That's not the kind of knowledge you get just from being given an order to seem interested in something. [Most people don't know in-depth the health benefits of even things they eat regularly, let alone the variety of offerings on the table here. Maria won't deny that some of the shinki are off, but this one doesn't seem like one of them.]

Shinki native to this world don't like to start trouble. They're very polite, unlike you. Not to mention there's the risk of angering a god if, for some reason, they actually took your side on this.