Gellan F is a thickener made from seaweed. You use alot like gelatin but the biggest difference is you can heat the product and it won't break down. I have tried to make a noodle like the Parmesan noodle at el bulli. The problem is is that he uses agar and when I made it taste like shit. When they make it it probaly taste amazing. The gellan leaves no flavor in the food. On our current menu we are making a green apple noodle with watermelon and red curry chicken. The noodle is easy to make ounce you get the portions right. That is the delema with this cooking style. You have to find the time to figure it out. I must have made it 100 times to get the ratio right. El bulli has a line of chemicals that you can buy. The only problem is they have mixed the chemicals for there applications. What if they don't carry that product any more. I recommend buying chemical in there purest form. Then you can come up with ratios that will always work for you. Here is the apple noodle recipe
95g green Apple juice
5 g Glucose
1.2 g Gellan F
Juice about 4 green apples. Let the mixture set for 5 minutes. Scrape off all of the brown solids from the top. Weigh out the Apple juice and place the gellan on top. Blend with a hand mixer. Place in a saucepan with the glucose. Heat the mixture until it boils for 1 minute. Take a large syringe and fill it with the Apple mixture. Place a plastic tubing on the end and push the juice through. Place in ice cold water for 1 minute. Push the noodle through using the syringe.