Praxis: Thanksgiving science
By Medicine Hat News on October 7, 2017.
What an amazing week — I hope you all survived the rather crippling blizzard we experienced earlier this week. I have to say that was some of the craziest winter weather I have seen in October. I cannot recall an October where there were snow drifts taller than me in my yard! Despite the snow and slow start to the week, it is shaping up to be a wonderful Thanksgiving weekend for all of us to enjoy with family and friends. I know that sometimes when we have a houseful of guests, some get restless. Well, look no further than here to put a little science into your Thanksgiving celebration. Just make sure you pick up a spare bag or two of cranberries! Happy Thanksgiving to all of my scientists out there. I know that I have a great deal to be thankful for and I hope you do as well. Let’s get started! *Remember to ask an adult before doing this experiment. Materials – cranberries – water – baking soda – cotton swabs – measuring spoons – measuring cups – two bowls – plain white paper – pot – stove – metal sieve – wooden spoon – long glass cake pan – blow dryer (optional) Procedure 1. Measure 500 mL (two cups) of cranberries and place in a pot. 2. Add 125 mL (one cup) of water. 3. Have an adult place the pot on the stove covered (as the cranberries will start to pop — listen!). 4. Allow the cranberries to cook for about 15 minutes. You want them to be soft and a bit mushy. 5. Remove the cranberries from the heat and allow them to cool. 6. Pour the cranberry mixture through the metal sieve. Push the berry mixture through with the wooden spoon. Make sure the cranberry mixture is quite runny just like juice you would drink. 7. Pour the cranberry mixture into the glass cake pan and set aside for now. 8. Make your secret message now. 9. Mix 30 mL (two tablespoons) baking soda with 60 mL (1/4 cup) of water. 10. Using the cotton swab, dip it into the baking soda mixture and then write on the white paper. Be patient, it takes a bit of time to get used to writing like this. 11. You can either allow your message to dry on its own or you can speed the process up by using a blow dryer. 12. Once the message is dry, 13. Place a sheet of paper into the glass cake pan with the cranberry mixture. 14. Look at your paper carefully. 15. Can you see the message you wrote? What is going on In this experiment, the pigments in the fruit changed colour when exposed to an acid or base. Cranberries contain anthocyanins which give them that bright beautiful red colour. This bright colour is important as in nature, plants need to attract insects, birds or animals to them. This is because the birds or animals will help spread the seeds from one place to another and allow the plant to continue to grow. These flavonoids in the cranberries change colour when they come into contact with acids and bases. In this experiment, the cranberries are very acidic. When you added the base or baking soda mixture to the cranberry mixture it should have turned a nice bluish purple colour. If you do not have cranberries, try this experiment with other kinds of fruit and let me know what happens! Do not forget about our annual Family Science Olympics is coming up on Oct. 14. This free family event will be held at Medicine Hat College once again. The day starts at 10 a.m. and will end at 3 p.m. There are a ton of prizes for scientists of all ages. Mark your calendars and please make sure you pop in for a little while or stay longer if you wish! I look forward to seeing you all there. Patty Rooks is senior scientific consultant at 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. 41-40
