Alejandra Colón-Sandoval, Laura Aracely Contreras‐Angulo, Luis Ángel Cabanillas-Bojórquez, Erick Paul Gutiérrez‐Grijalva, Josefina León‐Félix, Nayely Leyva‐López, Leticia X. López‐Martínez, Miriam D. García-Cebreros, J. Basilio Heredia
Peptides are short amino acid chains that can be released from proteins through hydrolysis or fermentation, exhibiting various biological activities, including antioxidant, antihypertensive, anti-inflammatory, and anticancer effects. Generally, these compounds are extracted from food products. However, to maximize resource utilization under the premise of sustainability in favor of a circular economy, there is an interesting approach to obtaining peptides from sub-utilized parts and non-food products of food production and processing, based on the grade at which they can be valued. These by-products may contain large quantities of protein that can be utilized. Although some may have a low protein content, they stand out for the quality and proportion of their amino acids, which provide properties with functional applications. This revision approaches some of the most recent reports on isolated peptides from residues, by-products, or underutilized parts from plant, animal, or sea origin; the conventional methods and alternative technologies to isolate them from the origin matrixes; the methods to purify and identify them, the biological activities they perform, as well as a brief description of the application fields of these compounds and the challenges that their application faces in biomedicine and the food industry.