When my mother was a kid (she's 93 in 2006) the grocery stores didn't
sell pectin, or if they did, her parents either couldn't afford it or didn't
know what it was. Whenever they made jelly from a fruit that was low in
pectin, they added apples to supply the needed ingredient. Then when I was
a kid growing up in the forties, I remember jams as being nothing more than
fruit cooked to the consistency of mush, without regard to pectin content,
and jellies of any kind of fruit AND apple. It was 1950-something before
Mom ever used store-bought pectin.
Nowadays, we, at Brambleberry Farm, manufacture no-sugar spreads for
those who need to restrict their sugar intake. We use xylitol for a
sweetener in most recipes because it is a naturally occurring sugar
substitute (one method of producing xylitol is to extract it from the inner
bark of Birch trees). Since sugar alcohols (sugar substitutes ending
in -ol) can produce a laxative effect in some people, we use unsweetened
apple juice, not for the pectin it may contain, but to mask the tartness of
some fruits. The addition of apple juice allows for a pleasant product with
a minimum of xylitol content.