Introduction: TVS mud index1) is a tensiometric marker for quality and maturation process control of Italian Euganean Thermal Muds (ETM) which sensitivity defined on objective basis their quality and maturation degree. Objectives: The goal was to assess the maturation process of Biofango by TVS mud index (Sanraku-en spas centre, Japan and Osservatorio Termale Permanente-OTP, Italy), and its organic compounds by TOC analyses (University of Padova, Italy). Materials and Methods: Biofango was prepared using KomatsuClay, MotoyamaClay, WakuraDiatomite and KasaokaBentonite giving K02 (Bentonite 1.25, Kaolinite 1.5, Diatomite 0.25) and A01 (KasaokaBentonite 1.25, Kaolinite 0.5, Diatomite 0.25). Final Biofango BFM+0%Dolomite, MAT1+10%Dolomite, MAT2+18%Dolomite, and MAT3+35%Dolomite were analyzed by TOC (Perkin-Elmer-2400) and DSA10-Krüss employing (a) PFPE, Fomblin HC/OH-1000, diiodomethane, glycerine as liquid tests and (b) Owens-Wendt mathematical model for conversion of contact angles in surface energy parameters2). Results: The behaviour of C(%) in MAT1, MAT2, and MAT3 during maturation process (20°C) showed respectively (a) MAT1t0h=1.26%, MAT1t216h=0.91%, MAT1t360=1.08%, MAT1t576h=1.23%, MAT1t720h=0.98%, (b) MAT2t0h=2.36%, MAT2t216h=1.80%, MAT2t360=1.49%, MAT2t576h=1.86%, MAT2t720h=1.68%, (c) MAT3t0h=3.29%, MAT3t216h=2.71%, MAT3t360=2.57%, MAT3t576h=2.6%, MAT3t720h=2.7%. C% decrease demonstrating the influence of Dolomite in Biofango mixtures. Dispersed energy components (DC) of MAT1, MAT2, and MAT3 showed respectively (a) MAT1t0h=3.0mN/m, MAT1t216h=3.1mN/m, MAT1t360=2.9mN/m, MAT1t576h=3.8mN/m, MAT1t720h=2.5mN/m, (b) MAT2t0h=2.1mN/m, MAT2t216h=2.2mN/m, MAT2t360=3.1mN/m, MAT2t576h=3.7mN/m, MAT2t720h=2.6mN/m, (c)MAT3t0h=2.0mN/m, MAT3t216h=2.6mN/m, MAT3t360=2.6mN/m, MAT3t576h=2.9mN/m, MAT2t720h=3.0mN/m. On the other side TVS mud index showed respectively (a) MAT1t0h=68.7mN/m, MAT1t216h=70.26mN/m, MAT1t360=71.78mN/m, MAT1t576h=64.69mN/m, MAT1t720h=71.84mN/m, (b) MAT2t0h=74.06mN/m, MAT2t216h=71.69mN/m, MAT2t360= 70.36mN/m, MAT2t576h=65.83mN/m, MAT2t720h=71.23mN/m, (c) MAT3t0h=75.9mN/m, MAT3t216h=73.05mN/m, MAT3t360=73.34mN/m, MAT3t576h=68.52mN/m, MAT3t720h=68.66mN/m proportionally inverse with DC behaviour. MAT3 with highest content in Dolomite demonstrated great capability to uptake DC during maturation process with consequently decrease of TVS mud index levels accordingly with TOC result. Conclusions: Tensiometric investigations of Biofango underlined the links between chemical and surface energy data. The high sensitivity of TVS mud index consented to follow directly in a non invasive way the structural-surface changes in Biofango mixtures occurred during maturation process opening at new perspective for their control.