The Quicker the Better? Food Processing (Grades 6-8)

Lesson Plan

Grade Level

6 - 8

Purpose

Students explore different levels of food processing and the ways in which processed foods affect the health of our diets by looking at examples of foods from the grocery store and by closely examining food labels. Grades 6-8

Estimated Time

2 - 3 hours

Materials Needed

Engage:

Cow to Milk Images

Activity 1: What is food processing?

The Quicker the Better? Food Processing PowerPoint slides
Levels of Food Processing handout
From Farm to Table activity sheet, 1 per student
One grocery bag containing 3–5 examples of processed foods that come from the same raw product. For example:
- Oats - regular rolled oats, instant oatmeal, oatmeal cookies
- Wheat - whole wheat flour, white flour, pasta, pancake mix, bread, frozen waffles
- Corn - frozen corn, canned corn, corn flour, corn tortillas, corn flakes cereal, sweets containing high fructose corn syrup
- Apples - fresh apples, apple juice, applesauce, dehydrated apples, apple desserts
- Chicken - frozen/fresh chicken, chicken broth/stock, chicken nuggets, canned chicken noodle soup, frozen chicken-based dinner
Food labels (including name of food, nutrition facts, and ingredients list), 2–3 per pair of students

Activity 2: Nutritional Value

Food labels (can use the same labels as above)
Internet access for student research
Calculators and scratch paper for each student

Activity 3: Activity Sheet Review

An Inconvenient Truth activity sheet

Vocabulary

food processing: the process of transforming raw agricultural products, like grains, vegetables, meat, or milk, into end products to be sold to consumers

Did You Know?

Fortification is a type of food processing. In the United States some commonly fortified foods are salt (with iodine), milk (with vitamin D), and grain products (with thiamin, niacin, riboflavin, iron, and folic acid).¹
Between 1966 and 1999 the amount of time that US adults spent cooking meals decreased by 25%.¹
The Native Americans of the Great Plains made a convenience food called pemmican that consisted of strips of dried buffalo meat mixed with fat and berries.¹

Background Agricultural Connections

Food processing is the action of transforming raw agricultural products, like grains, vegetables, meat, or milk, into end products ready to be sold. Most foods that we consume require some processing. Everything from chopping to mixing ingredients to cooking can be considered a part of food processing. A processed food has been changed physically or chemically after being harvested. The amount of processing varies from food to food, ranging from minimal to high.

Minimally processed foods are changed only a small amount between the farm and the consumer. These foods might be washed, peeled, sliced, juiced, frozen, dried, or pasteurized. They have few ingredients (often only one), which are all things that could be found in a home kitchen. Examples include skim milk, pre-washed and torn lettuce, frozen vegetables, and flour. A packaged pancake mix that includes only the dry ingredients and requires the consumer to add milk, eggs, and oil at home could also be considered a minimally processed food because all of its ingredients are minimally processed. Many foods in this category are ingredients that would be used to cook a meal at home.

Moderately processed foods are somewhat changed from the form in which they left the farm. In addition to being washed, peeled, and juiced, ingredients may be mixed, cooked, and have preservatives added. Moderately processed products often have several ingredients, and most, but probably not all, of those ingredients may be found in a home kitchen. Many of these foods still require some preparation before eating. Examples include a jar of spaghetti sauce, flavored yogurt, and bread. Another example could be a pancake mix that includes all the necessary ingredients, and you just add water to make the batter. This is different from the minimally processed pancake mix because the ingredient list will include some things that are highly processed, such as monocalcium phosphate, dextrose, and glucose solids.

Highly processed foods often have many ingredients and are mostly or fully prepared in the factory. Little or no preparation needs to be done before eating. Many snack foods like chips and candy are highly processed. Frozen pizzas and microwave dinners are also highly processed. These foods contain many ingredients not found in a home kitchen that add vitamins and minerals, enhance flavor and texture, and extend shelf life. Individual ingredients may be processed before being combined for further processing. Some ingredients commonly found in highly processed foods include high fructose corn syrup (sugar extracted from corn), polysorbate 65 (an emulsifier that keeps water and oils mixed), and sodium erythorbate (a food additive in processed meats that helps to retain color and improve flavor).

Foods are processed for many reasons. Some foods are more easily digested or safer to eat with some processing. For example, cooked potatoes are more nutritious and taste better than raw potatoes, and cooking meat and eggs kills harmful bacteria that can be carried on these foods when raw. Foods may also be processed so that they will store longer, taste better, or be more convenient to eat. However, processing that involves heating foods to very high temperatures or separating whole foods into their components can reduce nutritional value. Food processing can also be energy intensive and packaging can generate large amounts of garbage. There are both advantages and disadvantages to food processing.

Engage

Ask students if they think milk is a processed food. If needed, give students the definition of food processing. Display the first Cow to Milk image. Ask students, "Does milk go straight from the dairy farm to a grocery store?"
Ask students to use their prior knowledge to help you make a chronological list of what happens to milk from the time it leaves the dairy farm where it was produced until it arrives at the grocery store to be purchased. Use the second Cow to Milk image to help illustrate.
- At the dairy farm, the milk was cooled and stored in a tank until it was transported to a milk processing plant.
- At the milk processing plant it was pasteurized, separated into cream and milk, recombined into milk with 2% fat, and homogenized to prevent the cream from separating. The vitamins A and D were added to the milk. Finally, the milk was packaged in cartons or jugs.
- Last, the milk is transported again in a refrigerated truck to the grocery store. This entire process only takes a few days.
Ask students again if they think milk is a processed food. What about cheese, butter, or ice cream? Inform your students that they will be learning about food processing.

Explore and Explain