The Study on Sweetness Enhancement Design in Augmented Reality Based on Synesthesia Theory

Taste is influenced by both the food's inherent taste and its visual appearance. Previous research shows stable synesthesia between visual features (e.g., color, shape) and taste perceptions (e.g., sweetness, sourness). However, past studies mostly relied on 2D images and taste-related words, which may limit their practical application. This study uses augmented reality (AR) to overlay virtual 3D dessert images onto real desserts. Participants tasted the virtual desserts and rated their sweetness, liking, and congruency. The findings revealed that desserts with rounded shapes and fewer visual elements were perceived as sweeter than desserts with angular shapes and more elements. Smooth textures also enhanced perceived sweetness compared to rough textures. These results suggest that AR technology could enhance sweetness perception without increasing sugar, offering potential benefits for individuals controlling sugar intake. This approach also presents new design opportunities in the food industry by expanding AR's application in multisensory experiences.