Antioxidant Activity of Proteins and Peptides

Optimization of ultrasound-assisted enzymatic hydrolysis Zophobas morio protein and its protective effects against H2O2-induced oxidative stress in RAW264.7 cells

Zophobas morio protein (ZMP) is a promising protein resource with notable biological properties, and its hydrolysis could unlock enhanced bioactivities. This study investigated ultrasound-assisted enzymatic hydrolysis (UAEH) of ZMP using different enzymes (Alcalase, Neutrase, and Protamex) to determine its effect on the degree of hydrolysis (DH) compared to enzymatic hydrolysis (EH). UAEH showed greater hydrolysis efficiency than EH, with Alcalase exhibiting the highest DH. Response surface methodology (RSM) was applied to optimize UAEH conditions for Zophobas morio protein hydrolysate (ZMPH). Optimal conditions for producing ZMPH with the maximum DH were a substrate concentration of 3.52 % (w/v), enzyme to substrate ratio of 7.64 % (v/v), and pH of 8.35. Under the optimal condition, the maximum DH was 25.03 %. In addition, significant structural changes in the optimized ZMPH compared to ZMP were identified, showing decreased α-helix and β-sheet content, with increased β-turn and unordered coil. Moreover, the optimized ZMPH demonstrated significantly improved ABTS antioxidant activity and attenuated H2O2-induced cell death in RAW264.7 cells compared to ZMP, which was attributed to better mitigation of ROS production. These findings provide an effective enzymatic hydrolysis method for producing ZMPH with significant antioxidant activity, demonstrating the potential of ultrasound-assisted hydrolysis in enhancing the bioactivity of insect proteins.

Design and advances in antioxidant hydrogels for ROS-induced oxidative disease

Reactive oxygen species (ROS) play a crucial role in human physiological processes, but oxidative stress caused by excessive ROS may lead to a variety of acute and chronic diseases. Despite the development of various strategies and biomaterials, an efficiently and broadly applied method for treatment of ROS-induced oxidative disease remains a bottleneck. Aiming to improve the local oxidative stress environment, numerous bioactive hydrogels with antioxidant properties have emerged and are proven to quickly and continuously eliminate excessive ROS. To deeply understand the design principles and applications of antioxidant hydrogels is highly beneficial for designing antioxidant hydrogels for treatment of oxidative disease. This review provides a detailed summary of recent advances in design and applications of antioxidant hydrogels for various ROS-induced oxidative diseases. In this review, the kinds of antioxidant components in antioxidant hydrogels are outlined in detail. Additionally, the crosslinking methods and the biomedical applications of antioxidant hydrogels are widely summarized and discussed, especially focusing on their usage in different types of diseases and the attention given to the treatment of diseases such as skin wounds, myocardial infarction, and osteoarthritis. Finally, the future development direction of antioxidant hydrogel is further proposed. STATEMENT OF SIGNIFICANCE: Oxidative stress is a pivotal biochemical process that plays a critical role in cellular homeostasis. Excessive cellular oxidative stress triggers an inflammatory response, which is implicated in a spectrum of associated diseases. Given the critical need for managing oxidative stress, antioxidant therapies have become a vital focus in medical research. Hydrogels have garnered substantial interest among biomaterial scientists due to their hydrophilic nature and biocompatibility. The review delves into the realm of antioxidant hydrogels, encompassing the classification of antioxidant components, the synthesis and fabrication of hydrogels, and a comprehensive overview of the biological applications and challenges of these antioxidant hydrogels. Aiming to provide new perspectives for researchers in developing cutting-edge therapeutic approaches that leverage antioxidant hydrogels.

