Oil v.s. Butter (or margarine) in baked goods
1) If a baking recipe calls for oil, can it be substitude with melted butter or melted margarine and vise versa?? If so, what will be proper portion, 1:1 or ??
2) What kind of oil is considered a healthies oil for baked goods in terms of non-GMO product and also low fat? Seems olive oil is not recommened for baking due to its strong flavor may change the baked goods.
3) What kind of oil can serve as all-purpose oil to be used in baking, cooking, stir-fry?
I prefer butter to oil and I have an intense dislike of margarine, and I substitute butter for all other oils 1:1 in all my baking unless it makes no sense to do so. I've never had a problem doing so. Most margarine is vegetable oil prepared in certain ways, so yes, absolutely, margarine can be substituted for oil.
The only concern I've had - which is something that has never actually been an issue - is that a swap in oil types could change the salt balance, e.g. using salted butter in place of vegetable oil.
I don't know about healthy oils or what not, but I very much like corn oil for my non-butter needs (e.g. stir frying, etc).
1) Sometimes, for things like muffins you can substitute. It won't be exactly the same but workable. If you melt the butter, I would do 1:1. Oil is higher in fat than butter (which has liquids). I wouldn't do it for cakes and cookies.
2) Healthy is in the eye of the beholder. I would never use margarine. You can bake w/ extra light olive oil, not any lower in fat than EVOO or the others, but lighter in flavor. There is no real low fat oil since oil is fat.
3) I use either light olive oil, if I'm cooking at a higher temperature or EVOO if I'm not.
margarine contains trans-fats, which we now know are dangerous. i never cared for the taste or texture anyway, so have always used butter in recipes that call for it.
in the u.s. most vegetable oils, including corn and canola, are made from gmo crops. so is anything soy based. safflower is probably your safest bet there. there are cake recipes that use olive oil, but unless you use extra light, the flavor will come through in other desserts.
butter and oil all are about 100 calories per tablespoon. unless you use some sort of processed frankenfood, none of them are low fat.
there is a way to replace some of the oil or butter in baked goods with applesauce or prunes, but i have never done that.
there are inexpensive blends of canola + olive oil available, that might be a good choice for you if you want only one oil in your pantry for savory cooking. but the different fats offer different flavor and it's worth having a few -- i most commonly use butter, olive oil and sesame oil, then peanut oil to fry.
Getting into more details, the grams of fat per serving of butter vs different oils is one issue but there is also the breakdown of sat/mono/poly fats in each. I'm not convinced about naturally occurring sat fats because that much worst for you (one reason I said healthy is in the eye of the beholder) but this is a good breakdown of fats:
I also don't buy canola oil because it's not a naturally occurring fat and, as you said, can be GMO. I think, in this case, "healthiest" can be a loaded question and there isn't a simple answer.
i concur, and am not fat-phobic in any way. it's what carries all flavors through recipes and through your palate. it also helps you feel sated.
over the walk-in at the french laundry is a sign that says: "fat is flavor".
most diners would be aghast to know how much butter and oil is used in restaurant food.
Grapeseed oil is my oil of choice for sautes and stir-fries. It has a very high smoking point relative to most other oils. Avocado oil is excellent for these purposes as well. In recipes for baking that call for oil (and also for vinaigrettes) I prefer safflower oil. I never deep-fry, so I'm no help to you there.
Traditionally in the Deep South, peanut oil is used in baking in lieu of butter or lard because of it's prevalance. It has a neutral flavor and high smoking point. Joy of Cooking is likely the best resource in cookbooks I know for your type of substitution question, but while certain types of fat do produce better results in certain recipes, pastry for example, I would think you'd be safe most times substituting 1:1. Guage your results and adjust accordingly. I got creative several years ago and decided to use applesauce and the like to replace shortening.... and produced pudding so many times I just gave up!