Characterization of Antioxidant Peptides from Thai Traditional Semi-Dried Fermented Catfish

Abstract

Herein, the antioxidant peptides from a Thai traditional semi-dried fermented farmed hybrid catfish (Clarias macrocephalus × Clarias gariepinus) catfish, Pla Duk Ra, were characterized. After extraction and deproteinization, Pla Duk Ra crude peptide extract (CPE) was fractioned using 2 connected Hitrap Sephadex-G25 columns, yielding two significant fractions, F1 with higher browning intensity (A420) and F2. CPE, F1, and F2 had different amino acid profiles, contents, and sequences evaluated by LC-MS/MS, which could be responsible for their antioxidant properties. F2 contained the highest numbers of hydrophobic amino acid (HBA) (47.45%) and aromatic amino acid (27.31%), followed by F1, and CPE. The peptides with 8–24 amino acid residues were detected in CPE and its fractions. In CPE, F1, and F2, there were 69, 68, and 85 peptides with varied HBA content, respectively. ARHSYGMLYCSCPPND (50% HBA), ALRKMGRK (37.5% HBA), and ANWMIPLM (87.5% HBA) were the most prevalent peptides found in CPE, F1, and F2. Overall, F2 was the most effective at inhibiting free radicals (DPPH● and ABTS●+) and reactive oxygen species (hydroxyl radical, singlet oxygen, and hydrogen peroxide), followed by F1 and CPE. The metal chelation of F1 was, however, superior to that of F2 and CPE. For the stability test, the effects of pH, heating temperature, and in vitro digestion on the DPPH● scavenging activity of F2 were investigated. The activity was boosted by lowering the pH and raising the heating temperature. In the gastrointestinal tract model system, however, roughly 50% of DPPH● scavenging activity reduced after digesting.

Optimization and production of protein hydrolysate containing antioxidant activity from tuna cooking juice concentrate by response surface methodology

“…In this study, cysteine, glycine, arginine, histidine, and proline were significantly different (p < 0.05) among fractions. Our results were consistent with the finding of Chaijan et al (2021), who reported that a high content of these AAs enhanced the DPPH and ABTS radical scavenging activity of peptides. However, significant DPPH and ABTS radical scavenging activities were observed from different fractions.…”

“…Based on our results, it is likely that not only the AA contents affected the free radical scavenging activity of the VD fraction. Other factors, such as AA sequences, the stereoselectivity of radicals, and the stoichiometry between radicals and antioxidants, may be associated with antioxidant activities (Borawska et al, 2015;Chaijan et al, 2021). In this study, the sum of AAA (tyrosine and phenylalanine) and PCAA (histidine, arginine, and lysine) content was the highest in VD-1, followed by respectively (28.76,28.54,and 24.33 g/100 g protein, respectively).…”

Optimization of Fermentation Process of Wheat Germ Protein by Aspergillus niger and Analysis of Antioxidant Activity of Peptide

“…The enzyme system produced by Aspergillus niger enzymatically cleaves wheat germ proteins to amino-acid-residue-exposed polypeptides, which are more favorable for binding to the moiety and acting activity. The antioxidant peptides extracted from traditionally semi-dried fermented fish in Thailand exhibit significant efficacy in suppressing free radicals and reactive oxygen species (ROS) [43]. This observed effect may be attributed to the presence of hydrophobic and aromatic amino acids within these peptides.…”

Transforming the fermented fish landscape: Microbiota enable novel, safe, flavorful, and healthy products for modern consumers

“…These peptides are further broken down by the proteases secreted from microorganisms to form small peptides, which are subsequently converted to free amino acids by the peptidases released upon cell lysis (Candogan & Acton, 2004; Patcharin et al., 2006). Among the peptides generated during fish fermentation, some exhibit important health‐promoting properties such as antibacterial effect (Mirzapour‐Kouhdasht et al., 2021), antioxidant activity (Chaijan et al., 2021) and antihypertensive function (Itou et al., 2007; Ryan et al., 2011). It is of high interest to study the relationships among the microorganisms, enzymes, and their metabolites or enzymatic reaction products for tailoring the fish fermentation process to yield target compounds.…”