Sounds like they are pretty average, they stick their beaks up at a lot if they aren't particularly tame or just don't know that its food yet. It took awhile for mine to understand the concept of yogurt but now that they know what it is, watch out! all dignity is lost when it comes to yogurt.
Mine are super picky as well. A lot of people say that chickens like lettuce but mine won't touch it. One of mine won't even eat the new brand of chicken feed I got, so I have to go and buy the old kind again.