

​

• Learn More about FDA regulations in U.S. and other countries. (Next slide)

​

• Take it a step further and invite students to bring in a dye-free meal. Host a dye-free pot-luck with students (and families). Be mindful of the amount of ingredients and award students whose dishes have the least amount of ingredients.

Who is the FDA and what do they regulate?

The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food safety along with any other product that may be consumed.

​

Food laws aim to prevent problems that can cause foodborne illness and other harmful effects, such as the food import and export of adulterated products that may prove to be non-compliant with general food regulations in any context.