The worst thing that can happen on level 598 is the fruit slipping down off the conveyor into the end column where there is no exit!
I have done this level several times and sometimes a cascade will set off and drop one of the nuts or cherries off the end of the conveyor and into the no mans land at the side.
You can possibly still salvage the game if that happens, but it makes your life a lot more difficult!
So try to drop the fruit off the conveyor in the middle of the board and avoid setting off cascades when they are on the ends of the conveyor..
Other than that a pretty simple level. Use the coconut wheels to clear some of the cream.
Level 597 has a conveyor belt running through the middle of the right side of the board. The candies move along from right to left and when they exit the right half of the board they re appear top left of the left half of the board.
While the left side is full of candies they move along the conveyor from left to right, but as the candies are destroyed they fall off the conveyor to the bottom of the board, one at a time.
I think the best way to deal with level 597 is to get the most powerful combos you can in the right side, maybe a colour bomb.stripe or wrap, while there are still candies in the left half, to destroy as much jelly as you can quickly.
This will also release the fish, which will clear quite a bit of jelly too.
Then finish off what's left with stripe/wrap combos and any remaining fish.
Once the candies are gone from the left side a colour bomb won't do much good unless combined with a stripe.