Color-changeable chewing gum indicates the type of masticable food

Abstract

Abstract Purpose: Masticatory performance is confirmed with color-changeable chewing gum that changes yellow-green to red when chewed. Previous studies have used a colorimeter to reveal the cut-off a* values of the gum’s color (a* represents the degree of color between red and green) to determine which foods are masticable (masticable meat, masticable soft side dish, and inadequate masticatory performance). Since a more convenient method is required, we examined the validity and reliability of visual measurement using the existing color scale to indicate masticable foods by observing the chewing gum’s color. Methods: Fifty patients aged ≥ 65 years were enrolled. Using color-changeable chewing gum, three groups were formed according to the cut-off a* values: masticable meat, masticable soft side dish, and inadequate masticatory performance. For the color scale classification, one physiatrist and dietitian simultaneously, individually, visually determined the chewing gum color and classified it as belonging to one of the three groups. Criterion-related validity was evaluated using the kappa coefficient of agreement between the results from the two methods. Inter-rater reliability was examined using the kappa coefficient of agreement between the three groups judged by the two raters on a color scale. Results: The kappa coefficients of the agreement for the classifications were 0.908 and 0.909 for the physiatrist and dietitian, respectively. The inter-rater agreement between two raters on the color scale was 0.938 for the kappa coefficient. Conclusion: The color scale indicated the masticable foods without a colorimeter. This method can be useful in older adult facilities and homes.