You may be able to freeze them and use them later although I think egg whites freeze better than yolks. I have some cookie recipes that use just the yolks. I'll often save up the whites from a cookie recipe in the ice cube tray in the freezer and when I get enough, make angel food cake with it. Was surprised, but frozen egg whites fluff/rise very well in angel food recipes. Cold egg whites can easily be whipped and they don't need to be at room temperature. They just need to be defrosted You can also use yolks in omelette or crepe recipes.
I guess I've been lucky with that. I actually like the lentil pastas. They aren't the same as the wheat based ones and they don't taste the same. However, I do like the taste of the lentil pastas in their own right. It is annoying though that most of the companies making gluten free elbow macaroni have decided to discontinue their products. Seems like as soon as I find a product I halfway like, it's discontinued.
The watermelon flour sounds really interesting. Do you make it or is there a good place to buy it? I've used flax and pumpkin seed flour in some recipes, but I just grind gluten free flax or pumpkin seed to make the flour. I use a coffee/nut grinder. If you come up with some recipes using the watermelon seed flour, I hope you'll share them. So far, I've been making apple pancakes just using teff flour. It seems okay. I put a little psyllium husk in to make it more fluffy. Haven't tried the white rice flour. Is it worth purchasing? I have the brown rice and sweet rice flours and figured that would be enough. I've seen several recipes on the Internet for waffles using sweet rice flour or mochi. I've been buying several specialty flours to experiment with but haven't found a lot of recipes I like with them. I have tigernut, chestnut and just bought okara to try. Found out okara doesn't work like soy flour. It has an interesting taste but very crumbly. I haven't been able to find a decent source of soy flour for years. Always on the look out for new and interesting recipes to try.
You may be able to freeze them and use them later although I think egg whites freeze better than yolks. I have some cookie recipes that use just the yolks. I'll often save up the whites from a cookie recipe in the ice cube tray in the freezer and when I get enough, make angel food cake with it. Was surprised, but frozen egg whites fluff/rise very well in angel food recipes. Cold egg whites can easily be whipped and they don't need to be at room temperature. They just need to be defrosted You can also use yolks in omelette or crepe recipes.