Influence of Commercial Protease and Drying Process on Antioxidant and Physicochemical Properties of Chicken Breast Protein Hydrolysates

Anticancer and Antioxidant Effects of Bioactive Peptides from Black Soldier Fly Larvae (Hermetia illucens)

BACKGROUND

Protein hydrolysates from insects are recognized for their biological activities. Black soldier fly larvae (BSFL) have drawn attention due to their antioxidant protein hydrolysates. However, research on bioactive peptides derived from these hydrolysates, particularly their cancer chemopreventive potential, remains limited. This study aims to evaluate the antioxidant, anti-inflammatory, antimutagenic, and anticancer activities of BSFL-derived bioactive peptides and explore the molecular mechanisms.

METHODS

Alkali-soluble BSFL protein (ASBP) was extracted and hydrolyzed using Alcalase and bromelain under optimized conditions. Antioxidant activity was assessed via FRAP, ABTS, and DPPH assays. The hydrolysate with the highest antioxidant activity was fractionated into molecular weight (MW) groups (>30, 10, and <3 kDa). The bioactivity of fractionated peptides was evaluated through antioxidant, anti-inflammatory (nitric oxide production in RAW 264.7 cells), antimutagenic (Ames test), and anticancer (CCK-8 assay on HCT 116, COLO205, Cw-2, and Caco-2 cells) assays. Mechanistic insights were obtained via microarray and Western blot analyses. Peptides were identified by LC-MS/MS.

RESULTS

The ASBP-Alcalase hydrolysate (ASBP-AH) showed optimal antioxidant activity at 3% (w/w) for 4 h. The ASBP-AH 30 (MW > 30 kDa) fraction exhibited the highest antioxidant capacity. In contrast, the ASBP-AH3 (MW < 3 kDa) fraction exhibited significant antimutagenic effects, reduced nitric oxide production, and decreased COLO205 cell viability. Treatment with ASBP-AH3 at its LC50 dose modulated the SKP2/p21/cyclin D1 pathways. Mostly peptides from ASBP-AH3 were composed of hydrophobic and charged amino acids.

CONCLUSIONS

BSFL-derived bioactive peptides exhibit potential as multifunctional agents for cancer chemoprevention. In vivo studies are required to explore their clinical applications.

Enhancing storage stability of pea peptides through encapsulation in maltodextrin and gum tragacanth via monitoring scavenge ability to free radicals

Pea peptides can lead to degradation through oxidation, deamidation, hydrolysis, or cyclization during production, processing, and storage, which in turn limit their broader application. To stabilize pea peptides, this study employed spray drying technology to create a pea peptide micro-encapsule using maltodextrin, gum tragacanth, and pea peptides. Four key factors, including polysaccharide ratio, glycopeptide ratio, solid-liquid ratio, and inlet temperature, were optimized to enhance the antioxidant properties of the pea peptide micro-encapsule. The results indicated that the utilization of maltodextrin and gum tragacanth significantly improves the storage stability and antioxidant activity of pea peptides. Moreover, optimal storage stability for pea peptides was achieved with a polysaccharide ratio of 9:1, a glycopeptide ratio of 10:1, a solid-liquid ratio of 4:40, and an inlet temperature of 180 °C. After 60 days of storage, the encapsulated pea peptides maintained 70.22 %, 25.19 %, and 40.32 % for scavenging abilities to hydroxyl radical, superoxide anion, and ABTS radical, respectively. In contrast, the unencapsulated pea peptides showed a decline to 47.02 %, 0 %, and 24.46 % in the same antioxidant activities after storage. These findings underscore the potential of spray drying technology to enhance the functional properties of pea peptides for various applications.

Evaluating the capability of soybean peptides as calcium ion carriers: a study through sequence analysis and molecular dynamics simulations

Calcium homeostasis imbalance in the body can lead to a variety of chronic diseases. Supplement efficiency is essential. Peptide calcium chelate, a fourth-generation calcium supplement, offers easy absorption and minimal side effects. Its effectiveness relies on peptide's calcium binding capacity. However, research on amino acid sequences in peptides with high calcium binding capacity (HCBC) is limited, affecting the efficient identification of such peptides. This study used soybean peptides (SP), separated and purified by gel chromatography, to obtain HCBC peptide (137.45 μg mg-1) and normal peptide (≤95.78 μg mg-1). Mass spectrometry identified the sequences of these peptides, and an analysis of the positional distribution of characteristic amino acids followed. Two HCBC peptides with sequences GGDLVS (271.55 μg mg-1) and YEGVIL (272.54 μg mg-1) were discovered. Molecular dynamics showed that when either aspartic acid is located near the N-terminal's middle, or glutamic acid is near the end, or in cases of continuous Asp or Glu, the binding speed, probability, and strength between the peptide and calcium ions are superior compared to those at other locations. The study's goal was to clarify how the positions of characteristic amino acids in peptides affect calcium binding, aiding in developing peptide calcium chelates as a novel calcium supplement.