Effect of reduced flaxseed cyclic peptide [1-9-NαC]-linusorb B2 (CLB) and its oxidized form on the oxidative stability of flaxseed oil

This study aimed to explore the antioxidant capacity and mechanism of cyclic peptide [1-9-NαC]-linusorb B2 (CLB) and its oxidized form ([1-9-NαC],[1-MetO]-linusorb B2 (CLC),[1-9-NαC],[1-MetO2]-linusorb B2 (CLK)) in flaxseed oil (FSO). The results showed that CLB delayed the oxidation of FSO (containing Cu2+) in the initial stage of accelerated oxidation, whereas CLK accelerated the oxidation, leading to an increase of 25 % in AV and 33 % in POV (P < 0.05). In molecular docking, the binding ability of cyclic peptides to metal ions and intermediate oxidative products such as aldehydes tends to decrease when CLB oxidized to CLC, then CLK. CLK had the poorest binding capacity with the most serious oxidation on FSO. In conclusion, the antioxidant capacities of CLB and its oxidized form were contributed by their reducing ability as well as their binding ability to metal ions and intermediate oxidative products of fatty acids.

Antioxidant potential of peptides derived from chia seeds (Salvia hispanica L.) as natural preservatives

The challenge of preserving food quality without relying on harmful antioxidants requires the exploration of natural alternatives, such as chia-derived peptides (YACLKVK, KLKKNL, KLLKKYL, and KKLLKI). The antioxidant properties and stability to processing were evaluated using DPPH and ABTS, iron-reducing, ORAC, and copper chelating assays. The effects of autoclaving, heat treatment with glucose, and ultrasound on the antioxidant activity of the top-performing peptide were examined. YACLKVK displayed the highest antioxidant response with 87.25 ± 2.47 %, 93.65 ± 0.79 %, 0.418 ± 0.018 abs, 44.06 ± 0.78 μM TE/mL, and 86.49 ± 0.12 % in the DPPH, ABTS, iron-reducing capacity, ORAC, and copper chelating assays at 800 μg/mL (DPPH) and 1000 μg/mL, respectively. Autoclaving, heat, and ultrasound treatments reduced YACLKVK's DPPH scavenging to 63.09 ± 0.44 % and 74.15 ± 0.27 % and its Cu chelating capacity to 58.98 ± 1.28 %. YACLKVK retained over 50 % of its antioxidant capacity post-processing. These findings suggest its application as a potent natural antioxidant in food systems, particularly in processed foods where oxidation affects shelf life and quality. Incorporating YACLKVK could enhance food preservation, aligning with consumer preferences for natural-origin ingredients. Studies on commercial scalability, safety, and regulatory compliance will be essential for its widespread adoption in the food industry.

Characterizing the mono- and triacylglycerol lipase (MAGL and TAGL) genes from pearl millet (Pennisetum glaucum L.) and elucidating their dynamics with biochemical traits linked with rancidity

MAIN CONCLUSION

We cloned two variants of lipase gene-MAGL and TAGL from pearl millet. Lipase showed negative correlation with antioxidants and total phenolics. FAA can be used as marker for rancidity. Pearl millet is considered as "Nutri-cereal" due to its rich nutrient profile. Low keeping quality of the flour due to rancidity is one of the major problems in pearl millet. Lipases are a group of enzymes that produces free fatty acids that ultimately leads to rancidity. Very few lipases have been identified and characterized from pearl millet. Here, we have identified 2039 transcripts of lipases from pooled samples (leaf, stem and developing grains) of pearl millet using de novo transcriptomic approach and predicted 05 full length lipase variants. Further, we cloned 02 lipase genes-monoacylglycerol lipase (MAGL, acc. no. MZ590564) and triacylglycerol lipase (TAGL, acc. no. MZ590565) of 1.5 kb each from pearl millet cv. Pusa-1201. Conserved domain search analysis showed the presence of catalytic triad [GXSXG] near the active site which is signature domain of lipase family of proteins. MAGL showed maximum expression in PC-701 and TAGL in Pusa-1201 during mealy-ripe growth stage of endospermic tissue. Abundance of transcripts of both the lipases was observed in the harvested grains of PC-701. We observed negative correlation between the lipase activity and accumulation of antioxidants like total phenolic content (TPC), tannin, and total antioxidant potential (TAP). Free amino acid and reducing sugar were observed as potential markers for accessing the intensity/extent of rancidity in pearl millet flour. Thus, there is need to explore and characterize the lipase variants to connect the missing dots in rancidity pathway and to use it in genome editing using the CRISPR/Cas9 approach for the development of pearl millet lines free of off-odor and flour rancidity.

