Integration of ancient wheat flours and almond skin by-products on the technological properties of bread samples

Against the burden of the global food waste crisis and the need for healthier and more sustainable diets, growing attention has been directed to neglected and underutilized species and the reuse of agro-industrial by-products. The interaction between almond skin, as a nutrient resource, and ancient wheat varieties remains underexplored. This study aims to evaluate bread samples formulated with almond skin (AS) powder at two levels (4 and 8 g/100 g) with modern (Bolero) and ancient (Autonomia B, Bianchetta, Frassineto, and Risciola) wheat flours, and to assess dough rheology, bread quality, texture, and microstructure. For enriched samples, farinograph parameters showed increased water absorption alongside reduced dough development time and stability. A clear variety-dependent response to AS enrichment was observed. The varieties Autonomia B, Bianchetta, and Frassineto at 8% AS enrichment exhibited significantly greater loaf heights than the control, indicating improved baking performance. Microstructural analysis revealed some changes in bread crumb, including reduced porosity and structural thickness in enriched samples. Notably, porosity decreased in Bolero AS8% (49.66%) and Bianchetta AS8% (58.81%), while Autonomia B AS8% showed the highest value (65.32%), consistent with its lower hardness and chewiness. Staling behavior further highlighted that after 48 h, although all samples exhibited moisture redistribution and crumb firming, more pronounced changes were observed in the ancient wheat control breads, suggesting a potential role of AS in modulating bread staling. By valorizing an agro-industrial by-product and promoting the use of diverse wheat varieties, this study provides new evidence of the variety-dependent response to AS enrichment and contributes to biodiversity conservation and the development of more sustainable food systems.