Can I use "我知道“ to say I know some kind of food? There are kinds of foods, such as malaxiangguo, that people often suspect a foreigner will not know and will not like. I can say "我吃麻辣香锅" (wo chi malaxiangguo).  Is that the best thing to say?  And I have used both 知道 (zhidao) and 认识 (renshi) to say I know various foods.  I think I have heard both used, but I may be wrong about that. 

Anyway, all have worked, but what is the best way to say this? 

This was not clear enough.  The common case is that I am trying to buy some kind of food and the seller is concerned that as a foreigner I do not know what I am doing and cannot like that kind of food.  Seven years ago in Beijing this could happen if I just started to use the red pepper paste at the table, and 我吃辣 worked as reassurance.  Spicy is a lot more common in Beijing now.  But it happens a lot with 羊杂 of any kind.  

If the seller asked me a question about whether I knew or wanted the food, of course I would use the same vocabulary to answer. The Chinese grammar of questions and answers is a very good system. 

My problem is what to say when the seller is just visibly uncomfortable.  Seven years ago some would rush over to my table as I opened the pepper paste, warning "辣！辣！“  Now if I order, say 肚 (du3, tripe, a normal ingredient in pepper pot soup and hog's maw in Pennsylvania when I was a child, though many Chinese and Americans today do not know it was ever eaten in the US) shop owners often look dubious.  I did not intend that pun.

I am sure the advice against using 认识 is correct, and 知道  is not perfect.  But even those poor choices have worked to reassure, which is my goal. I'd just like to say it better.
Usually don't use 我认识 on food, if someone ask you whether you know of some kind of food, if you have eat it once or more, you can say 我吃过那个. or if you ever heard of it, you can say 我听说过，但是没吃过. If you want to eat, you can say 我们可以吃吃, if you don't, just say 我不想吃 or 我不喜欢吃那个.
If you are on table, and someone show you a kind of food, and ask you do you know it, he may ask you 你知道这道菜是什么吗？Then you can say 我知道 or 我不知道，and 我认识 or 我不认识 can also use here. But, this is not a polite action, man usually don't ask others not close enough for this sentence. Ask for 吃过这道菜没有 is a more common question.