The oxidative stability of sunflower oleosomes depends on co-extracted phenolics and storage proteins

Unsaturated triacylglycerols (TAGs) are highly oxidatively stable when extracted as part of the natural lipid droplets (oleosomes) from seeds. This study investigates whether this protection is inherent to oleosomes or derives from phenolics (PHE) and storage proteins (PRO), which are commonly co-extracted with oleosomes. Oleosome extracts with low (PHE <0.7 mmol/kg TAGs, PRO <4 wt% on DM) or high (PHE >10 mmol/kg TAGs, PRO >9 wt% on DM) amounts of phenolics and storage proteins were obtained from sunflower seeds and then dispersed to create 10 wt% oil-in-water emulsions at pH 3 that were stored at 40 °C for 120 days. No triacylglycerol oxidation occurred in emulsions with high amounts of phenolics, while a high amount of storage proteins reduced the lipid oxidation rate. Our findings evidence that the oxidative stability of triacylglycerols in oleosomes derives primarily from the co-extracted phenolics and storage proteins and not only from the architecture of oleosomes.

Identifying Endogenous Proteins of Perennial Ryegrass (Lolium perenne) with Ex Vivo Antioxidant Activity

Background: During the initial steps of green biorefining aimed at protein recovery, endogenous proteins and enzymes, along with, e.g., phytochemical constituents, are decompartmentalized into a green juice. This creates a highly dynamic environment prone to a plethora of reactions including oxidative protein modification and deterioration. Obtaining a fundamental understanding of the enzymes capable of exerting antioxidant activity ex vivo could help mitigate these reactions for improved product quality. Methods: In this study, we investigated perennial ryegrass (Lolium perenne var. Abosan 1), one of the most widely used turf and forage grasses, as a model system. Using size exclusion chromatography, we fractionated the green juice to investigate in vitro antioxidant properties and coupled this with quantitative bottom-up proteomics, GO-term analysis, and fraction-based enrichment. Results: Our findings revealed that several enzymes, such as superoxide dismutase and peroxiredoxin proteoforms, already known for their involvement in in vivo oxidative protection, are enriched in fractions displaying increased in vitro antioxidant activity, indicating retained activity ex vivo. Moreover, this study provides the most detailed characterization of the L. perenne proteome today and delivers new insights into protein-level partitioning during wet fractionation. Conclusions: Ultimately, this work contributes to a better understanding of the first steps of green biorefining and provides the basis for process optimization.

Enhanced solubility, stability, bioaccessibility, and antioxidant activity of curcumin with hydrolyzed pea protein-based nano-micelles: pH-driven method vs ethanol-induced method

Pea protein nano-micelles gained with partial hydrolysis by a proteolytic enzyme (Protamex) were employed as nanocarriers to encapsulate and stabilize liable and hydrophobic curcumin (CUR) with two various methods (pH-driven method (PDM) and ethanol-induced method (EIM)). Both CUR-loaded pea protein hydrolysates (PPHs) nano-micelles by PDM and EIM exhibited spherical shapes, and uniform particle size distributions. Highest CUR loading amount (3.21 %) was gained with PPHs by PDM. The interaction between PPHs nano-micelles and curcumin was comprehensively examined with optical spectroscopy. These outcomes obviously demonstrated the water solubility, storage stability against UV light and heating, bioaccessibility and in vitro antioxidant activity of CUR can be pronouncedly enhanced with PPHs-based nanocarriers. Interestingly, PPHs-CUR nano-micelles fabricated with PDM have higher loading amount, light stability, and better bioaccessibility as well as antioxidant activity than those by EIM. These results clearly show that PDM may be a better method than EIM and provide useful information in nutraceuticals encapsulation with vegetable proteins-based delivery systems.

