Abstract/Summary

Replacing sucrose in baked products is challenging because of its unique contribution to texture and sweetness. Rare sugars like allulose and tagatose show potential as substitutes, displaying similar sweetness and acting as bulking agents. Although allulose and tagatose are epimers, it is unknown if they induce different behaviours on dough and biscuit characteristics. This study aimed to compare the impact of allulose and tagatose on thermal, rheological properties of dough, and on physical and sensory characteristics of biscuits. Four formulations were prepared using sucrose, fructose, allulose, and tagatose. Differential scanning calorimetry was performed on wheat flour-sugar solution mixtures, while rheological and texture analyses were performed on doughs. For biscuits, moisture content, water activity, dimensions, colour, texture, and sensory analysis were evaluated. Thermograms indicated that allulose and tagatose delayed the starch gelatinisation temperature (∼82 °C) but to a lesser extent than sucrose (94.5 °C). Doughs with tagatose were approximately 54 % harder than those with sucrose, reflecting in higher complex modulus values during early-heating stages versus fructose, allulose or sucrose. The lower solubility of tagatose led to more system mobility and water interactions with wheat flour polymers, resulting in biscuits with lower spreading (7 mm), hardness (14.3 N) and increased moisture (8.4 %) compared to sucrose biscuits (8.7 mm, 16.9 N, 2.7 %, respectively). Biscuits made with allulose and fructose demonstrated intermediate moisture (∼ 6 %) and diameter (∼ 7.4 mm), a high browning index (∼ 27.3), and texture similar to sucrose biscuits. These results suggest that despite having similar structures, allulose is a better sucrose replacer for biscuits than tagatose.