Partially hydrogenated oils, a major source of artificial trans fats, have been banned. Not all trans fats have been banned and they are not all artificial, they are also naturally occurring.
Jiffy corn muffin mix doesn't contain partially hydrogenated vegetable oils and contains zero grams of trans fats per serving (I have seen it claimed that products may have less than 0.5 grams per serving and round down to zero).
https://www.fda.gov/food/ingredientspackaginglabeling/foodad...