Yes, though it's not as straightforward as it seem, for two reasons. First of all, Factorio already has a way to tweak spoilage rates through startup settings, and the range is quite wide. Secondly, I CAN tweak spoilage rates after the fact, but I'd need a concrete ruleset to do it by. It's simple enough to just slap on a multiplier, but it runs into the risk of pushing some fast-spoiling recipes to near-zero values, as well as pushing some longer-spoiling recipes into integer overflow.
Ahhhh, I see. Is it necessarily a multiplier, or would you be able to set discrete units like for example say bioflux takes 6 hours to spoil, but you could set nutrients to 1 minute if you wanted to? The reason I mention it is because there are things that spoil that potentially shouldn't due to the way they limit certain playstyles.
That already exists in Mod Settings. It's called "Excluded Items" and allows you to tag items to be excluded from the mod entirely. This is more or less the entire reason I made my own spoilage mod, as this feature was requested but not available in other mods (that I could find). Does that do what you want? And if not, could you explain what you're trying to accomplish in a bit more detail?
So sorry! Should have been more clear. In the mod I linked there is a list of items you can check mark and un-check mark in the settings. It simply was a suggestion for a quicker way for the player to select the items they want to choose more easily :) I have configured it as provided and it was mostly painless :P
edit:
Essentially, I guess I'm suggesting to have a list of items and a blank space where you can specify the length of time (0 for no-spoilage or something) that all the spoilable items take to denature :) The fermentation station is fantastic as well, that way you can really set up some interesting loops and potentially even add support for spoiling things intentionally potentially on other planets. Like maybe a paleo-bacterium needs to be mixed with bioflux spoilage to start a stone cycle on Gleba, or a heavy oil eating bacterium that can convert the oil on Fulgora to rocket fuel or something!