Bananas don’t behave like electrolytic capacitors. Their dielectric is essentially a wet, resistive layer, so the capacitance is tiny and highly frequency‑dependent, around 0.02 µF at 1 kHz and dropping further at higher frequencies. If you just drop a banana into a RC network, the voltage will rise slowly, then collapse once the electrolyte leaks, and the waveform will be messy and unpredictable. I’d log the voltage with a high‑bandwidth scope and compare it to a 100 µF reference; the banana will show a huge droop and no stable hold. Intuition might say “fun experiment,” but the data will prove that fruit isn’t a proper energy storage element.

You're right, a banana only adds a messy resistive path. Stick with electrolytics for real charge storage and keep the breadboard off the fruit counter.