Evaluating the Potential of Gamma-Glutamylcysteine and Glutathione as Substitutes for SO2 in White Wine

Sulfur dioxide (SO2) is the most common additive used in winemaking with its antimicrobial and antioxidant properties. However, in recent years, there has been an increasing tendency to reduce the use of excessive SO2 in wine due to its negative effects on human health and organoleptic characteristics. Therefore, the aim of this study was to evaluate the potential use of glutathione (GSH) and its precursor, gamma-glutamyl-cysteine (gGC), which are known as strong antioxidants, for substituting SO2 in white wines. The Turkish indigenous white grape cultivar, Narince (Vitis vinifera), was used to produce white wine. The wines with additions (SO2, gGC, and GSH) and those without (control) were matured for 2 months. As a result, the protective effects of gGC and GSH additions on phenolic compounds, as well as their ability to reduce browning in white wine, were demonstrated. The addition of gGC and GSH enhanced the amount of esters and higher alcohols, improving the wine's aroma. In conclusion, gGC and GSH-particularly gGC-showed great potential as SO2 replacements in wine.

Anti-fatigue effect of an enzymatically derived deer velvet extract through muscle damage recovery and improvement of antioxidant levels

ETHNOPHARMACOLOGICAL RELEVANCE

Deer velvet (DV) has been extensively used in traditional Oriental medicine to treat various diseases. Its pharmacological spectrum encompasses tonicity, longitudinal bone growth of adolescence, blood retention, hemopoiesis facilitation, enhancement of organ function, physical function improvement, and augmentation of physical vitality. Among its myriad effects, DV notably exhibits anti-fatigue properties; however, its specific mode of action is yet to be fully elucidated.

AIM OF THE STUDY

This study was undertaken to investigate the anti-fatigue and exercise performance-enhancing effects of YC-1101(HENKIV®), an enzymatically derived DV extract, in C2C12 cell lines and forced swimming mouse models.

MATERIALS AND METHODS

The effect of YC-1101 on increasing cell growth and lowering lactate dehydrogenase (LDH) activity was assessed in C2C12. The antioxidative effects of YC-1101 and its mechanistic underpinnings were also evaluated in C2C12 cells. Moreover, mice were subjected to an exhaustive swimming test subsequent to 3 weeks of YC-1101 extract administration. Fatigue-associated biochemical parameters, such as LDH activity and lactate, superoxide dismutase, glutathione peroxidase, and malondialdehyde levels, were measured in serum and muscle tissues.

RESULTS

YC-1101 significantly promoted myoblast growth and reduced LDH activity, indicative of a cell-proliferative effect. Notably, free radical scavenging assays and analysis of reactive oxygen species production and antioxidant-related mRNA expression corroborated the significant involvement of YC-1101 in antioxidation, an important mechanism in anti-fatigue processes. Furthermore, animal experiments demonstrated prolonged swimming endurance and inhibition of muscle LDH accumulation in forced swimming mouse models. Serum biochemical analysis further revealed significant modulation of the expression of anti-fatigue-related biomarkers. Various bioactive low-molecular-weight DV peptides were enriched in YC-1101 compared to YHC-BE-2038 (a DV extract without enzymatic digestion). The anti-fatigue effect of YC-1101 was significantly stronger than that of YHC-BE-2038.

CONCLUSIONS

These findings suggest the potential of YC-1101 as a nutraceutical adjunct in ameliorating fatigue, concurrently facilitating muscle damage recovery, and exerting antioxidant effects via the nuclear factor E2-related factor 2-Kelch-like ECH-associated protein-1 pathway. It can be assumed that the complex action of low-molecular-weight DV peptides produced during the enzymatic degradation process was effective, and the further research is needed.

Glycation-mediated pea protein isolate-curcumin conjugates for uniform walnut oil dispersion: enhancing oxidative stability and shelf life

BACKGROUND

Traditional methods for fabricating protein-polyphenol conjugates have not preserved the structural and functional integrity essential for the food industry effectively. This research introduces an advanced encapsulation methodology designed to overcome these limitations, with the potential to enhance the stability of edible oil matrices significantly, leading to improved preservation techniques and extended shelf life.

