PRESERVING FRESHLY CUT FRUITS

Researcher: Rachel Sutcliffe

Abstract

This study was about how to preserve freshly cut fruits, in this case apple slices. There were four groups of five apple slices. One group was set out on the counter, another placed in a gallon baggie, another covered in lemon juice, and one in the refrigerator. Each group was weighed every thirty minutes for twelve hours. The hypothesis suggests that the group of apple slices covered in lemon juice would be the best at preserving the fruit, by losing the least amount of weight. After the experiment was completed, the gallon baggie was proven to be the best at preserving the apple slices, and the lemon juice was proven the worst at preserving the apple slices.

Review of Literature

Ethylene Harmless gas Can not be smelled or tasted Fruits and vegetables produce this gas

after they have been picked If two foods that produce ethylene are

close to another the gas speeds up the ripening process

Enzymes Special protein Starts a chemical reaction

Review of Literature (Continued)

Decomposition Small organisms break down

food Depends on what kind of

bacteria or fungi gets to the food How decomposition works is

varied and depends on how much light, the temperature, and moisture

There are signs of decomposition/the fruit being spoiled (example: fungi appears fuzzy)

Question, Problem, Hypothesis Research Question: What is the best

way to preserve cut fruits between on the counter, in a gallon baggie, dipped in lemon juice, or in the refrigerator?

Hypothesis: If a cut fruit (apple) is on the counter, in a gallon baggie, dipped in lemon juice, or in the refrigerator, then the cut fruit (apple) that is covered in lemon juice will be kept fresh for a longer amount of time.

Experimental Design

Experimental Design includes the elements listed at the right.

The list to the right is what is coming up.

Materials List Set Up Variables

Control Group Experimental Group Independent Variable Dependent Variable Constant Variables

Procedure

Materials List

2 Gala apples (relatively the same size and weight) Apple cutter 5 plates Scale Camera Lemon juice in a small bowl One gallon baggie Flat surface/counter at room temperature

(thermostat set at 68˚F) Refrigerator (40˚F) Sink

Set Up

Variables

Control group Cut fruit (apple) that is on the counter.

Experimental group Cut fruit (apple) that is in the gallon baggie, dipped in

lemon juice, and in the refrigerator. Independent variable

How the cut fruit (apple) is being stored. Dependent variable

The weight of the group of cut fruit slices (apple) and how the fruit looks.

Constant variables The apples used (type, size, weight), the type of plate

used, scale.

Procedure1) Wash the 2 apples with water.

2) Get one plate and put one apple on the plate and use the apple cutter.

3) Repeat step 2 using the same plate for other apple.

4) After both apples is cut, put 5 slices on each of the remaining four plates.

5) Weight and record each group of apples slices with the plate (constant error). Make sure there is a piece of paper identifying the group of apple slices on the counter and lemon juice.

6) Place a plate on the flat surface away from the other plates.

7) Put one plate with the apples slices in a gallon baggie and leave on the flat surface/counter.

8) Dip each slice of apple from a different plate in the bowl of lemon juice (make sure to let excess juice drip off before putting the slice back on the plate) and leave on the flat surface away from the plate with lemon juice.

9) Put another plate in the produce drawer of the refrigerator by itself (no other fruits should be in the drawer during the experiment).

10) After thirty minutes come back to each plate, weight the group of apple slices, and record measurements taken on a data table. Make brief observations of the group of apple slices and write down in a composition book and take pictures of each group of apple slices.

11) Repeat step 10 for twelve hours.

12) After the experiment is completed put all the apple slices in the gallon baggie and throw away. Make sure to completely wash or throw away the plates.

Pictures

Beginning of Experiment

End of Experiment

*Pictures from left to right are counter, gallon baggie, lemon juice, and refrigerator.

Table

Apple Slices' Weight (grams)Time (minutes)

Storage Method 0 30 60 90 120 150 180 210 240 270 300 330Counter 241 241 239 238 238 238 237 236 236 235 234 234

Baggie 247 247 247 247 246 246 246 246 246 246 246 246

Lemon Juice 249 249 247 247 246 246 245 245 244 243 243 242

Refrigerator 242 242 241 241 241 241 241 241 241 241 241 241

Time (minutes)Storage Method 360 390 420 450 480 510 540 570 600 630 660 690Counter 233 232 232 231 230 229 229 228 228 227 226 226

Baggie 246 246 246 246 246 246 246 246 246 246 246 246

Lemon Juice 241 240 240 239 239 238 237 236 236 235 235 234

Refrigerator 241 240 240 240 240 240 240 239 239 239 239 239

Figure/Graph

Discussion

Table 1 (Apple Slices’ Weight) and Figure 1 (Apple Slice Weight Over Time) show that the gallon baggie preserved the apple slices the best. The refrigerator preserved the apple slices well but not as well as the gallon baggie. Tied for being the least productive at preserving the apple slices was the lemon juice and the counter. The lemon seemed to preserve the look of the fruit because in 240 minutes the apple slices had lost five grams of weight. The gallon baggie might have done the best because since the baggie was sealed it kept the evaporated water, from the apple slices, inside the baggie. Also, an observation made during the experiment was that the apple slices seemed to brown before losing weight. Possible errors that could have occurred were that the refrigerator was opened to retrieve the plate of apple sliced from the produce drawer so they could be weighed, and the family opened the refrigerator to get food and drink.

Conclusion

The data taken shows that cut fruits (apple slices) are best preserved in a gallon baggie. The hypothesis was not supported. The hypothesis suggested that the apple slices covered in lemon juice was the best way to preserve cut fruits (apple slices). This data can help out people in everyday life including parents packing a lunch for their child, or an adult or child wanting to package a snack for later use.

Future Studies

A couple of ways this experiment could be expanded is by testing other storage methods such as produce bags, plastic containers, and covering the cut fruit in honey. Also, other cut fruits could be tested for example strawberries, pears, pineapple, bananas, kiwis, peaches, and nectarines.

Acknowledgements

I would like to thank my parents, Brad and Jeannine Sutcliffe, and Mrs. Richards for guiding me through this experiment.

Bibliography

Barnes, L, & Romine, S. (n.d.). How to keep fruits and veggies fresh. Retrieved October 28, 2009, from Spark People website: http://www.sparkpeople.com/resource/nutrition_articles.asp?id=1103

Brain, M. (n.d.). How food preservation works. Retrieved October 28, 2009, from TLC website: http://recipes.howstuffworks.com/food-preservation.htm

Dalton, L. (2002, November 11). What's that stuff? food preservatives. Retrieved October 28, 2009, from Science and Technology website: http://pubs.acs.org/cen/science/8045/print/8045sci2.html

Food spoilage and additives. (n.d.). Retrieved October 28, 2009, from website: http://www.biotopics.co.uk/pot/foodsp.html

Microbiology of decomposition. (n.d.). Retrieved October 28, 2009, from Bottle Biology website: http://www.bottlebiology.org/investigations/decomp_bkgreading.html

Thrall, L. (n.d.). Why does food spoil?. Retrieved October 28, 2009, from Food Service website: http://www.foodservice.com/food_safety/fb6.cfm