Application of multi-block analysis and mixture design with process variable for development of chocolate cake containing yacon (Smallanthus sonchifolius) and maca (Lepidium meyenii).

BACKGROUND: In this study, a chocolate cake formulation was developed with partial substitution of wheat flour by yacon and maca flour. A simplex-centroid design was applied to determine the proportions of the three flours, and the amount of water was included as a process variable at three distinct levels. According to the overall acceptability of the cakes, the tasters were separated into two groups using k-means.

RESULTS: After segmentation, regression models were constructed for overall acceptability of each group; R2 adjusted values of 92.5% for group 1 and 98.9% for group 2 were obtained. Using the sequential simplex method an optimized formulation was determined for group 1 (0.49 kgwheat kg-1 total flour , 0.37 kgyacon kg-1 total flour , 0.14 kgmaca kg-1 total flour and 140.0 mL of water) and another for group 2 (0.35 kgwheat kg-1 total flour , 0.65 kgyacon kg-1 total flour and 120.0 mL of water). In addition to these formulations, a third formulation was proposed with a greater maca proportion (0.32 kgmaca kg-1 total flour ), which does not significantly alter the overall acceptability of both groups. The three optimized formulations and two control formulations were evaluated through free-choice profiling. The data were evaluated using the multi-block method common components and specific weights analysis (CCSWA).

CONCLUSION: It was observed that a greater proportion of maca intensified brownness and burnt aroma and taste, whereas a larger proportion of yacon produced a better appearance, softness, sweetness and chocolate flavor. © 2017 Society of Chemical Industry.