Hey Blog! Last Monday, I went up to Sheffield for a new class all about science!
In Mad about Science! (23rd Nov. 23) I told you I rather like science. I also told you I did a few online classes with Amanda from Sparking Stem. However, I have never done an in-person science class – but that all changed on Monday when I did one!
Like the event last week, we had to get up very early… Then drive to Belper, get on the one train a day that runs direct to Sheffield and walk from the train station to the bus stop, wait for the bus, take the bus to the place where I was doing the class, and hang around for an hour. Luckily, there was a coffee shop nearby – all hail the great British coffee shops! What could we do without you?! Next, I entered the building and waited for the class to start.
The class was about testing for nutrients in foods, specifically proteins, lipids, sugars, and starch. These are tested for in different ways, using Biuret solution, Ethanol, Benedict’s solution and Iodine, respectively. Biuret solution is naturally blue, but if protein is present it turns purple when stirred. Ethanol is naturally clear, but in the presence of lipids it turns white when some water is added and the lot is shaken. Benedict’s solution is naturally blue of the same shade of Biuret, but creates a brick red precipitate when left in a 60°C water bath with the test sample containing reducing sugars. Iodine is naturally red-orange, but goes black if starch is present when applied to the sample. Using these four chemicals, some of which were a fire risk and all of which could kill you if swallowed too much (even a little could get you in hospital), you could determine exactly the molecules present in a sample of food. So that is what we did.
The first task was to find out what four unknown liquids contained: A, B, C, and D. Solution A came back positive for the lipid test, B came back positive for the sugar test, C came back positive for the protein test and D came back positive for the starch test. Well, that worked – quite straightforward if you think of it like that; the biggest difficulty was setting everything up and checking what to do with which reagent (the posh term for what you drop on something to tell you what it contains – like a rock dropped on someone’s foot is a reagent to see if they have a voice box – you can guess why!!!). However, once we had got the hang of that, we progressed to real food.
Here, I can best demonstrate with a photo. These are my results for the four tests – you can clearly see some of the colour changes that show molecular content. I can also show you the conclusions I drew as to the content of the samples (sorry for all the technical terms!):
I have two more sessions to do in-person, very soon, so I may write about those as well. I hope to do more in future, as it would be nice to do more of these excellent practicals!