Question: Is using iodine a good way to determine if rice grains are real or are merely bits of plastic?

liz is asking a question about question
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by liz | January 04, 2017 18:32 | #13836

What I want to do or know

I was asked by community members "how can i tell if rice grains are actually rice, or, as sometimes happens in parts of the world with less stringent food inspections, if the bag is full of rice-shaped bits of plastic?"

Discussion so far

In conversation with @gretchengehrke and @warren we discussed the iodine test for food starch that would turn rice purple. See


It would be important to do the test also with plastic. Perhaps bio-plastics made from corn for example would also have the purple reaction.

Here's what we want to know

So my questions are, 1) what do you think of the iodine method? What's the easiest method for doing this? 2) can you think of any other methods for determining the authenticity of rice? For instance, what about burning the grains, or seeing if they float in water, or if there's enough time, seeing if cooked/boiled grains become moldy?


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