Not too far in the future, when you reach for a healthy drink, it might be full of water from a cactus.

Your main course at dinner might be a pear-like fruit from Southeast Asia that does a remarkable job of imitating meat. The next candy bar your children bite into might be infused with mushrooms that help cut down on the sugar needed to sweeten the treat. And their breakfast cereal might be colored with algae instead of chemicals.

Why...