I have a candy cookie bunny easter candy. The top 2 ingredients: Sugar and Partially hydrogenated palm kernel oil.
Since ingredients are listed by how much they make up of the product, there has to be a lot of oil in there. Yet the nutrition facts reads
Servings per container: 2
Total fat 11g
Saturdated fat 10g
Trans fat 0g
Aren’t all partially hydrogenated oils trans fats? I know 0g can mean anything under half a gram, but how can it be the second listed ingredient and not reach that threshold?
Note there is only 1 gram of unsaturated fat. Most of it is oleic, which only has one double bond and is cis. Trans fats occur when part of the multiple double bonds are hydrogenated. With only 2% of the oil being linoleic with 2 doouble bonds, you can’t make very much trans fatty acid.
Now corn oil with over 60% linoleic acid can produce high amounts of trans fat.
I don’t know why most naturally occuring oils are cis and why hydrogenation produces trans.
US labeling laws only require trans fat content greater than 0.5 grams per serving to be labeled as containing trans fat. Anything below 0.5 grams per serving can be labeled as 0 grams trans fat.
Whether or not a particular unsaturated fat has multiple double bonds is irrelevent to the production of trans fats. Trans fats come from the fact that the stepwise hydrogenation step is reversible. During the hydrogenation process the partially hydrogenated bond becomes free to rotate. If this molecule then goes back in the mechanism to the unsaturated version it can either go trans or cis. Since trans is the more stable of the two isomers, it could be the more likely product.
I think, to translate the lab speak: because palm kernal oil is already mostly saturated fat. If you can find it in the store (I can find it at ethnic markets), it’s a solid orange lump at room temperature.
When it’s partially hydrogenated, those hydrogen bonds only go to the (relatively few) unsaturated molecules, turning them into trans fats. The saturated ones are left alone and labeled as saturated fats on your label. There aren’t many unsaturated ones to turn to trans fats, so there aren’t a lot of trans fats.
And trans fats can be labeled 0 if there are fewer than 0.5g of them per serving, not per item. Your bunny is 2 servings, so may have as many as 0.99g (0.49999 *2) trans fats in the whole bunny and still be labeled 0.
That’s true of any unsaturated fat. The problem isn’t the saturated fat, it’s the incomplete saturation of the fat. It’s the partially hydrogenated fat. It would be possible, though not economical, to remove trans fat by 100% hydrogenating everything, but as with any chemical reaction, the rate slows as the reaction progresses.