Collagen peptide fractions from tilapia (Oreochromis aureus Steindachner, 1864) scales: Chemical characterization and biological activity
Karen L. Hernández-Ruiz, Jaime López‐Cervántes, Dalia I. Sánchez‐Machado, Olga N. Campas‐Baypoli, Angie Araí Quintero-Guerrero, Maria de Lourdes Grijalva-Delgado, Andrés Francisco Chávez-Almanza
Abstract
This research project was focused on the isolation of compounds from natural sources and their chemical characterization and biological activity were evaluated. Tilapia is a popular fish and large amounts of byproducts are generated from its industrialization. Considering the abundance of this waste and its low value-added uses, collagen can be recovered at low costs. Collagen has low toxicity, good compatibility, biodegradability, and functional properties in foods. Thus, industrial byproducts could be considered as a valuable source for the recovery of collagen and the isolation of collagen peptides. In this work, fish scales were used to isolate hydrolyzed collagen using papain . Two fractions of collagen peptides were separated: F1 (5–10 kDa peptides) and F2 (<5 kDa peptides) through molecular weight cut-offs to evaluate the biological activity improvement. Characteristic functional groups of native collagen were identified by Fourier transform infrared (FTIR) spectroscopy. The most abundant total amino acids were glycine, hydroxyproline , and proline , while the predominant free amino acids were glycine, tyrosine , and proline . In the evaluation of antioxidant activity and capacity, F1 presented the highest antioxidant content and required the least amount of sample to inhibit 50% of the ABTS and DPPH radicals (IC 50 ). An antimicrobial effect against Escherichia coli of clinical origin was observed, although the fraction had no effect on Staphylococcus aureus . Therefore, hydrolyzed collagen is a valuable resource for the production of peptides with bioactive properties to be used in various applications.