Off topic: I love the Jiffy Mix except last I checked it has trans fats in it. I wish they would remove that.
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...
They do also have a page for a Jiffy Baking Mix (no corn, sounds similar to Bisquick) that did contain partially hydrogenated vegetable oils, enough for one gram trans fats per serving.
[0] https://www.fooducate.com/app#!page=product&id=43DBDE62-E10F...
[1] https://www.fooducate.com/app#!page=product&id=43BFE144-E10F...