The application of statistic thermodynamic principles to the biosynthesis of inulin explains the synthesizing and degrading activities of the fructan:fructan fructosyl transferase (FFT) enzyme as well as the molar mass distribution of native inulins. The direction of the FFT enzyme action is energetically forced by maximization of the mixing entropy of the polymeric distribution of inulin. The entropy maximized polymeric distribution of native inulins corresponds to the most probable distribution for linear polymers (Flory-Schulz distribution). Estimating the energetic need of the FFT enzyme from in vitro experiments and applying it to in vivo conditions provides an explanation and an accurate prediction for the molar mass found for native plant inulins in vivo.
