Gelatin and Antioxidant Peptides from Gelatin Hydrolysate of Skipjack Tuna (Katsuwonus pelamis) Scales: Preparation, Identification and Activity Evaluation

Abstract

For full use of fish by-products, scale gelatin (TG) and antioxidant peptides (APs) of skipjack tuna (Katsuwonus pelamis) were prepared, and their properties were characterized using an amino acid analyzer, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectroscopy (FTIR), electrospray ionization mass spectrometers (ESI-MS), and radical scavenging assays. The results indicate that TG with a yield of 3.46 ± 0.27% contained Gly (327.9 ± 5.2 residues/1000 residues) as the major amino acid and its imino acid content was 196.1 residues/1000 residues. The structure of TG was more unstable than that of type I collagen from scales of skipjack tuna (TC) and TG was more suitable for preparation of hydrolysate by protease than mammalian gelatins. Therefore, TG was separately hydrolyzed under five proteases (pepsin, papain, trypsin, neutrase, and alcalase) and ten APs (TGP1–TGP10) were isolated from the alcalase-hydrolysate. Among them, TGP5, TGP7, and TGP9 with high antioxidant activity were identified as His-Gly-Pro-Hyp-Gly-Glu (TGP5), Asp-Gly-Pro-Lys-Gly-His (TGP7) and Met-Leu-Gly-Pro-Phe-Gly-Pro-Ser (TGP9), respectively. Furthermore, TGP5, TGP7, and TGP9 exhibited a high radical scavenging capability on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (EC50 values of 1.34, 0.54, and 0.67 mg/mL, respectively), hydroxyl radical (EC50 values of 1.03, 0.41, and 0.74 mg/mL, respectively), and superoxide anion radical (EC50 values of 1.19, 0.71, and 1.59 mg/mL, respectively). These results suggest that three APs (TGP5, TGP7, and TGP9), especially TGP7, have a strong antioxidant activity and could act as potential antioxidant ingredients applied in functional products.

Characterization and Antioxidant Activity of Collagen, Gelatin, and the Derived Peptides from Yellowfin Tuna (Thunnus albacares) Skin

“…However, the scavenging activity of nearly 100% was reported for the peptide from horse milk at 1 µg/mL [52]. On the other hand, the gelatin hydrolysate from skipjack scale showed the scavenging activity in the concentration range of 0.1-5.0 mg/mL [8]. The lower the molecular weight, the stronger the scavenging activity tends to become.…”

“…In addition, there are associated health concerns such as bovine spongiform encephalopathy (BSE), transmissible spongiform encephalopathy (TSE), and foot and mouth disease (FMD). Therefore, fishery by-products such as skin, bone, scale, and swim bladder could be alternatives for collagen and gelatin production [8][9][10]. The yellowfin tuna skin waste could be an alternative raw material for making safe and preferable collagen and gelatin.…”

“…Recently, the bioactive peptide with antioxidant properties from enzymatically hydrolyzed proteins is a topic of great interest in the pharmaceutical and food processing industries [14]. Previous researchers reported that Alcalase showed the most effective among five kinds of proteases to hydrolyze gelatin from skipjack Katsuwonus pelamis scales, resulting in strong antioxidant activities of the peptides obtained [8]. Antioxidant supplementation can maintain normal skin cell function by preventing free radical accumulation [15].…”

Antioxidant Peptides from the Protein Hydrolysate of Monkfish (Lophius litulon) Muscle: Purification, Identification, and Cytoprotective Function on HepG2 Cells Damage by H2O2

“…ROS are generated by different physiological and biochemical oxidative processes in the organisms and associated with numerous physiological and pathophysiological processes [41,42]. At high levels, ROS damage some key biological macromolecules and play a major role in the pathogenesis of various human diseases [43,44].…”

Hypolipidemic Activities of Two Pentapeptides (VIAPW and IRWWW) from Miiuy Croaker (Miichthys miiuy) Muscle on Lipid Accumulation in HepG2 Cells through Regulation of AMPK Pathway

“…To date, active ingredients from natural resources including polysaccharides, quinones, alkaloids, flavonoids, steroidal saponins, and proteins and peptides, have been identified as potential hypolipidemic agents because they could accelerate the catabolism of exogenous lipid, suppressing the biosynthesis of endogenous lipids and inhibiting lipid absorption and peroxidation [4,[8][9][10]. Among them, food-derived peptides attract extensive attention because they have physiological functions beyond their high nutritional values and can act as drugs and functional products [11][12][13][14]. Fan et al (2018) purified and identified four peptides including NPVWKRK, NALKCCHSCPA, CANPHELPNK, and LNNPSVCDCDCMMKAAR from protein hydrolysate of Spirulina platensis.…”