Can you point me to the respected rabbinical authorities who hold you can't?
I don't know your guidelines for respect, rabbinic, or authoritative
but there was quite an argument at the OU between R' Shachter and R' Belsky until R' Genack was machria.
The lenient argument is simply that it wasn't included in the gezeira, while the strict argument is that it fits all the parameters of the reasons for kitniyos (looks like grain, is ground like grain, and is processed with grain- to the extent that unless it bears a reliable hashgacha, you muat check it for grains.)