Experimental mixture design to ameliorate the sensory quality evaluation of extra virgin olive oils

Composite products of the agro-food industry are commonly obtained by blending two or more ingredients in order to improve the sensory quality of the final mixtures. In this paper four virgin olive oils coming from different cultivars and processes have been considered. The sensory evaluation of the tasters (panel test) has allowed the selection of the best mixture by using a mathematical model with linear parameters calculated by regression. The employed special cubic model has pointed out a net synergistic effect in the response contour plot of a three-component mixture when the worst olive oilʹs concentration is excluded. By increasing its concentration the sensory responseʹs volume decreases slightly in the composition tetrahedron, and that indicates that the synergism among the three best olive oils can widely compensate the effect of the worst one.