RESULTS

Glycated pea protein isolate-curcumin conjugates (gPPI-CUR) were developed, demonstrating a marked improvement in the oxidative stability of walnut oil (WO), a proxy for edible oil matrices. Characterized by a Z-average diameter of 158.37 nm and an encapsulation efficiency of 80.94%, these conjugates demonstrated exceptional performance in reducing lipid oxidation and aldehyde formation. Molecular docking analysis confirmed the formation of robust bonds with curcumin, thereby amplifying antioxidant activity. The uniform distribution of gPPI-CUR throughout the walnut oil matrix, as validated by confocal microscopy, ensured sustained bioactivity and mitigated the risk of localized oxidation. Electron spin resonance spectroscopy corroborated the superior antioxidant properties of the conjugates, which translated into a substantial 19-day increase in the shelf-life of the oil.

CONCLUSION

The gPPI-CUR conjugates enhanced the oxidative stability of walnut oil significantly, as demonstrated by the increased shelf life and reduced lipid oxidation. This study introduced an effective encapsulation method that improved the stability and extended the shelf life of edible oils, aligning with consumer demands for high-nutrition food products. The results indicate that the gPPI-CUR conjugates could serve as a promising antioxidant strategy for food preservation, offering a practical approach to enhance food quality and safety. © 2025 Society of Chemical Industry.

Effect of Extraction Methods and Preheat Treatments on the Functional Properties of Pumpkin Seed Protein Concentrate

This study explores the effect of different extraction methods and preheat treatments in obtaining protein concentrate from pumpkin seed flour. The effects on the yield and functional properties of pumpkin seed protein concentrate (PSPC) were compared alongside microwave and conventional preheating methods using alkali, salt, and enzyme-assisted alkali extraction techniques. Analytical assessments included proximate analysis, soluble protein content, water solubility index (WSI), emulsification activity (EA) and stability (ES), foaming capacity (FC) and stability (FS), and antioxidant activity (AA). Hydration and structural analyses were performed via time-domain nuclear magnetic resonance (TD-NMR) Relaxometry and Fourier-Transform Infrared (FTIR) Spectroscopy. In addition, color measurements were performed to evaluate the visual quality of the samples. The alkali extraction method paired with microwave heating (MH-AE) significantly outperformed other techniques, with an extraction yield and protein content of approximately 55% and 77%, respectively. This study demonstrated the superior yield and functional properties of PSPC using MH-AE, opening opportunities for future research in optimizing plant-based protein extraction techniques.

Identification and molecular mechanism of novel antioxidant peptide from fish sauce: A combined quantum chemistry and molecular simulation

Fish sauce, derived from fermented fish, exhibits a notable antioxidant effect after a six-month fermentation process, and we propose that potential antioxidant peptides were present in the fish sauce. We isolated, purified, and identified potential bioactive antioxidant peptides by using fish sauce fermented for 6 months. Additionally, molecular simulation was employed to investigate the antioxidant action mechanism of these bioactive peptides. The molecular docking results revealed that FS4-1 (MHQLSKK), FS4-2 (VLDNSPER), FS4-3 (MNPPAASIK), FS6-1(VLKQAAAGR), and FS6-2 (SPDVSPRR), could dock with the Keap1 receptor. The primary force (Van der Waals' force and hydrogen bonds) and key sites (GLY509 and ALA510) of Keap1 binding to peptides were determined. The active center was located in the side chain of amino acid Met at positions C7H78 and C7H79. We here identified antioxidant peptides in fish sauce and revealed the antioxidant mechanism through molecular simulations.

Metabolomic investigation of fresh beef, lamb and venison using nuclear magnetic resonance spectroscopy in relation to colour stability

This study investigated changes in the metabolome of fresh beef, lamb, and venison in relation to colour stability during display storage. Changes in meat colour and metabolites in loin muscles (Longissimus lumborum) of beef, lamb and venison were determined under a simulated retail display at 4 °C. Metabolite analysis was performed using nuclear magnetic resonance (NMR) spectroscopy, and 27 metabolites were identified. The stability of fresh meat colour was found to be in the following order: beef > lamb > venison. Several trends were observed, and amino acids and metabolites involved in ATP generation were found to be the most important. Leucine, isoleucine and valine were increased, whereas succinate, inosine monophosphate and choline were decreased over the storage time of all three meat types (p < 0.05). As a reduction in succinate, inosine monophosphate and choline during storage were found for all three meat types, these metabolites could potentially be associated with colour stability.

