delta mix

Question

on a recent delta flight, they were serving this packaged snack without a hechsher. i read the ingredients and by line five or more it mentioned romano cheese. can one assume that at that point the cheese is batel? someone once taught me that if a goy is mixing kosher and treif for himself it is if it is mixed up by accident by a Jew? And even if this is true, given the fifth line, can one assume that it is only an infentismal amount of cheese? thank you