The levels of variation of each component were determined in preliminary tests. In the conching stage of the chocolate production, we observed that the cocoa butter reduction had to be limited
to 50 g/100 g so that the mixture of all chocolate ingredients could be processed. Therefore, so were the maximum limits of each of the two other components (50 g/100 g). The design consisted of eight formulations, one being a repetition of the central point in order to verify the standardization of the process by calculation of the experimental error. The samples were identified by the letters CB,IN or BG representing cocoa butter, inulin or b-glucan, respectively, followed by numbers showing the concentration of the added fibre in the chocolate formulation, as is showed in Table 2.