Phytochemical-mediated efferocytosis and autophagy in inflammation control

Efferocytosis, the clearance of apoptotic cells, is a critical process that maintains tissue homeostasis and immune regulation. Defective efferocytosis is linked to the development of chronic inflammatory conditions, including atherosclerosis, neurological disorders, and autoimmune diseases. Moreover, the interplay between autophagy and efferocytosis is crucial for inflammation control, as autophagy enhances the ability of phagocytic cells. Efficient efferocytosis, in turn, regulates autophagic pathways, fostering a balanced cellular environment. Dysregulation of this balance can contribute to the pathogenesis of various disorders. Phytochemicals, bioactive compounds found in plants, have emerged as promising therapeutic agents owing to their diverse pharmacological properties, including antioxidant, anti-inflammatory, and immunomodulatory effects. This review aims to highlight the pivotal role of phytochemicals in enhancing efferocytosis and autophagy and explore their potential in the prevention and treatment of related disorders. This study examines how phytochemicals influence key aspects of efferocytosis, including phagocytic cell activation, macrophage polarization, and autophagy induction. The therapeutic potential of phytochemicals in atherosclerosis and neurological diseases is highlighted, emphasizing their ability to enhance efferocytosis and autophagy and reduce inflammation. This review also discusses innovative approaches, such as nanoformulations and combination therapies to improve the targeting and bioavailability of phytochemicals. Ultimately, this study inspires further research and clinical applications in phytochemical-mediated efferocytosis enhancement for managing chronic inflammatory and autoimmune conditions.

Enhanced Antioxidant and Digestive Enzyme Inhibitory Activities of Pacific White Shrimp Shell Protein Hydrolysates via Conjugation with Polyphenol: Characterization and Application in Surimi Gel

Pacific white shrimp shell protein hydrolysates (SSPHs) produced using alcalase (UAH) and papain (UPH), and polyphenols (PPNs) conjugates were prepared using variable concentrations (0.5-3% w/v) of different polyphenols (EGCG, catechin, and gallic acid). When 2% (v/v) of a redox pair was used for conjugation, 0.5% (w/v) of PPNs resulted in the highest conjugation efficiency (CE), regardless of the polyphenol types. However, CE decreased further with increasing levels of PPNs (p < 0.05). SSPHs at 2% retained the highest CE when combined with the selected PPN and redox pair concentrations (p < 0.05). FTIR and 1H-NMR analysis confirmed the successful conjugation of PPNs with the SSPHs. Among all the conjugates, EGCG conjugated with UAH (A-E) or UPH (P-E) exhibited the highest DPPH/ABTS radical scavenging, and metal chelating activities, respectively. The highest FRAP activity was noticed for A-E conjugate followed by UAH-catechin (A-C) and UPH-catechin (P-C) conjugates. The A-C sample (6 mg/mL) demonstrated the strongest inhibition efficiency against α-amylase, α-glucosidase, and pancreatic lipase (89.29, 81.23, and 80.69%, respectively) than other conjugates (p < 0.05). When A-C conjugate was added into surimi gels prepared from Indian mackerel (IM) and threadfin bream (TH) mince at various levels (2-6%; w/w), gel strength, and water holding capacity was increased in a dose-dependent manner, regardless of surimi type. However, whiteness decreased with increasing A-C levels. After the in vitro digestion of surimi gels, antioxidant and enzyme inhibitory activities were also increased as compared to the digest prepared from control surimi gels (added without A-C conjugate). Thus, waste from the shrimp industry in conjugation with plant polyphenols could be utilized to produce antioxidant and antidiabetic or anti-obesity agents, which could be explored as a promising additive in functional foods and nutraceuticals.

