There's a difference between anthracnose and the ripening of the banana.. Just to be clear. They both visually affect the banana in the same sort of manner but there is a definite difference in whats really going on.
Here's a good publication that shows what anthracnose IS
There are, however, enzymes that react with the chlorophyll within the banana, essentially chewing it up - which is why the 'green' in a banana goes away. It's this same process, that swaps green-for-yellow, that inevitably sends the banana down the path to turning black.
WylieE did a pretty good job here hittin the nail on the head
"Enzymes present in fruits, mainly polyphenol oxidase cause the browning in damaged fruit. Normally polyphenol oxidase works in plants as a defense against insects. When activated this enzyme turns phenols in the plant into quinones, these quinones then turn into melanins which have beneficial properties to the plant- antibacterial, anti-fungal, and UV protection (another good reason to eat your fruits and veggies). Melanins are dark in color and so make the areas where they are present appear brown.
In healthy plant tissue the phenolic compounds are stored in the vacuole, well separated from the polyphenol oxidase enzyme so no activity happens. However, when a cell is smashed, cut, or otherwise tortured, the separating membranes are ruptured and polyphenol oxidase can access the phenolic compounds and start the process of turning them into quinones and then into melanins."
Now, with this in mind, remember that bananas produce their own form of a pectic enzyme, which is why as a banana ripens, it softens as well. This is a form of self-mutilation, basically 'smashing, cutting or otherwise torturing' its own cells to begin the ripening process.
It's this same rupturing of the cell walls that leads to the oxidation that I hinted at before.
I dont know why you'd have to see a weight change to acknowledge movement. There isnt any weight difference.
These guys did a study on it, among other things. Chemical compounds dont weight that much though..
There's more information here than you can read in a day
If you haven't, give this thread of mine a read.
Page 7 shows a blackened banana without any signs of anthracnose. The pages before, show the ripening process as well as some of the quotes I mentioned. I thought I had saved/linked to the papers I pulled the quotes for, I try to make it a habit, but I guess I didnt those couple times
You'll see that dehydration is a non-factor, as the banana actually becomes more liquid as it ripens.. If the banana gives off anything, its gas - ethylene. Definitely doesnt shed enough moisture to make up for the loss of thickness in the peel within my experiment though.
If you're still skeptical after the experiment I did, after the links I've provided and after finding some white papers on your own time.. All I can tell you is to go buy 40lbs of bananas and let them sit around for 3 weeks like I just got done doing.. Only had about 6 bananas with anthracnose on them, others had some white surface mold and crown rot but cant really expect anything less.
The rest of them blackened up amazingly well and I've made the best banana bread I've ever had from them.
Hope I didnt hurt your head too much
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)