Originally Posted by Machka

On my Randonneuring events, one of my favourite combinations is 100% pure orange juice plus a packet of beef jerky. You get your calories for energy, plus potassium and Vit C from the orange juice, plus sodium from the beef jerky, plus protein to help keep you going longer on the really long rides.

A convenient food with a very high level of potassium are dried apricots. A combination of dried apricots and salted almonds and you're set. I have used the combination on several of my long rides as well.