The Journey of North Carolina Sweetpotatoes After Harvest

Essential Files/Links

• From Farm to School – Crops of North Carolina: Digging for Sweetpotatoes (book)
• Health of Sweetpotato Article
• Nutrition Facts Label
• Note Taking Sheet
• North Carolina Sweetpotatoes Ag Mag
• Link to find growers: https://ncsweetpotato.com/sweet-potato-industry/growers/
• https://www.youtube.com/watch?v=PTxL4vrem5o
• https://www.ncfb.org/
• https://www.ces.ncsu.edu/directory/
• https://www.youtube.com/watch?v=g7u6pIfUVy4
• Video: MVI_8085
• Video: MVI_8124

Vocabulary

Agriculture: the science or practice of farming, including cultivation of the soil for the growing of crops and raising animals to provide food, wool, and other products.

Commodity: a raw material or an agricultural product that can be bought and sold such as a sweetpotato.

Consumer: a person who purchases goods and services for personal use.

Curing: preserving of food or animal hide by various methods such as salting, drying, or smoking.

Energy: the process or ability to do work.

Humidistat: (sometimes called a hygrostat) a small measurement device that helps monitor and maintain the relative humidity in the air connected to a humidifier to release moisture in the air to maintain relative humidity.

Kinetic energy: energy an object possesses by virtue of its motion or the calculation of the object’s mass and velocity.

Potential energy: stored energy or energy provided by work that has been done or by its position. Producer: a person, company, or country that makes, grows, or supplies goods or commodities for sale. Storage root: roots that are specifically modified for storage of starch, water, and nutrients such as carrots, beets, and sweetpotatoes. They grow underground as protection from plant-eating animals.

Thermostat: a small measurement tool that measures temperature. It automatically regulates temperature or activates a device when the temperature reaches a certain degree.

Tuber: a thickened underground part of a stem or rhizome, e.g. in the potato, serving as a food reserve and bearing buds from which new plants will grow.

NC Ag Facts

• North Carolina grows nearly 60% of all United States sweetpotatoes (more than any other state in the United States).¹
• The sweetpotato is North Caolina’s state vegetable.¹ The single-word term helps differentiate the sweetpotato from the white or Irish potato, which is a tuber, not a root, and possess a different nutrient profile. Sweetpotato – Ipomoea batatas, a storage root, is part of the morning glory family. ⁷
• North Carolina sweetpotatoes are available every month of the year.³
• Most sweetpotatoes are grown in the piedmont and coastal plain regions of North Carolina because of the well-drained, sandy soil.³
• There are hundreds of varieties of sweetpotatoes and many are grown across North Carolina. Some you may see most often in grocery stores include the Japanese sweetpotato, the White sweetpotato, and the orange flesh Covington sweetpotato.³
• In 2017, nearly 89,500 acres of sweetpotatoes were harvested; 30,000 more acres than California, Louisiana, and Mississippi combined.⁴
• North Carolina has produced more than one billion pounds of sweetpotatoes for the last seven years; this is the only state to exceed one billion pounds.⁴
• In dollars, North Carolina had the largest increase in 2017 at just over $37 million.⁴

Background Knowledge

Did you know that sweetpotatoes are actually part of the morning glory family? It is a perennial (perennials regrow every spring); though it is cultivated as an annual (annuals live for one growing season, but often cannot be overwintered). The creeping stems of this amazing plant can grow up to 20 feet long and frequently send out roots at the nodes which, in favorable seasons, bear small potatoes.

There are three main types of leaves: round, shouldered, and lobed or split. The color of the stems and leaves varies from dark green to light purple. No flowers are produced except in southern latitudes.⁵

The skin color of a sweetpotato can range from white to yellow, red, purple, or brown. The flesh also ranges in color from white to yellow, orange, or orange-red.⁶

So, is it a yam, a sweetpotato, or are they the same thing? The truth: yams and sweetpotatoes are not the same thing at all. There are thousands of sweetpotato varieties. Sweetpotato varieties are classified as either ‘firm’ or ‘soft’ – firm varieties were produced before soft varieties. When the soft varieties were grown there was a need to differentiate between the two (firm or soft). Africans actually named the ‘soft’ sweetpotatoes ‘yams’ because they resembled the yams in Africa. Their native word was ‘nyami’ and if the n & i are removed the term ‘yam’ remains. Despite this identification, this is not true. In fact, while the ‘soft’ varieties look like yams, they are not yams at all; it is just a variety of sweetpotato.

