My daughter is 15 months old and she did the same thing (sometimes still does). Sometimes, you just have to take a step back and try not to make it a battle. If my daughter pitches a fit like that, then I calmly take her out of her high chair and tell her that her dinner is there when she is ready to eat (or breakfast, lunch, whatever). My pediatrician recommended this because she said that the one thing these little guys have control over is what they are (or aren't) going to put in their mouths. You can't force them to eat, so just let them get down and when they are hungry enough, they will eat it. It is really hard the first couple of times and I had to put her in and out of her chair several times before she realized that she wasn't going to get anything different. (She would have lived on hot dogs and macaroni and cheese every day if I kept giving in to what she wanted) The bottom line is that you have to put a meal in front of them and let them decide if they want to eat it or not. Trying new things is hard for them, but I was having the same problem you did in that she would refuse to eat something that I know she loves and as soon as she did take a bite she would say "mmmmm!"
As hard as it was the first few times to let her go a little hungry, she finally figured it out and now we don't have too many of those days anymore. She may start to whine a little and I just tell her that she doesn't have to eat it if she doesn't want to, but she knows nothing else is coming along behind it, so that is her choice. She does much better now and eats lots of different foods, so it does get better.
I also noticed recently that my daughter's appetite has become more like a toddler's. Some days she will eat a ton and some days I wonder how she isn't totally starving because she will hardly eat at all. Sorry for rambling...I guess the bottom line is not to force food. All it does is get everyone worked up and it really doesn't help in the long run. I went through about a month of what you're describing before I realized that it wasn't worth it to keep forcing the issue. Good luck!