Sweet solutions: influence of flour:water:sugar ratios on sweetness perception in liquid and semi-solid model foods

In the context of reformulating sweet bakery products to maintain sweetness with reduced sugar, the role of basic formulation constituents, such as flour, in sweetness perception remains unclear. This study investigated composition effects on sweetness perception in model systems composed of two levels of breadcrumb flour (BF), water and sucrose. Model foods were designed where the viscosity was matched for either the whole system (WS) or only for the water phase (WP), by using Xanthan gum. This was tested with two sugar levels (3% and 6%) and two food systems (liquid and semi-solid). Sensory analysis (n=30) assessed perceived sweetness and thickness through a rank-rating methodology. Overall, sweetness was lower in semi-solid than in liquids (p < 0.001), and lower in 3% than in 6% sugar (p < 0.001). Higher sweetness was observed for higher concentration of BF in WS samples, but no difference in sweetness in WP samples (interaction WP/WS x BF level: p < 0.024). This effect was consistent in both sugar levels and both food systems. Thickness perception was stronger correlated with the viscosity of the whole system (liquid: r = 0.98, semi-solid: 0.99) than with the viscosity only in the water phase (only semi-solid (r=0.77)). Consequently, thickness perception did not correlated with the sweetness perception. This is the first study that underpinned the importance of the viscosity of only the water phase rather than the whole system on sweetness perception within a food system.