Sustainable nutritional improvement of bread enriched with sprouted cowpea flour

Pulses are a worldwide component of human diet and play a crucial role in meeting protein requirement particularly in developing countries. Although pulses offer significant health benefits, they also contain antinutritional compounds like phytates, enzyme inhibitors, and gut-fermenting oligosaccharides. Sprouting has emerged as a sustainable, and cost-effective method to enhance nutrient availability and decrease the levels of these antinutritional components. Among legumes, cowpea (Vigna unguiculata) is an important crop, ideal for developing innovative products. This study focused on investigating the impact of short-term sprouting (48 and 72 hours) on the biomolecular features, antioxidant, and antinutritional factors in beans. After 72 hours of sprouting, bean flour showed a significant reduction in the content of antinutritional components along with an increase in protein hydrolysis. Sprouted cowpea flour was incorporated into bread formulation at a 25% substitution level for wheat flour, with unsprouted bean flour serving as a control. Comprehensive analysis included protein profile and quantification of anti-nutritional factors. Additionally, bread samples were subjected to in vitro static digestion in accordance with the INFOGEST protocol, with protein hydrolysis assessed at the end of the gastric phase, and at both midpoint and the endpoint of the intestinal phase. It seems that cowpea proteins were degraded into small peptides following duodenal digestion in all bread samples. Moreover, from a nutritional point of view, bread enriched with either sprouted and unsprouted bean flour showed a reduction in total accessible starch, rapidly digestible, and total digestible starch. However, an increase in resistant starch was observed in sample containing sprouted bean flour. In addition, bread made with sprouted bean flour, exhibited the lowest level of trypsin inhibitors, phytates, and oligosaccharides. Acknowledgments: Partially supported by National Recovery and Resilience Plan (NRRP), Mission4 Component 2 Investment 1.3 -Call for tender No. 341 of 15/03/2022 of Italian Ministry of University and Research funded by the European Union–NextGenerationEU, in the frame of the project: Research and innovation network on food and nutrition Sustainability, Safety and Security (ON Foods).