The students explored some of the properties of eggs this week, including how lecithin, a fat like molecule (phospholipid) found in the yolk can serve as an emulsifier, bringing together oil and water mixtures because of its hydrophilic head and hydrophobic tail.
We began by observing how water and oil interact (or don't) in mason jars in small groups. After shaking them the students noticed that the oil and water immediately separated. We then watched this video which explains why water and oil don't mix. The video used the metaphor of dancers on a dance floor. Another video explained how lecithin works as an emulsifier. The structure of the lecithin forms a barrier that prevents the fat droplets from coming into contact with other droplets. With this knowledge in hand, the students were asked to tell a short story through images and/or words, creating characters for oil, water and lecithin and describing how lecithin was ultimately able to bring the two together. We also added egg yolks to our initial oil/water mixtures but noticed no matter how hard we shook them, the water and oil would separate. Thinking we needed more yolks, we continued to add but the results were the same. The next day, we combined the mixtures with a small hand blender and our emulsion was complete.
0 Comments
Leave a Reply. |
Archives
May 2019
Categories |