How to use YouTube API with Gulp (minified file doesn't contain YouTube callback methods)

I can't use YouTube Player API methods because they are deleted by Laravel Elixir (Gulp) in my minified .js file.

Methods such as below are not included in my my minified .js file because they aren't called in .js files I created (In fact, they are called in YouTube iFrame API).

onYouTubeIframeAPIReadyonPlayerReadyonPlayerStateChange

Any solution for this problem ?