How to make a passion fruit mousse without gelatin? I am Brazilian amateur cook.

I wonder if there is any original recipe to make passion fruit mousse. Every time I do it, consistency is too runny and slightly aerated. Maybe the consistency to stay firm with the use of gelatine, but avoid using because I don't like to do it.

Most recipes that date make use of:


heavy cream;
sweetened milk and
passion fruit juice or pulp.


At the same time all mixed in a mixer or in a blender. Apparently, using too much juice or passion fruit juice is what brings more acidity and taste the result, making the more liquid mousse. I don't know if the climatic condition here change something.

PS: Use whipped cream would make the consistency of mousse more aerated and firmer too? What could I do (without gelatine) to make the mousse as expected?
There are two things you can do to make the mousse stiffer: 


Reduce the water from the fruit. So use some kind of concentrate instead of the pure fruit. For example, you could cook down a syrup or jam and add it to the mousse. Or see if dehydrating juice gets you somewhere. 
Use more fat. Instead of whipping cream at 30 to 35% fat, you could use double-cream at 45%, or a mix of cream and mascarpone. Or fold whipped cream (for aeration) and some cooked down passion fruit into something even stiffer. Maybe base it off a whipped white chocolate ganache.