Yams are often imported from the Caribbean; they are rough and scaly—very different from our smooth, orange flesh variety sold in the United States. In the United States, people often use the word sweetpotatoes and yams interchangeably; however, this is not correct and often adds confusion for the consumer. When a consumer goes to the store and purchases ‘yams,’ they are more than likely purchasing a variety of sweetpotato. Today, the U.S. Department of Agriculture requires labels with the term ‘yam’ to be accompanied by the term ‘sweetpotato.’⁶

According to the North Carolina Sweetpotato Commission, North Carolina has ranked number one in sweetpotato production in the United States since 1971 (2018). North Carolina’s hot, moist climate and rich, fertile soil are ideal for cultivating sweetpotatoes. Sweetpotato production in North Carolina averages nearly 60% of the U.S. supply.³

Climate

Sweetpotatoes can be grown where there is a long frost-free period with warm temperatures in the growing season.³ Most cultivars require a minimum frost-free period of 90-120 days, with a minimum average daily temperature of 77 degrees Fahrenheit. Sweetpotatoes also require an inch of water per week uniformly distributed throughout the growing season for highest yields.³

Uses for Sweetpotatoes

Sweetpotatoes have many uses. They can be prepared in a number of dishes, canned, pureed, preserved and dehydrated. For drying, clean washed potatoes are placed in a suitable basket and immersed in boiling water for a short time; when taken out of the basket, they are cut into thin slices and spread over mats and exposed to the sun for two or three days. In order to make a superior quality, the skin of the potato is peeled off before slicing. Instances were reported wherein the dried product was successfully ground into flour.⁵ In North Carolina a company named Glean produces a sweetpotato flour. Sweetpotatoes can also be used as food stock for animals. They have been successfully fed to hogs, cattle, horses and poultry.

How to Play KAHOOT!

Let’s play KAHOOT!!!! If you do not have an account set up, please follow the link here: https://create.kahoot.it/register to register. Once you have registered you may begin creating an interactive game for your students to learn and enjoy. Log into KAHOOT and simply click discussion, survey, multiple choice, or jumble to start making a quiz. Then you will add your questions using the NC Ag Facts and Background Knowledge sections of the lesson plan. Once you have created your Kahoot game, launch the game so players can join. A unique game pin will be provided and players will enter this pin to join. Remember this link: https://kahoot.com/ to be put in the browser of your device (computer, phone, iPad, tablet, etc.) to join the game. Kahoot can be used in many ways to ignite learning in your classroom.

Activity 2: Processing Sweetpotatoes

Objectives Covered: 7.P.2.1, 7.P.2.2, 7.P.2.4

1. Review the vocabulary terms, energy, potential energy, and kinetic energy with the students and ask for examples. Energy is the process or ability to do work. For any machine to work it has to have energy. Objects can have stored energy, also called potential energy (when work has been done). Kinetic energy is the energy that an object possesses by virtue of its motion or the calculation of the object’s mass and velocity.
2. Watch the four minute YouTube video Professor Dave. Have students discuss what they learned from the video and specifically how energy would be involved in processing sweetpotatoes.
3. Next, place students into groups of 4-5 and have them watch, discuss, and take notes on the following three videos.
4. Show the first video regarding a Sweetpotatoes Packing Facility (MVI_8085)
   • Video Summary: This video shows washing and cleaning of sweetpotatoes that are sent through a process to sort them based on size. Give students 5 minutes to discuss examples of energy seen in the processing of sweetpotatoes and use the Note Taking Sheet to record this information (see Essential Files).
5. Show the second video, Sweetpotato Production
   • Video Summary: This video demonstrates the processes and machines used in processing sweetpotatoes. Have students take note of the way in which the machines work. This process demonstrates how sweetpotatoes are plowed for harvest, sorted, washed, and cut up for making flour. Give students 5 minutes to discuss examples of energy seen in the processing of sweetpotatoes and use the Note Taking Sheet (see Essential Files) to record this information.
6. Show the last video about Cleaning and Sorting Sweetpotatoes (MVI_8124)
   • Video Summary: This video takes place at a packing facility where sweetpotatoes are taken directly from the field to the packing facility. The sweetpotatoes are carried in large wooden crates, lifted with machinery to be dumped into water, pulled through on a conveyor belt to be cleaned, sorted and more. All of this takes place before reaching the grocery stores, farmers markets, and our tables. Allow students 5 minutes to discuss examples of energy seen in the processing of sweetpotato and use the Note Taking Sheet to record this information (see Essential Files).
   • Extension: An alternative to note taking via pen/paper is to create a Padlet account (free) and have students post their comments/summaries about the video to share with the whole class. See website: padlet.com
7. Tell the students, “Now that you have seen several examples of how machines and energy are used to process sweetpotatoes, it is time to share out your ideas, what is your take away?”
8. Have students demonstrate different examples of kinetic and potential energy. Have them draw an example seen on the videos of kinetic energy and explain their reasoning. Student examples may include machines used in the processing plant, including equipment used to transport the sweetpotatoes for packing and shipping (i.e. forklift, etc).
9. Extension Activities:
   • Allow students to create kinetic and potential energy projects using random materials found in the classroom, at home, etc. Examples of machines or equipment that push and pull on each other to work.
   • OR: Have students write a story based on managing a sweetpotato packing plant, which potato would you select for the consumer and why? Discuss how the role of ethics impacts sweetpotato packing and management of sales. Think about what the consumer (people who eat the sweetpotatoes) likes to eat and how they want it to look. What’s the farmer’s role to ensure he/she produces a good quality product that consumers will buy and enjoy? Remember to reiterate the role of a producer and a consumer. Producer: a person, a company, or country that makes, grows, or supplies goods or commodities for sale. Consumer: a person who purchases goods and services for personal use.

