Efecte dels additius i la temperatura en la reologia del puré de patata

Considering that potato puree is rich in starch, some of the rheological properties of this product have been studied in order to advance in new technologies such as 3D printing. The material used was the commercial puree and the effect of the preparation temperature of this puree was analyzed, comparing samples elaborated at 40oC and 100oC together with the effect of agar and alginate additives at different concentrations 0,2%, 0,4% and 0,6% in the parameters of viscosity, thixotropy and elastic limit. The results obtained have confirmed that the mashed potato is a non-Newtonian fluid and that the interactions between the hydra colloids (agar and alginate) and the starch granules of the mash create a network that increases the viscosity, the thixotropy and the limit elastic of the starch. According to these results, it has been seen that low concentrations of additives, inhibit the swelling of starch granules, limiting the access of water within them and, as a consequence, reduce the viscosity, thixotropy and the elastic limit of the mixtures; while higher concentrations (0.6%) generate the opposite effect. The effect of the preparation temperature of the samples on the rheological properties of the mash has also been verified; in samples prepared at 100° C the starch has gelled, while the samples prepared at 40 C, it hasn't gelled. Regardless of the concentrations of the additives, the samples prepared at 40 °C have shown values of viscosity, thixotropy and elastic limit lower than the samples prepared at 100 °C. Thus, it has been observed that both agar and alginate demonstrate their ability to affect potato mash and stabilize it. Even so, it has been seen that the agar causes a greater effect, since it is with the clearest starch granules breaking and with which higher viscosity, thixotropy and yield values are achieved. Thanks to this study, the effects that additives and different temperatures can exert on the starch structure of commercial potato mash and its rheology have been known, in order to improve the use of mashed potatoes in advanced food technologies such as it can be 3D food printing.