There should be no problems with dehydrated ground beef over the short term. I have jerky that has been stored at room temperature for months that is still good. When I dehydrate ground meat, I first marinate it in something salty like Worcestershire sauce, then thoroughly cook it, rinse it with boiling water and dehydrate it. I normally get about 25% of the weight that I started with. After that, I vacuum pack it and freeze it. Frozen, dehydrated ground beef should last practically forever. When I dehydrate, I keep the meat separate from the rest of the meal ingredients. This is partly so that I can interchange the ingredients for more variety, but also to avoid contaminating the meal with spoiled meat. I think that the real concerns with dehydrated ground beef are rancidity and loss of nutrition due to oxidation rather than spoilage. I've experienced oxidation over the long term, but not rancidity.