Effects of the type of reference scale on descriptive sensory analysis of cooked rice: Universal aromatic scale versus rice aromatic scale

This study aimed to determine whether panelists' attribute-intensity ratings and performances in descriptive sensory analysis could vary with the type of reference scale used. Seven panelists, three times each, evaluated flavor attributes of eight cooked-rice samples using either the universal aromatic scale (UAS) or the rice aromatic scale (RAS). Both scales could differentiate cooked rice samples with respect to individual flavor attributes, although the RAS was more sensitive to several attributes such as cardboard and metallic flavors. While both types of reference scale exhibited good repeatability, the RAS demonstrated better performance in terms of panel agreement and discriminability than did the UAS. Both scales produced similar clustering of cooked rice samples based on flavor attribute intensities. In conclusion, while either type could be effectively used as a quantitative frame of reference in descriptive sensory analysis of cooked rice, the RAS performed better than the UAS with respect to detecting and scoring subtle sample differences in flavor attribute intensities. Practical applications Despite its popular use as a quantitative frame of reference in the descriptive sensory analysis for a broad range of products, the UAS has the limitation that panelists may use only a narrow range of the entire scale when products to be tested have either very low or very high intensities. This study showed such a limitation in several flavor attributes of cooked rice samples with typically weak flavors. Our findings provide a better understanding regarding how choice of a quantitative frame of reference influences descriptive sensory analysis of cooked rice.