Isolation and Identification of Antioxidant Peptides Derived from Cricket (Gryllus bimaculatus) Protein Fractions

Crickets contain high protein content that can be used to improve nutrition but are less exploited. This study was conducted to isolate different Cricket Protein Fractions including albumin, globulin, glutelin, and prolamin. All fractions were characterized and hydrolyzed by commercial enzymes. The results showed that the glutelin fractions had the highest extraction yields with 53.9 ± 2.12% (p < 0.05). Moreover, glutelin hydrolysate fraction prepared by Alcalase with a 16.35 ±0.29% hydrolysis degree was selected for further purification because of their high antioxidant activities, including ABTS radical-scavenging activity (0.44-0.55 µmol Trolox eq./g) and metal chelating activity (1721.99-1751.71 µmol EDTA eq./g). Two active fractions, GA-1 (<3 kDa) and GA-2 (<3 kDa), were collected from the consecutive purification of glutelin hydrolysates, which included processes such as membrane ultrafiltration and gel filtration. The fractions were analyzed by LC-MS/MS to obtain 10 peptides with 3-13 amino acids identified as TEAPLNPK, EVGA, KLL, TGNLPGAAHPLLL, AHLLT, LSPLYE, AGVL, VAAV, VAGL, and QLL with a molecular weight range of 359.23-721.37 Da in the two fractions. The amino acid sequence shows a prevalence of hydrophobic amino acids (50-100%) such as valine and leucine in the peptide chains, accounting for its high antioxidant activity. In conclusion, cricket glutelin hydrolysate prepared by Alcalase can serve as an alternative source of potent edible bioactive peptides in functional food products.

Physicochemical characteristics and antioxidant stability of spray-dried soy peptide fractions

The direct addition of health-promoting peptides to food products is limited due to their physicochemical instability and bitter taste as well as their bio-functionality may be influenced by M_W. In this study, SPI hydrolysate (SPIH) was Alcalase-prepared, size-fractionated (<10, 10-30, and 30-100 kD), and the amino acid composition of peptide fractions determined. The physicochemical properties, morphology, and antioxidant stability of the fractions were also investigated after spray-drying encapsulation in maltodextrin-WPC carrier. The two low M_W peptide fractions (especially, PF < 10) were more active than intact SPI, SPIH, and high M_W peptide fraction in scavenging free radicals and chelating transition metal ions. As compared to the particles containing SPIH, those containing the smallest peptide fraction (PF < 10) had higher solubility and hygroscopicity, lower production yield and wettability, and more wrinkles, indentations and surface roughness. The highest antioxidant stability during spray-drying was observed for the two low M_W peptide fractions, which examined by scavenging of free radicals of DPPH (88%), ABTS (97%), OH (93%) and NO (80%), chelating of iron (88%) and copper (87-90%) ions, reducing power (93%), and total antioxidant activity (90%). This finding reflects more structural and biological stability of the low M_W fractions to shear stress and dehydration during spray-drying, as compared with SPIH. The spray-drying encapsulated soy peptide fractions may be used as nutraceuticals for the development of functional foods.

Effects of Spray Drying and Freeze Drying on Physicochemical Properties, Antioxidant and ACE Inhibitory Activities of Bighead Carp (Aristichthys nobilis) Skin Hydrolysates

The physicochemical, structural properties, antioxidant, and angiotensin I-converting enzyme (ACE) inhibitory activities of fish skin protein hydrolysate (SPH) that were freeze-dried (SPH-FD) and spray-dried (SPH-SD) were investigated. SPH-SD showed abundant volatile compounds, higher DPPH radical scavenging activity and ferrous iron chelating activity than SPH-FD, while the ABTS radical scavenging activity and ACE inhibitory activity were not influenced by the drying method. Amino acid compositions showed a higher proportion of proline and hydroxyproline residues in SPH-FD. The major molecular weights were both distributed below 1000 Da. SPH-SD had spherical structures, while SPH-FD had glass shard-like structures. The results indicated that the drying method could affect the physicochemical properties of hydrolysates, and SPH-SD showed potential prospects in developing functional fortified foods.