Sugar not only provides the desirable sweetness but its reduction can also alter the physico-chemical properties of foods. The objective of this study was to evaluate the effects of tagatose as a sugar substitute on selected physico-chemical properties and sensory acceptability of strawberry-flavored yogurts. Six yogurt samples with decreasing concentrations of sucrose (8.50 to 1.70 g/100 g) and increasing concentrations of tagatose (0.00 to 9.24 g/100 g) were evaluated. Physico-chemical tests (pH, lactic acid (%), °Brix, water-holding capacity (WHC), viscosity, and color) were conducted to examine the quality and shelf-life of yogurts during 28 days of storage at 4 °C. An acceptability test (n = 55) was conducted to evaluate the sensory characteristics of yogurts. Sucrose reductions by the replacement of up to 80% tagatose showed marginal effects on the selected physico-chemical properties; however, the loss of red color (a*) and increase in yellowness (b*) of the tagatose-substituted samples were significant. Strawberry yogurts with tagatose replacements had similar acceptability scores for all attributes. Sucrose reduction showed a positive effect on the purchase intent of the strawberry yogurts (an increase of 3–30%). These findings can be used to understand the effects of tagatose/sucrose formulations on the acceptability and physico-chemical properties of yogurts.

BACKGROUND There is an increasing demand for reduced‐sugar products due to the worldwide prevalence of obesity, diabetes, and cardiovascular diseases. The aim of this study was to evaluate the effects of sugar (sucrose) reductions on the acceptability, preference, and quality of strawberry‐flavored yogurts. A consumer rejection threshold test and an acceptability test (N = 53) were conducted using six yogurt samples with decreasing concentrations of sugar (12–5/100 g). Additional physicochemical tests (pH, °Brix, water‐holding‐capacity, viscosity, and color) were conducted to examine the quality and shelf‐life of strawberry‐flavored yogurts with reductions of sucrose during 28 days of storage at 4 °C. RESULTS Reduction of sucrose affected the acceptability and physicochemical characteristics of yogurts. The consumer rejection threshold showed that sucrose in strawberry‐flavored yogurts could be reduced to 5.25/100 g from an initial concentration of 12/100 g without affecting the preferences of consumers. The 71%‐sucrose (8.50/100 g of yogurt) was perceived as the most liked (6.27 using a nine‐point hedonic scale) and the most preferred (rank sum = 127.50) yogurt sample. For the physicochemical properties of yogurts, the viscosity (3263–5473 cP) decreased, and the color lightness (80.98–85.44) increased during 28 days of storage at 4 °C. CONCLUSION Physicochemical properties and preferences were affected by the reduction of sugar. The consumer rejection threshold analysis showed that sucrose can be reduced to less than half of the initial concentration. These findings are useful to understand consumers' acceptability and shelf‐life of yogurts with reduced‐sugar formulations in the developing of new products. © 2020 Society of Chemical Industry

This study demonstrates that manufacturers met their labeling claims for ephedra-free products. Special attention should be given to the presence of heavy metals and other drugs like caffeine, synephrine, and botanical sources of caffeine as these ingredients have replaced ephedra.