The Cranberry MATERIALS: THINGS YOU NEED A package of fresh cranberries (six cranberries for each student); a pin; a sharp knife, a ruler, white paper, a glass, water, 2 bowls. LABORATORY WORK 1. Pick out a good cranberry; examine and notice its color, shape (cherry or bell like or a combination?), size, texture (smooth, bumpy, wrinkled, form, soft, waxy?), and shininess. Describe your berry. 2. If any of the cranberries have stems, examine them; if not, find the spot where the stem was attached and notice the little pit in which it was set. 3. Examine the end opposite the stem end; this is the blossom end, or the end from which the petals of the flower fell. Notice the white or brownish white points around a little hole. How many points are there? Can you find a tiny spot in the center of the hole? Sample file 4. Roll your cranberry around in the palm of your hand. Is it heavier or lighter than you expected? What do you think that tells you about the inside of the berry? 5. Does the cranberry have a smell? Is it strong or subtle? Describe it.
6. Does the cranberry have a pinch-sound? You will have to pinch it quite hard to find out. 7. With a pin, pick up a little piece of skin. What color is the berry under the skin? Ask an adult to cut off (or supervise you while you cut off) a bit of skin about as large as your finger nail; scrape away the white pulp that sticks to it. Hold this to the light and notice the color. Take the piece of skin between the thumb and finger of each hand; pull it and see whether it is tough or brittle. Write your observations in the space below. 8. Fill a glass with water. Pick out another cranberry. Do you think your cranberry will sink or float when you put it in the water? Why? Once you have made your prediction, place the cranberry in the water. What was the result; was your prediction correct? Prediction: Sample file Result:
Cross Section ADULT ASSISTANCE REQUIRED 9. Ask an adult to cut a cross section of a cranberry, and notice the four large holes arranged like a cross and the tiny seeds in each of these holes. Notice the pink color in the center of the cross and the white of the pulp. 10. With a pin pick out the seeds from one compartment and lay them on a piece of white paper. a. How many seeds are there? b. Are they all the same size? c. How large is the largest? Vertical Section ADULT ASSISTANCE REQUIRED 11. Ask an adult to make a vertical section. Notice the large holes or hollows, growing wider toward the blossom end; the pulp at the stem end. Can you see where the stem fibers run through the thickened pulp? Sample file 12. Ask an adult to cut some slices down the cheek of the berry so that one of the four holes is opened, and you can see the seeds attached to the inside, that is, to the center of the berry. They form a little bunch almost exactly in the middle of the berry. Do you see it? (You may have to cut several berries before this is clear.) 13. Cut a thin slice from the cross-sectioned half. Hold it up to the light and examine carefully. Does it look hard and solid?
Now take one of the cut halves and pinch it quickly so that you hear the pinch-sound and see the juice squeeze out. This will help you to understand why hard, solid things have no pinch-sound. 14. Cut off as large a piece of the skin of one of the berries as you can get off whole. If there is any white pulp on it, scrape it off with a pin or knife. Then hold the skin up to the light and examine it. Where is most of the coloring in the cranberry? 15. Cut a small slice of a cranberry. Taste it, and then chew it up. Is it sweet? Tart? Bitter? 16. Look at a picture of the cranberry vine. Notice the blossoms. Describe one. When the bud first opens the petals hang down almost straight, they soon begin to curl up. Sample file Notice the point that hangs down under the blossom. This point is formed of the stamens and pistol folded together. The cranberry was originally called a crane berry because of its resemblance to the neck, head and beak of a crane. Look at the picture of the cranberry blossoms again. Look at the cranes below; do you see a resemblance? Vertical section of a cranberry blossom, magnified
17. After the petals fall off the berry is left hanging upon its crimson stem. The berry is then very small, and either green or purplish green, and has a collar of four little points opposite the stem. Did you find four points on the grown cranberry? For Further Study: The Cranberry Bounce When you tested your berry and found that it floats in water, you learned something very important about cranberries: they have small pockets of air inside that allow them to float. These air pockets also allow fresh, ripe cranberries to bounce! However, as the quality of the berry declines as a result of age or damage (bruising, poor storage conditions, etc.), the berry will no longer bounce. This was a very important discovery for cranberry growers. Can you guess why? Before cranberry growers can take their berries to the market, they have to sort them to make sure only the best, highest quality berries are packaged and sold. Sorting the berries by hand is a hard, tedious process. Most growers today use devices that tumble and bounce the berries. The freshest berries bounce along the conveyer, but the damaged, poor quality berries do not bounce and are left behind. Sample file You can conduct your own bounce test with the whole berries you have left in your bag. You may use the worksheet provided on the next page to record your results each time. Select 20 berries Make a prediction: how many of the 20 cranberries will bounce? Drop each berry from a height of 1 foot onto a hard surface As you go, sort the berries that bounce from those that do not into separate bowls. Examine the berries. How do the berries that bounced compare with those that did not? Store the berries in the refrigerator.* Repeat the experiment (with the same berries) every other day until you have completed the test 5 times. * a variation of this experiment would be to keep half of the berries` that bounce in the refrigerator, and half stored at room temperature in order to show the effect of storage techniques on berry quality.
