The economic system has traditionally operated according to the linear model, which predicts that a product will reach its end of life, moving towards production, consumption, and finally, disposal. However, this model has proven unsustainable in the agri-food sector, leading to enormous food losses and waste and a cascade of adverse environmental, economic, and social effects. However, agri-food by-products are deemed as possible sources of bioactive molecules with beneficial health properties like phenolic compounds or dietary fiber. Indeed, polyphenols are crucial in preventing non-communicable diseases, whereas dietary fiber helps prevent obesity, reduce blood cholesterol levels, and improve intestinal stool transit. For this reason, an optimal and reasonable scope for the food by-products could be their incorporation in different food matrices, thus becoming functional food ingredients to improve economic systems sustainability and foodstuff's nutritional profile. Therefore, the main goal of the current PhD project was to upcycle different agrofood byproducts (AFBYs) (namely, grape, red chicory, and apple by-products) from the agro-industry and study their incorporation into bakery or pasta formulations and study how those AFBYs impact the final product's nutritional, physicalchemical, textural, rheological, and sensory properties. In addition, I characterized phenolic compounds by HPLC-MS/MS method of some of the AFBYs and studied their fate by performing an in vitro digestion. In particular, I focused on different agrifood-derived by-products added to various food matrices as reported below: - Grape pomace from vinification processes and Breadsticks; - Grape pomace from the distillery process and Muffins; - Amarone wine lees as a fat substitute in Muffins; - Red chicory by-product in durum wheat semolina Pasta; - Red chicory by-product in Bread; - Apple cider by-product (apple pomace) in Cracker