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The Effect of Irradiation on the Nutritive Value of Beef OBJECTIVE: The purpose of this experiment is to determine whether irradiation has an effect on the nutritive value of beef. The nutritional analysis will be made upon the content of protein in beef, which include nitrogen, and the content of lipids the beef contains. HYPOTHESIS: My first hypothesis is that the irradiated beef and nonirradiated beef will have the same amount protein and nitrogen level of nutrients. My second hypothesis is that the nutritional value of lipids in the irradiated beef will be less than in nonirradiated beef. PROJECT DETAILS: The manipulated variable in this experiment is the irradiated ground beef patties. The responding variables in this experiment are the protein content and nitrogen content in the beef patties, and the lipid content in the beef patties. MATERIALS: 1 Nonirradiated Ground Beef Patty 1 Schwann's Irradiated Ground Beef Patty 1 Licos Machine 6 Aluminum Containers (Part of the Licos Machine) 2 Electronic Balances 6 40mL Beakers 5 125mL Flourence Flasks 2 Spatula 4 Stirrers 1 Filter 1 Clamp 1 Burrette Stand 1 Pippette 100mL Hexane 200mL Isobutyle Alcohol 125mL Sodium Hydroxide 8mL Sulfuric Acid PROCEDURES: Part 1: Setting Up the Licos Machine: 1. Open up the computer program for the Licos machine. 2. For the first three test group, label them “rad”. This will be the irradiated beef patty. 3. For the second three test groups, label them “nonrad”. This will indicate that this beef patty does not contain irradiation. 4. Under the protein factor, label 6.25 grams for each test group. 5. Under sample moisture, label 55.00 percent for each test group. Part 2: Protein and Nitrogen Content 1. Take a small sample of the nonirradiated beef patty and place it in a 40 mL beaker. 2. Mix it by itself for about 2 minutes so the proteins can be balanced out between the beef. 3. Turn on the electronic balance and the small aluminum container on top of it. 4. Balance out the electronic balance and take the aluminum container off. 5. Place about .16 grams of the nonirradiated beef patty from the beaker onto the small aluminum container with a small spatula. 6. Mass the aluminum container with the nonirradiated beef patty on the electronic beam. 7. Record the mass of the nonirradiated beef into the computer program for the Licos machine under mass. 8. Now, place the little aluminum container into one of the open slots on the Licos machine. 9. Repeat steps 3-8 for the proceeding 2 nonirradiated test groups. 10. Repeat steps 1-2, but instead of using part of the nonirradiated beef patty, use part of the irradiated beef patty. 11. Repeat steps 3-8 for the irradiated test trial of the irradiated beef patty in the beaker. 12. Once all the test groups (nonirradiated and irradiated beef) are placed in open slots on the Licos machine, press the analyze button on the machine. 13. The Licos machine will then analyze the nutritional content of proteins and nitrogens found within the meat by burning it. 14. Once the Licos machine has analyzed the protein and nitrogen content of one test trial, it will record it on the computer program. To read the protein and nitrogen content of the sample, look under Protein percentage and Nitrogen. Record the information onto your data. 15. Repeat step 14 for the remaining test trials. Part 3: Titration of the Lipids 1. Get four 40mL beakers and label them from 1-4. Two of the four beakers will contain irradiated beef and the remaining two will contain nonirradiated beef. 2. Take a 40mL beaker and place it on top of the electronic balance. 3. Balance out the electronic balance so it read 0 grams with the beaker on top of it. 4. Place about 5 grams of nonirradiated beef into the 40mL beaker with a small spatula. 5. This beaker will be label number 1. 6. Repeat steps 2-5 for the following: - 1 more beaker with nonirradiated beef. This beaker will be labeled number 2. - 2 beakers with irradiated beef. These beakers will be labeled number 3 & 4. 7. Take the four beakers and place them on top of the counter. 8. Place about 25mL of hexane into each of the four 40mL beakers that contain beef. 9. Mix the hexane with the beef in each beaker for about 5 minutes each, so the fat in it can be exposed out of the beef. 10. Take four 125mL flourence flasks and label them 1-4. 11. Take beaker number 1, which is nonirradiated, and drain the hexane from the beef into flourence flask number 1. 12. Dispose the remaining beef and set the beaker aside. 13. Repeat steps number 11-12 by the following: Beaker number 2 drained in flourence flask number 2 etc. 14. Take a clean flourence flask and make a solution of the following: - A. Place 25mL of hexane with 50mL of isobutyl alcohol and two drops, which equal about 1mL and is the base, of sulfuric acid and mix it together in the flourence flask. - B. In the pipette place some sodium hydroxide in it. - C. Then, place the flourence flask under the pipette and slowly add some sodium hydroxide into the mixed solution. Keep the solution constantly stirred. - D. When the solution changes to a pink/purple color, then your solution will be ready and the solvent will be about 1.1mL. - E. This solution will be used as a sample color of how the titration of the lipids of the beef should be. 15. Take flourence flask number 1 and place 50mL of isobutyl alcohol into the solution and two drops of the base, which is sulfuric acid. 16. Repeat step number 15 for the remaining 3 flourence flasks. 17. Place 125mL of sodium hydroxide into the pipette. 18. Take flourence flask number 1 and place it under the pipette on the burette stand. 19. Record the starting point of the sodium hydroxide in the pipette. 20. While stirring the solution in the flourence flask, release some sodium hydroxide into the flourence flask and mix with the solution. 21. Continue step number 20 until the solution changes into a pink/purple solution like your example in step number 14. 22. Once the solution has changed into a pink/purple solution, record the amount of sodium hydroxide it took to change from the start to finish. 23. Set the flourence flask aside. 24. Repeat steps number 19-23 for flourence flask numbers 2-4. 25. To find the amount of sodium hydroxide each sample took, subtract the starting point of the sodium hydroxide from the finish point and that is the amount of lipids the sample beef had (both for irradiated and nonirradiate).