VALORIZATION OF LESS COMMON GRAINS IN BAKED PRODUCTS THROUGH SPROUTING PROCESS.
Global population growth and climate change have heightened the urgency for sustainable food production and consumption systems. Although cereal grains and their derivatives are essential staple foods worldwide, the growing challenges faced by major crop yields highlight the need to shift toward underutilized crops to strengthen food security. These crops, despite their agronomic and nutritional benefits, face limited exploitation due to challenges such as restricted market demand, sensory limitations, and suboptimal techno-functional properties. Sprouting has emerged as a promising technology to enhance the sensory and functional attributes of grains. However, key knowledge gaps persist regarding the impact of sprouting conditions on macromolecular transformations and their downstream effects on flour functionality and product applications. In this context, this thesis aimed at: (i) elucidating the relationship between sprouting conditions, molecular changes, and functional flour properties; (ii) elucidating the impact of sprouting on dough rheology; and (iii) reformulating baked products with sustainable crops to promote innovative and eco-friendly food systems. In the case of oat, a literature review (Chapter 4.1) revealed that sprouting conditions—such as soaking time, sprouting duration, and stabilization methods—play a decisive role in determining the changes in compositional and nutritional traits of sprouted oat. However, there is a scarcity of research on the techno-functional properties of sprouted oat flour and its application in baked goods. Consequently, this work investigated the macromolecular changes induced by sprouting (Chapter 4.2). The findings indicated significant changes in proteins and carbohydrates, including an increase in soluble carbohydrates (e.g., oligosaccharides) and soluble proteins (e.g., peptides). These changes influenced thermal and thermo-mechanical properties, reduced viscoelasticity, and affected water mobility. Building on these findings, more complex systems, such as sponge cake (Chapter 4.3) and biscuit formulations (Chapter 4.4), were studied. For sponge cakes, the integration of 20% oat flour obtained from 48 hours-sprouted seeds demonstrated notable improvements in textural properties, also during storage. Similarly, biscuits produced with 20% oat flour obtained from seeds that were sprouted for 72 hours yielded optimal results, particularly enhancing friability. To broaden the scope, sprouted buckwheat was explored for cracker and bread formulations and the effect of sprouted buckwheat-enrichment was compared on two types of wheat systems, characterized by different gluten strength (Chapter 4.5). Crackers produced by incorporating up to 30% sprouted buckwheat were comparable to their wheat-based counterparts, while bread formulations tolerated up to 10% enrichment. Higher incorporation levels (20–30%) in bread resulted in structural challenges, likely due to disruptions in gluten network formation, which impaired texture and overall quality. Finally, to overcome this challenge, the potential use of different milling fractions from sprouted chickpea was addressed (Chapter 4.6). By manipulating particle size, and specifically by using grits, this work demonstrated improvements in dough rheology and bread structure, enabling higher levels of sprouted chickpea incorporation. This approach offers a promising solution for applications requiring a well-developed structure, further advancing the industrial potential of sprouted grains in sustainable and innovative baked goods. Overall, the main outcomes of this PhD thesis provide new insights on the valorization of less common grains in baked goods, through the set-up of the sprouting process.
Settore AGR/15 - Scienze e Tecnologie Alimentari, Settore AGRI-07/A - Scienze e tecnologie alimentari
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