What the heck is interesterified oil and why is it in my tortillas?

I was in Fred Meyer last week picking up some things for school lunches & I needed tortillas for black bean and pumpkin burritos. There were no tortillas in the organic section but I frequently buy non-organic tortillas frozen at Costco so I headed to the 'regular' part of the store. I located the tortillas and began reading labels. Since our government refuses to allow the peons to decide for ourselves whether or not we want our corn genetically modified I had to assume that all the corn, corn meal and corn flour included was GMO.  There were the usual unfortunate cast of industrial food players- partially hydrogenated oil, additives, preservatives, artificial flavors, corn syrup solids - but then I noticed something new: interesterified oil. I didn't know what it was and I wasn't going to experiment on my kids without some serious research. I ended up finding some minimally acceptable tortilla's in the fridgie section (white flour, safflower oil, salt) and went with those. Still not great but handmade tortillas were not in the cards that night.

After a week of having my life go swirling into crazy land (Miss V leaving for a trip, school stuff, big auction, nutso acting out and drama, knitting a stripey elf hat for T2) I finally got time to sit down and read up on this stuff. Yuck. I think I'll pass, thanks. The last thing I need is a new frankenfat that raises blood glucose.

Here are several links on the subject. All more comprehensive than my description.

here

or here

or here

or maybe this one