Cranberry Bounce Lab Notes 1. Prediction: I believe of the 20 berries will bounce when dropped from a height of 1 foot onto a hard surface. 2. Create a bar graph that shows your results. Use a pencil, crayon or marker to shade in one rectangle for each berry that bounced or didn t bounce. Cranberry Bounce Results, Day Number of Cranberries 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Sample file Bounced Didn t Bounce
3. Was your prediction correct? Explain why or why not. 4. Examine the berries that bounced and those that did not. What do you notice about the berries that bounced compared to the cranberries that did not bounce? 5. Fractions and Percentages (optional): Calculate what fraction of your cranberry sample (the 20 cranberries you are using for this experiment) bounced and what fraction of the sample did not bounce. Example: if 3 cranberries out of 20 bounced, we would write this as: 3/20. To calculate the percentage, divide the top number of your fraction by the bottom number and multiply the answer by 100. This is the percentage. Sample file Example: 5/20 = 5 20 =.25 Multiply.25 by 100 and you get 25%. Fractions and Percentages, Day cranberries out of 20 bounced. Write this as a fraction: cranberries out of 20 did not bounce. Write this as a fraction: % of cranberries bounced % of cranberries did not bounce
6. Once you have completed 5 days of trials, compile your results in a line graph that shows how many cranberries bounced on each day. (Above each day make a dot for how many berries bounced that day. Then connect the dots.) Number 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Day 1 Line Graph: Cranberries That Bounced Sample file Day 3 Day 5 Day 7 Day 9 7. Look at your completed line graph. Did the number of cranberries that bounced increase or decrease over time? Why do you think that is?
CRANBERRY LAB STUDY GUIDE In the United States, the American Cranberry is primarily raised in the states of Massachusetts, New Jersey, Oregon, Washington and Wisconsin. Traditionally, cranberry growers make what they call cranberry bogs by digging ditches through a marshy place and then cover the spaces between the ditches with sand. In this sand the cranberry vines are planted where they grow and spread. The bogs are commonly covered with water during the winter, as a protection against frost. This has an additional advantage because insects are drowned that would destroy the cranberry crop. The vines blossom in summer, and are generally in full bloom about the 4 th of July. The berries begin to ripen after the petals have fallen off. The flowers are small but very pretty. The petals are white, tinged often with pale pink. The stamens are bright orange, the flower stem deep crimson, the buds are quite pink, the leaves bright, glossy green. If the flower were larger, it would probably be cultivated for the beauty of its flowers. In the fall, the berries are ready for harvesting using either wet or dry methods. Online Resources: Sample file The University of Massachusetts Cranberry Station provides an excellent overview of how cranberries grow, including a detailed diagram of the life (production) cycle of the cranberry, available here: http://www.umass.edu/cranberry/downloads/nathist.pdf The Wisconsin State Cranberry Growers Association has made excellent educational videos titled Wisconsin Cranberries: Growing Strong and Wisconsin Cranberries: Not So Wild Anymore available here: http://www.wiscran.org/about_cranberries_0002/video_0027.html You may also learn more about cranberry bogs, harvesting and the inventor of cranberry bounce test here: http://www.oceansprayfoodservice.com/about/where.aspx
Drawing 1. Make a drawing of a whole berry, of a cross section, and of a vertical section. 2. Sketch one of the plants using the pictures and illustrations provided. Show the stem, leaves, bud, blossom, and the stem that runs along the ground and bears the roots. Lab Report Throughout this lab, you have been answering questions and writing down notes in the spaces provided. You may use these notes and answers to write up your lab, in other words, write a lab report. In completes sentences, explain what the purpose of the lab was, what materials you used, what you did, and why you did it. Explain your results including any drawings you made (label them) and a short explanation about what is shown in each drawing. In conclusion, explain what you learned. If you would like, you may use the cranberry-themed notebooking pages provided to write up your report. Sample file