Structured fat–water–fiber systems as fat substitutes in shortbread formulation: modulation of dough characteristics following a multiscale approach

The use of “fat substitutes” is trending upward in food industry to meet dietary recommendations and to respond to the increasing number of health-conscious consumers. In this frame, a multiscale approach was applied to study the effect of structured fat–water–fiber systems on shortbread dough quality. Several formulations (n = 9) were designed based on three structured fat–water–fiber systems at different fat levels (15%, 20%, and 23%), three conventional fats (butter-B, palm oil- PO, and sunflower oil-SO), and three combinations of conventional fats with structural emulsions (at 20% fat and 20% water contents). The partial substitution of B and PO by the structured emulsions resulted in moister, less sticky, and softer doughs. Structured emulsion-based doughs exhibited higher structural stability (higher tan δ) than those made with conventional fats. 1H nuclear magnetic resonance (NMR) revealed significant differences in water dynamics, where doughs containing structured fat–water–fiber systems (richer in unsaturated fats) were characterized by a more rigid population, while those rich in saturated ones (B and PO) had more mobile protons. Overall, this multilevel screening emphasized the usefulness of 1H nuclear magnetic resonance in monitoring the molecular differences among the different formulation (which were less evident at mesoscopic and macroscopic levels), as confirmed by multivariate statistics.