I've seen that some people who can/bottle make pectin from apples. I've also seen that some recipes call for pectin but I didn't know what it was or why I would want to use it. So I asked my mom. She didn't know what or why either... other than her mom used it. :-/
I told my mom that if I was going to go through the effort of making and canning my own jam, I wanted to make sure I knew what I was putting in it. She told me to have fun with my research and let her know what I discovered. lol.
So off to the Internet, I went...
According to Wikipedia, pectin is a structural heteropolysaccharide contained in the primary cell walls of terrestrial plants.
It's been a while since I've had any chemistry training, so I can't say I exactly know what a heteropolysaccharide is, but at least it's not from Extra-Terrestrial plants. That would be difficult to source. ;-)
According to PickYourOwn, pectin reduces cooking time for jams and jellies and allows you to use less sugar. I'm not sure I buy the less sugar claim, but getting peaches to the jam stage with pectin takes a lot less time than getting peaches to the butter stage without pectin.
Pectin also has an entry on WebMD. lol.
I also consulted a couple of books in my library and a few other websites that I don't remember.
Essentially pectin is a fruit-based complex-carbohydrate that can be used as a thickening agent and is apparently good for resolving diarrhea.
I feel better now. Don't you? ;-)