Abstract
The market of gluten-free (GF) products has been steadily increasing in last few years. Due to the technological importance of gluten, the GF food production is still a challenge for the industry. Indeed, large quantities of fat, sugars, structuring agents, and flavor enhancers are added to GF formulations to make textural and sensorial characteristics comparable to conventional products, leading to nutritional and caloric intake imbalances. The formulation of the novel “clean-label” GF bread included a commonly used mixture of maize and rice flour (ratio 1:1) fortified with selected protein-rich flours. Naturally hydrocolloids-containing flours (psyllium, flaxseed, chia) were included in the bread formulation as structuring agents. A type-II sourdough was obtained by using a selected Weissella cibaria P9 and a GF sucrose-containing flour as substrate for fermentation to promote the exo-polysaccharides synthesis by the starter lactic acid bacterium. A two-step protocol for bread-making was set-up: first, the GF sourdough was fermented (24 h at 30 °C); then, it was mixed with the other ingredients (30% of the final dough) and leavened with baker’s yeast before baking. Overall, the novel GF bread was characterized by good textural properties, high protein content (8.9% of dry matter) and in vitro protein digestibility (76.9%), low sugar (1.0% of dry matter) and fat (3.1% of dry matter) content, and an in vitro predicted glycemic index of 85.
Link to Full Text
Key Points
This study aimed at optimizing a formulation and breadmaking procedure to obtain a novel “clean-label” GF bread. The formulation of the recipe was based on the selection of different ingredients naturally characterized by (i) high protein content, (ii) structuring properties, and (iii) high sucrose concentration, this latter able to promote the in situ EPS production by the selected Weissella cibaria P9. The bread made with the optimized production protocol was characterized for the main technological, nutritional, and sensory features. The formulation of the novel “clean-label” GF bread has been optimized by using (i) a mixture of corn and rice flour (ratio 1:1); (ii) quinoa flour (10%) as a source of protein, and (iii) psyllium, flaxseed, and hydrated chia (6%) as structuring agents. Moreover, a type-II sourdough, which was obtained by using a selected Weissella cibaria P9 and chestnuts flour as a sucrose source to promote the in situ exo-polysaccharides syntheses, was included (30% of the final dough) in the bread formulation. Overall, the novel GF bread was characterized by good textural properties, high protein content (8.9% of dry matter) and in vitro protein digestibility (76.9%), low sugar (1.0% of dry matter) and fat (3.1% of dry matter) content, and an in vitro predicted glycemic index of 85. Moreover, common sourdough bread features, i.e., acidic taste and darker color of both crust and crumb, were identified in the “clean-label” GF bread. This work demonstrates that a proper selection of raw materials (unprocessed flours), together with the use of traditionally inspired biotechnology, allow the production of high-quality bread, meeting the demand of the modern consumer for novel clean-label GF products.