Influence of sugar composition in yoghurt on sweet receptor activation and sensory sweetness perception

Sweetness is sensed by sweet taste receptor heterodimer (TAS1R2/TAS1R3) which responds to sucrose, glucose, fructose, and galactose. Limiting added sugar in dairy foods while maintaining sweetness for palatability is important in healthy food design. We investigated the influence of sugar composition in yoghurt on sweet receptor activation and on subsequent sensory sweetness perception. We found that sweet receptor activation was enhanced by the addition of sucrose post-fermentation to Yoflex® yoghurts (CH-1 Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and YF-L811 Lactobacillus rhamnosus, Lactobacillus delbrueckii subsp. bulgaricus). Sensory evaluation by trained panellists supported these findings. Analytical profiling revealed variability in residual sugar composition, particularly galactose. Receptor assays revealed a novel potentiating effect of galactose on sucrose-induced receptor activation. Sugar type and composition are key determinants of yoghurt sweetness and can be predicted by in vitro sweet receptor assays to determine sugar synergies as a strategy for minimising added sugars in dairy products.