Activity 3: Farm to Plate!

Objectives covered: 6.P.2.2, 6.P.3.1, 8.P.1.3, 8.L.5.2, WHST.6-8.2, WHST.6-8.7

Most every school has a microwave in the teachers’ lounge, or in the school cafeteria. Before the lesson, decide what method to use in regards to cooking or pre-cooking the potatoes.

1. Pass around a microwavable sweetpotato (it can be wrapped tightly in saran wrap).
2. Allow students to feel the potato (it will be hard, have no smell, etc.)
3. Discuss the nutritional value of a sweetpotato. Pass out the Nutrition Facts Label (see Essential Files) for students to view.
4. Next, use a microwave to cook one sweetpotato at a time. Minutes: 5 minutes 800 – 1000 watt microwave.
5. As the potato is cooking, have students take notes of what they see: moisture, humidity, steam, or change in size (i.e students should illustrate the transfer of heat energy).
6. Take out sweetpotato and allow it to cool.
7. Pass around microwaved sweetpotato, allow students to lightly press, smell, and feel the potato.
8. How has it changed and why? The sweetpotato is soft, you can see juices have formed and the skin has pulled away from the flesh of the potato. Document other observations students notice. Can they smell the sweetpotato, has the size of the sweetpotato changed?
9. Discuss with students the process that took place to cook the potato and caused the change.
10. Add butter, brown sugar, cinnamon, marshmallows mash up and allow each student to have a Have them read the nutrition facts label of each item they added to the sweetpotato before eating. Did it change the caloric intake of the sweetpotato? Did it enhance the sweetpotato taste?
11. Why do consumers eat sweetpotatoes? What are the benefits? Provide students with the informational text found in the Health of Sweetpotato Article (see Essential Files). This is an opportunity to show an emphasis on the relationship between respiration and digestion as energy is used during each process. Have them share what they learned from the article. Ask the following questions:
    1. What benefits do sweetpotatoes provide for professional athletes?
    2. If sweetpotatoes are considered to be calorie friendly, what does that mean?
    3. Can a sweetpotato potentially reduce you from getting sick? If so, how?
12. Next, place students in groups of 2 and have them make their own version of sweetpotato pie filling.

Group Activity: Oh, my Sweetpotato Pie!

Instructions:

1. Students will select a partner. Students will need measuring cups, 2 plastic bags, cooked sweetpotatoes, cinnamon, and a spatula.
2. Students will begin by digging out the inside of the sweetpotato and putting the inside of the sweetpotato in a measuring cup and then place into a plastic bag.
3. Students will pour ¼ cup sweetened, condensed milk into the plastic bag with sweetpotato filling. Add a teaspoon of cinnamon.
4. Students will then place the plastic bag inside the second plastic bag for extra support. Pass the bag back and forth, allowing each student to mash & mix the ingredients together. Students will notice that the solid and liquid begin to mix together and the color will begin to change slightly. When the solid and liquid have mixed well, it is ready to taste.
5. Have students take a spoonful of the mixture and put it on a cinnamon graham cracker to taste.