The optimization of the formulation for a chocolate cake containing inulin and yacon meal

The research aimed at determining, using surface response methodology, an optimal chocolate cake formulation when wheat flour was partially replaced with inulin and/or yacon meal. The yacon meal used in the formulation was prepared by using tuberous roots of yacon (Polymnia sonchifolia Poepp. & Endl.). The optimization indicated that a formulation with 20% of the wheat flour replaced with yacon meal, 153 mL of water and no inulin showed the best values for hardness (3.638 N), cohesiveness (0.691) and specific volume (1.86 cm(3) g(-1)). A formulation with 40% of the wheat flour replaced with yacon meal, 6% replaced with inulin and containing 126 mL of water showed similar values to the optimized formulation for the three responses mentioned earlier but, in addition, it had a greater content of fructooligosaccharides and inulin. Consequently, both formulations may give useful functional foods with physical parameters comparable with the control formulation.