Praxis: Using your head to make apple heads
By Patty Rooks on September 21, 2019.
praxis@praxismh.ca@PraxisMedHat As I am writing this column I can see my backyard out the corner of my eye. There are so many beautiful fall colours beginning to pop out. It is always hard to say goodbye to summer, but fall has a beauty all of its own I believe. One thing that has also caught my eye is all of the apples on my trees. What to do with them all? Silly question, some science experiments of course. Let’s get started! *Remember to ask an adult before doing this experiment. Materials – apples – apple corer – knife or vegetable peeler – lemon juice – measuring cup – measuring spoons – salt – baking tray – bowl Procedure 1. Have an adult help you remove the skin from the apples you want to use. You may want to also carve faces in the apples and put them out for Halloween decorations – they are pretty awesome once the experiment is completed! 2. Measure 250 mL (one cup) of lemon juice and pour it into the bowl. 3. Measure 15 mL (one tablespoon) of salt and add it to the lemon juice. Mix this well. 4. Take the apple and roll it around in the lemon juice and salt mixture. 5. Place the apple on the baking tray. 6. Repeat with as many apples as you want. 7. Place the apples in a warm sunny location and allow them to dry out. What is going on? I am sure that you know once you cut an apple it quickly turns brown. This is because there are iron containing chemicals in the apples that turn brown when they react with the oxygen in the air. This reaction is called oxidation — very similar to why iron will rust. Adding lemon juice to the apple allowed you to preserve the apple and kept it from turning too brown and rotting. The lemon juice you added is acidic and this lowered the pH of the apple. The acidity prevented the enzymes in the apple from allowing the bacteria to make it rot. Salt is also important because salt helps preserve food; literally sucking the moisture out and shrinking up those once juicy apples. I would love to see some pictures of your apple heads! Email them to me at the address below. Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. You can find us at: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca. 27-26
