Altering baked goods by the addition of nutrient-rich ingredients, such as soy and ground almonds, affects the water and lipid distribution of the product and, subsequently, its final quality. Here, we studied how three lipid sources, shortening, canola oil, and ground almonds, affected texture and water distribution in a baked soy pretzel and the molecular mobility in the dough. Pretzel crumb from all formulations exhibited 40-43% moisture with a little more than half present as "freezable" water. Firmness and chewiness decreased with increased shortening and canola oil, whereas firmness and chewiness increased with additional almonds. In contrast, neither springiness nor cohesiveness was affected by the lipid quantity or source. Finally, magnetic resonance imaging of the soy pretzel dough revealed two or three populations of dough components that have distinct molecular mobilities. With increased lipid content, the mobility of each population increased in magnitude and heterogeneity. Interestingly, almonds had the smallest effect on the molecular mobility of the dough but had the largest effect on textural properties. These results provide quantitative insight into the mechanisms by which the lipid source can influence molecular properties that have textural implications for bakery products.
Keywords: almond; bread; lipid; magnetic resonance; physical properties; pretzel; soy.