Evaluation of Palatability of Foxtail Millet Congee Based on Granular Structure of Foxtail Millet Starch

Abstract

This study aimed to explore the relationship between the granular structure of foxtail millet starch and the palatability of foxtail millet congee. The palatability and starch granular characteristics of congee from 10 cultivars of foxtail millet were analyzed and the effect of the latter on the former was evaluated by correlation analysis. A predictive model for the palatability of foxtail millet congee was proposed by stepwise regression analysis. The results showed that small granules accounted for a high percentage of foxtail millet starch together with a low percentage of tiny granules, and the Barrett-Joyner-Halenda (BJH) pore volume of foxtail millet starch granules was small, resulting in low gelatinization conclusion temperature (Tc) and fast gelatinization rate and finally good palatability of congee. The amylose content, gel hardness and gelatinization temperature range of foxtail millet starch were significantly negatively correlated with the sensory score of foxtail millet congee (P < 0.01), while the gel viscosity, elasticity, cohesiveness, gumminess, chewiness, resilience and initial gelatinization temperature were all significantly positively correlated with the sensory score for palatability of foxtail millet congee (P < 0.05, P < 0.01). The granular structure of foxtail millet starch indirectly affected the palatability of foxtail millet congee by affecting the key physicochemical properties. There was a significantly negative correlation between the proportion of small starch granules and Tc (P < 0.01) and gelatinization temperature range (P < 0.05). The proportion of medium starch granules had a significantly positive correlation with Tc (P < 0.01), and the proportion of large starch granules had a significantly positive correlation with the water-binding capacity of starch granules (P < 0.01). Finally, the predictive model for the palatability of foxtail millet porridge was developed using the gel cohesiveness, amylose content, proportion of tiny granules, gelatinization temperature range and Brunauer-Emmett-Teller (SBET) of foxtail millet starch as independent variables, and the correlation coefficient between the predictive score and the sensory score was 0.998 (P < 0.01). The above results can provide a theoretical basis for the selection of foxtail millet suitable for cooking and processing in China.

Keywords

• foxtail millet starch; foxtail millet congee; granular structure; palatability