In theory salt creates a hypertonic environment when it is added to a solution.
What this means is that when salt is added to the water in which your particles is being soaked, it creates an environment where there is relatively speaking more salt(ions) than fluids(water molecules). it should in theory draw the fluids out of the particles. This in turn will cause them to take longer to soak and cook.
In plain language, salt might cause your particles to take longer to soak and cook. However I haven't noticed anything inparticular, but maybe there is someone who can give practical evidence.
Cheers