Help With Lab Report-Yeast Fermentation on Artificial Sweeteners

[Tobel]

In my molecular biology class we performed an experiment where we tested the rates of alcohol fermentation by measuring the CO₂ collected in the tops of the fermentation tubes of different sugar solutions.

Our solutions we tested were: glucose, apple juice, sucralose (Splenda), aspartame (Equal), and a 1% starch solution. 

The glucose, apple juice, and aspartame were the only ones to show any signs of fermentation. Glucose produced the most, apple juice and aspartame averaged the same amount but apple juice began fermentation more quickly than aspartame. I'm now on the discussion portion of my report and I have absolutely no idea why aspartame fermented (in all three trials) yet sucralose didn't. 

 

I've researched and all I can really come up with is that dextrose (d-glucose) is a component of Equal, and that the yeast is fermenting that. I've gathered that Equal is 180-200 times sweeter than sugar while Splenda is 600 times sweeter, so I figured maybe there's more dextrose in the Equal while the Splenda has such a minimal amount that fermentation didn't happen. 

 

If anyone can shed any light on this, pleaseeeee help. It's driving me crazy.