The three factors most likely to increase demand are consumer income, consumer tastes, and the number of consumers.
As there come to be more people in the world, there are more potential consumers of orange juice. This will, all other things being equal, raise the price of orange juice.
People in the world are also becoming richer in general. This may mean that more and more people will be able to afford orange juice. This will increase demand for orange juice.
Finally, orange juice can simply become more popular. There is no guarantee that this will happen, but if consumers simply come to like orange juice better than other options demand will rise.
When demand rises, all other things being equal, prices rise.