Food test (yr 8)

[ana.santos]

Hi all,
Has anyone done basic food test (from Science Focus 2) prac for yr 8? I just want to know where to buy the materials such as testape, albustix paper and vit C solution. Thanks.

Ana

[cheltie]

We just use lemon squeeze bought from the supermarket for Vit. C.
The Testape you can get from the chemist but I don't use the other one so not sure.
Helen

[smeee]

If you are doing the prac on page 86....
Test 2 : We test glucose with Benedicts solution
Test 4 : Protein....Try egg white with Biuret - teacher demo only because of 10M NaOH
Hope this helps

[noona]

We only use 1M NOah and Cuso4 never used 10M before remember to only add as you are doing the prac

[Loopy]

We use Uristix for both glucose and protein. I crush up Vitamin C tablets and add distilled water for Vit C.

[ana.santos]

Thank you for the replies, such a big help, really appreciate it. I suggested to a teacher to use different chemicals such as biuret reagent (10% NaOH and 0.5% copper sulfate) and benedicts for protein and glucose test instead of testape and albustix ,but he's not agreeable as these are for seniors (biology) and not for juniors.

Where did you order the uristix Loopy?

[rae]

We always use benedicts and biuret for year 8. Really easy!!

[smiley]

Any chemist can sell you Uristix etc, esp those that cater to diabetics. Or check with your local Health Dept and ask a Diabetes Clinic directly.

[Loopy]

We buy Uristix from Southern Biological, but mind you, they are not cheap! Best of luck!

[Lyn]

Test for protein using 1M NaOH and 1M CuSO4 (or 0.5M or 0.2M CuSO4). The stronger CuSO4 solution works quicker. Gives a really nice purple colour with milk. Some foods have to stand for a while (ie cheese) before you get some mauve colour. Some foods go a dark blue before eventually getting to the mauve stage. We use benedicts solution for glucose. Instead of students heating the glucose and benedicts solution over a bunsen we have a large beaker of hot water on the teachers bench that the students put their test tube with the glucose and benedicts solution into. The solution will eventually go varying shades of orange. Or the students could set up all their test tubes with a solution of each food and several drops of benedicts at their desks in a 400ml/500ml beaker and the teacher will bring a jug (electric) of hot water to the student's bench and put hot water into each beaker. This means that the students are not moving around the room with beakers of hot water. If you don't have the Uristix, Testape or Albustix on hand, the above is the simplest option and less expensive.
Lyn.