Tubefex worms are a very low quality food anyhow. Pellets are much more nutritious. As far as freeze dried foods being less nutritious than frozen that's not quite true. You do lose some vit. C in the freeze drying process but it concentrates the nutrition in the process (losing the water), fish can eat more of a freeze dried product so they actually get more nutrition from them.
A very good freeze dried food to try is freeze dried blackworms. They are true segmented aquatic worms and have much more nutritional value than bloodworms or tubifex. You can feed them as a sole food source if you want (many discus people do just that). There are 2 sources, Al over at simply discus sells Australian blackworms (http://aquaticsuppliers.com/Freeze-D...riginal_c6.htm
) or Dan at California blackworm (http://www.blackworms-are-here.com/
). Email either of them and they will send you a free sample that will last a single betta quite a long time. My bettas go nuts over them and also eat NLS 1mm pellets. I feed both daily.