Boy, this really gets into some heavy science! If you want to read some articles that compare butter vs margarine - here
is the result of a google search on the topic. Of course - the answers for which is best go both ways, some based on scientific facts and some on opinion.
This is just a 25-cent tour:
Fats (from any source) stimulate the body to produce cholesterol. The bad cholesterol is LDL, the good cholesterol is HDL. Only oils made from animal fats actually contain cholesterol.
Saturated fats raise the levels of LDL, mono-unsaturated fats lower LDL, and poly-unsaturated fats lower both the levels of LDL and HDL. So, and oil high in monounsaturated fats, with a minimal level of poly and saturated fats (like olive oil) is better for you than one low in monounsaturated and high in poly and saturated fats.
The molecular chain for saturated fats is rather straight; unsaturated fats are curved, bent, or spirals (CIS configuration). When mono-unsaturated fats are hydrogenated
- the chain straightens out (TRANS configuration) to look
like a saturated fat chain - so the body treats it like one.
RE Trans-Fats: The big deal is this - for years nutritional information on packages didn't include the info on the conversion of CIS monounsaturated fats to TRANS configuration. So, while we looked at the nutritional into for the lowest saturated fat (to eat healthier) we were not aware of the amount of monounsaturated fat (which should be good for us) that was affecting our body the same as saturated fats.
Why did they do this? Saturated fats are more shelf-stable than unsaturated fats. By converting the monounsaturated fats into TRANS configuration - they had the longer keeping qualities of saturated fats - without the label scare. Yes, it was a matter of "legal" deception. The TRANS fats were still chemically
As for the melting points of margarine ... it really depends on the oil and the emulsifier. Since butter-flavored hydrogenated vegetable fats (margarine) have come under scrutiny due to the trans-fats issue - some manufactures have changed how they make margarine. Some use an emulsifier such as lecithin, some use gums, some use gelatins - the oil and emulsifier additions are whipped and butter flavored - the emulsifier holds the oil in a solid state at room temperature. Some margarines were/and may still be based on a mix of animal and vegetable fats (especially oleomargarine
), not pure vegetable fats.
As auntdot noted - margarine is the "poor man's" butter substitute
- but that is another study in history (war time, depression era, economics, etc) ....
I, personally, have not allowed margarine in my door for 25 years unless it was called for in a baking recipe.