Bioactivity and Functionality of Gelatin Hydrolysates from the Skin of Oneknife Unicornfish (Naso thynnoides)

Lipid-Induced Oxidative Modifications Decrease the Bioactivities of Collagen Hydrolysates from Fish Skin: The Underlying Mechanism Based on the Proteomic Strategy

Collagen peptides exhibit various bioactivities, including antioxidation and ACE inhibition. However, the bioactivities of collagen peptides decrease gradually due to oxidation deterioration during storage, and this degradation of bioactive peptides is rarely studied. In this study, the oxidative levels and the bioactivities of collagen peptides were investigated during an oxidative-induced storage accelerated by lipids. The results suggested that the oxidation of collagen peptides was divided into three stages. At the early stage, the carbonyl content of collagen peptides increased rapidly (from 2.32 to 3.72 μmol/g peptide), showing a close correlation with their bioactivities (for antioxidation, r = -0.947; for ACE inhibition, r = -0.911). The oxidation level in the middle stage continued but was stable, and the bioactivities decreased. At the later stage, the Schiff base and dityrosine content increased significantly and showed a strong correlation with the bioactivities (antioxidation, r = -0.820, -0.801; ACE inhibition, r = -0.779, -0.865). The amino acid and proteomic analyses showed that Met, Lys, and Arg were susceptible to oxidation and revealed their oxidative modification types. This study provided an insight into the dynamic oxidative modifications of collagen peptides, which were shown to correlate well with the change in bioactivities.

Unconventional microbial proteases as promising tools for the production of bioactive protein hydrolysates

Enzymatic hydrolysis is the most prominent strategy to release bioactive peptides from different food proteins and protein-rich by-products. Unconventional microbial proteases (UMPs) have gaining increased attention for such purposes, particularly from the 2010s. In this review, we present and discuss aspects related to UMPs production, and their use to obtain bioactive protein hydrolysates. Antioxidant and anti-hypertensive potentials, commonly evaluated through in vitro testing, are mainly reported. The in vivo bioactivities of protein hydrolysates and peptides produced through UMPs action are highlighted. In addition to bioactivities, enzymatic hydrolysis acts by modulating the functional properties of proteins for potential food uses. The compiled literature indicates that UMPs are promising biocatalysts to generate bioactive protein hydrolysates, adding up to commercially available enzymes. From the recent interest on this topic, continuous and in-depth research is needed to advance toward the applicability and commercial utility of both UMPs and obtained hydrolysates.

Assessment of the biotechnological activity of wheat hydrolysates prepared with the Biarum bovei extract

In this study, Biarum bovei extract was used to produce bioactive peptides from wheat gluten protein and the biological and functional properties of the hydrolysates were determinated. The results showed that Biarum bovei extract has its highest protease activity (7.3 U/mg protein) at 45 °C and pH 5. Based on electrophoresis analysis, the molecular weight of hydrolysate was < 10 kDa. F1 fraction had the highest antioxidant activity in DPPH (65.85 ± 2.64 µmol TE/g)) and ABTS radical scavenging assays (295.81 µmol TE/g). F2 fraction with 86.3 ± 0.48 had the ability to inhibit the ACE enzyme. The F3 and F1 fractions had statistically the highest inhibition rate (49.37 ± 0.12%. and 79.19 ± 1.13%) in alpha-glucosidase and alpha amylase, respectively. The F1, F2 fractions hydrolysate had an inhibitory effect on Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. Functional properties of hydrolysates with increasing molecular weight, increased significantly. The presence of high levels (p ≤ 0.05) of amino acids with hydroxyl groups, hydrophobic and positive charged in fractions had critical role on biological and technological activity. These findings confirmed the efficiency of gluten hydrolysates with low molecular weight (F1 < 3 kDa) on biofunctionality such as scavenging radical activity, ACE inhibitory, antidiabetic and antibacterial activity could be beneficial from health and technological perspectives.

Bioactive Peptide Fractions from Collagen Hydrolysate of Common Carp Fish Byproduct: Antioxidant and Functional Properties

Collagen isolated from byproducts of common carp was hydrolyzed with alcalase enzyme to obtain peptide fractions. The resulting >30 kDa (PF1), 10−30 kDa (PF2), 3−10 kDa (PF3) and <1 kDa (PF4) fractions were studied for their antioxidant and functional properties. All peptide fractions illustrated antioxidant activity at different concentrations (1, 5, and 10 mg/mL). Although PF4 indicated the highest DPPH radical-scavenging activity (87%) at a concentration of 1 mg/mL, the highest reducing power (0.34) and hydroxyl radical scavenging activity (95.4%) were also observed in PF4 at a concentration of 10 mg/mL. The solubility of the peptide fractions was influenced by pH. The lowest solubility of the peptide fractions was observed at pH 4. The highest emulsifying activity index (EAI) was observed for PF4 (121.1 m2/g), followed by PF3 (99.6 m2/g), PF2 (89.5 m2/g) and PF1 (78.2 m2/g). In contrast to what has been found in the case of EAI, the emulsion stability of the peptide fractions decreased at lower molecular weight, which ranged from 24.4 to 31.6 min. Furthermore, it was revealed that PF1 had the highest foam capacity (87.4%) and foam stability (28.4 min), followed by PF2 and PF3. Overall, the findings suggest that peptide fractions isolated from byproducts of common carp are a promising source of natural antioxidants for application in functional food and pharmaceutical products.

Valorization of fish byproducts: Sources to end-product applications of bioactive protein hydrolysate

Fish processing industries result in an ample number of protein-rich byproducts, which have been used to produce protein hydrolysate (PH) for human consumption. Chemical, microbial, and enzymatic hydrolysis processes have been implemented for the production of fish PH (FPH) from diverse types of fish processing byproducts. FPH has been reported to possess bioactive active peptides known to exhibit various biological activities such as antioxidant, antimicrobial, angiotensin-I converting enzyme inhibition, calcium-binding ability, dipeptidyl peptidase-IV inhibition, immunomodulation, and antiproliferative activity, which are discussed comprehensively in this review. Appropriate conditions for the hydrolysis process (e.g., type and concentration of enzymes, time, and temperature) play an important role in achieving the desired level of hydrolysis, thus affecting the functional and bioactive properties and stability of FPH. This review provides an in-depth and comprehensive discussion on the sources, process parameters, purification as well as functional and bioactive properties of FPHs. The most recent research findings on the impact of production parameters, bitterness of peptide, storage, and food processing conditions on functional properties and stability of FPH were also reported. More importantly, the recent studies on biological activities of FPH and in vivo health benefits were discussed with the possible mechanism of action. Furthermore, FPH-polyphenol conjugate, encapsulation, and digestive stability of FPH were discussed in terms of their potential to be utilized as a nutraceutical ingredient. Last but not the least, various industrial applications of FPH and the fate of FPH in terms of limitations, hurdles, future research directions, and challenges have been addressed.

Elucidating the Biological Activity of Fish-Derived Collagen and Gelatine Hydrolysates using Animal Cell Culture - A Review

A large percentage of a fish's weight is generally discarded during fish processing. Reducing the waste products of marine origin is a subject of great interest within the scientific community. Pelagic byproducts, such as the structural protein collagen, which can be generated during the processing of fish, have been proposed as an alternative to terrestrial, mammalian sources due to advantages including high availability and low risk of zoonotic disease transmission. Gelatine has multiple possible applications, ranging from nutraceutical applications to cosmetics and has the advantage of being generally regarded as safe. In this multidisciplinary review, the chemistry of gelatine and its parent protein collagen, the chemical reactions to generate their hydrolysates, and studies on their biological activities using animal cell culture are discussed.