Can I use oil in marinades for dehydrated mushrooms? I have a new dehydrator that I'm looking to use to replace some of my unhealthy quick snacks with better alternatives.  To that end, I think I've found a great base for alternative-snacking in dehydrated mushrooms--they have a mild, earthly flavor that could work great as low-calorie comfort-food with some spice or barbecue added to it.  I'm currently experimenting with making my own rubs for my mushrooms, but I'm stymied when it comes to marinating mushrooms before putting them on the racks.  

Most recipes I see for marinated vegetables utilize oil, and my understanding is that oil does not work well in dehydration.  Calorie concerns notwithstanding, the oil itself will not dry and thus the results will require refrigeration and have a short shelf-life. I'm really looking for something I can toss in the pantry to be eaten later when I feel like a snack without having to worry about it going bad, so this is a non-starter.

Should I worry about oil spoiling my vegetables?  Is there a good way to substitute a drying-friendly alternative for oil in recipes I find?
You can use oil in food you are dehydrating but you are correct that it will affect the shelf-life. The oil will become rancid before the dried mushrooms would have spoiled, but it will still be good for at least a few weeks and that can be extended to months, if you vacuum seal it.

If you want to avoid the oil, just skip it and use the spices in a bit of water (or diluted soy sauce, lemon juice, or vinegar). 

I haven't done dehydrated mushrooms, but I have made dehydrated spice mixes that contained some oil. They were fine and dried like anything else, but I didn't use a whole lot of oil in them.