Sudan III

[Graham Kemp]

Try it with various milks; such as non-fat, full-cream, et cetera.

Milk might be a problem because it is homogenised; there no seperation of fluid layers, thus making it less than ideal. It is also opaque.

A mixture of distilled water and cooking oil would possibly be a clearer demonstration. Mix to disperse the oil as droplets in the water, then add the dye and shake. The dye should stain the droplets brilliantly, and any excess should settle out of solution.

[nickykinz]

Yeah, I spoke to someone from Southern Biological. I think maybe I shook to much so the oil couldn't separate properly. I did another one and was more careful and that seemed to work a bit better. Its not a great test though for anything that doesn't form two layers. We were hoping to do a range of positive food tests and then give them something (like milk) to do the tests on. We are going to do bread now instead and use ethanol for the fat test.
Thanks

[rae]

We just use brown paper to test for fat content of food. Paper goes greasy and transparentish if food contains fat.