I know there are a couple of common ways to make the gelled liquid noodles that are forced through a plastic tube submerged in ice water with a syringe (like the El Bulli spaghetti kit for the iSi). I've mainly observed them made with either agar agar or gellan gum. What I never liked about these versions was the texture. The gel is too brittle, and the noodles can break fairly easily... besides, it's not the right chew and that interfers with the philosophy of making good food.
Using water, I tried a few percentage variations using agar agar combined with locust bean gum and xanthan. I ended up with a ratio that gives very soft and palatable noodles with a good deal of strength. The noodle came out in one piece and could repeatedly be picked up and handled without breaking. It also had a fair amount of heat resistance. 20 to 30 minutes under the heat lamp resulted in a warm toothsome noodle.
There is only one mentionable downside to the formula... syneresis. When sitting around for a few hours after gelling the noodles, there was a noticeable increase in the amount of liquid released into the dish. Not sure how to get around this yet, although the liquid broth released was very clear and very tasty... just need to work it into the dish as well I guess.
The noodle below was made with water only (0.4% agar, 0.25% LBG, 0.2% xan).
hot chicken noodles... slurpin' goodness