Making lemon juice gel for cooking I often make tilapia fillets in the oven. I put two pieces of fillet on an oiled Corelle plate, put some lemon juice, salt and basil on it, and cook it at 170°C for 15 minutes.

This is my routine breakfast, so I've cooked this meal over a thousand times now. I love the taste of lemon juice on the fillet, and I don't like how most of the lemon juice just collects at the bottom of the plate rather than sticking to the fish.

I was thinking, is it possible to add something to the lemon juice to give it a gel-like texture? If it's viscous like that, maybe I can just spread it on the fish, and have a nice thick layer of lemony taste.

I looked at gelatin, agar agar and Gellan Gum. The first two seem to not be able to withstand high temperatures (I need 170°C). There's a page about Gellan Gum here and it says "Hydrates between 167-203°F/75-95°C, Gels from 50-122°F/10-50°C, Melts from 176-284°F/80-140°C". I'm not sure what that means though.

Can you think of a solution to make lemon juice be more like a gel, and withstand 170°C?
You could make a lemon curd. 

It will not be baked at the same time as the fish, but could be a good way to do what you want,

See this recipe.

https://www.geniuskitchen.com/recipe/cod-fillets-with-an-asian-lemon-curd-glaze-164296