What plant was this?

There was a plant growing along my grandmother’s house in Florida many years ago. It produced only a few of what I guess was its fruit, which looked somewhat like a pinecone, except it was soft and fleshy and a rusty red color. What was interesting is that when you squeezed this fruit, it smelled exactly like soap, and if you lathered this liquid up between your hands it produced suds exactly like soap too.

Anyone know what plant I’m talking about? It’s been twenty years, so my memory is a little hazy.

Just guessing, Googling around on “tropical fruit soapy” and “fruit saponin tree florida” and things like that.

Bitter melon? Was it a vine?
http://www.rain-tree.com/bitmelon.htm

Star apple?
http://www.hort.purdue.edu/newcrop/morton/star_apple.html#Description

Soapberry? Although the fruit is a berry.
http://doacs.state.fl.us/~pi/enpp/94-1&2all.htm

Picture of soapberry tree.
http://www.hortpix.com/pc3870.htm

Picture of soapberry fruit. Small round berries, though, not pine cones.
http://www.biosurvey.ou.edu/shrub/sasad.htm

Is it possible you’re conflating two different trees, maybe the soapberry with some other semi-tropical fruit?