Preparation, Characterization, Stability and In Vitro Release of a Pea Protein Fibril-Based Iron Fortificant via Self-Assembly

It is assumed that the stability and bioaccessibility of iron ions in iron-pea protein fibril (Fe-Fib PP) nanocomposite can be remarkably enhanced, and Fe-Fib PP exhibits great potential as an effective iron fortificant. Fe-Fib PP, a stable and effective iron supplement, was fabricated based on the reducing property of pea protein fibrils, derived from pea protein through thermal treatment at pH 2.0. The results demonstrated that the reducing power of iron was remarkably affected by fibril concentration and fibrillization degree. The reducing power of pea protein fibrils gradually enhanced from 0.31 to 0.92 with the increase in incubation time from 0 to 48 h. Compared with iron nanoparticles (Fe-Nano), Fe-Fib PP possessed much higher dispersibility. Additionally, the stability of iron in Fe-Fib PP was significantly higher than that in Fe-Nano under different storage conditions. X-ray photoelectron spectroscopy (XPS) outcomes revealed Fe (II) content in Fe-Fib PP (70.75 ± 0.65%) was remarkably higher than that of Fe-Nano (56.05 ± 0.50%). In addition, the bioaccessibility of Fe (II) dramatically improved from 42.7% to 62.8% using PP fibrils as carriers. The findings suggest that Fe-Fib PP is an effective iron nutrition enhancer.

Evidence-based sports supplements: A redox analysis

Despite the overwhelming number of sports supplements on the market, only seven are currently recognized as effective. Biological functions are largely regulated through redox reactions, yet no comprehensive analysis of the redox properties of these supplements has been compiled. Here, we analyze the redox characteristics of these seven supplements: bicarbonates, beta-alanine, caffeine, creatine, nitrates, carbohydrates, and proteins. Our findings suggest that all sports supplements exhibit some degree of redox activity. However, the precise physiological implications of these redox properties remain unclear. Future research, employing unconventional perspectives and methodologies, will reveal new redox pixels of the exercise physiology and sports nutrition picture.

Response surface optimization of protein extraction from cold-pressed terebinth (Pistacia terebinthus L.) oil byproducts: Physicochemical and functional characteristics

The current study focused on optimizing the extraction parameters of terebinth seed proteins from cold-pressed terebinth oil byproducts to maximize protein purity and protein yield. The isolated proteins were characterized to evaluate their properties; thus revealing the valorization potential of these byproducts. Response surface methodology was used to detect the effect of three extraction parameters (pH, temperature, and time). The protein isolates were studied for their physicochemical and functional characteristics. The results indicated that an extraction pH of 8, a temperature of 50°C, and an extraction period of 60 min are optimum conditions for obtaining protein isolates with the highest purity. On the other hand, it was demonstrated that an extraction pH of 12, a temperature of 46.4°C, and an extraction duration of 102.4 min were optimum conditions for the maximum protein yield. The proteins produced under these two sets of conditions, referred to as TRP (terebinth protein with maximum purity) and TRY (terebinth protein with maximum yield), respectively, exhibited comparable oil absorption capacity (OAC), foaming, emulsifying capabilities, and stability. Both proteins showed the highest solubility at pH 11, and their zeta potentials approached zero at pH 4, indicating proximity to their isoelectric points. However, FRAP and DPPH assays showed that TRP and TRY offered low antioxidative capacity. The high β-sheet content in TRP and TRY suggests enhanced thermal stability but reduced digestibility of these proteins. Therefore, in addition to protein enrichment, TRP and TRY protein isolates can be utilized in muffins and other food applications thanks to their favorable oil absorption, foaming and emulsifying capacities, and thermal stabilities.

Bioactive proteins and antioxidant peptides from Litsea cubeba fruit meal: Preparation, characterization and ameliorating function on high-fat diet-induced NAFLD through regulating lipid metabolism, oxidative stress and inflammatory response

Non-alcoholic fatty liver disease (NAFLD) plays an increasingly significant threat to human health. In this study, the processing by-products of Litsea cubeba fruit meal were defatted by ultrasound-assisted methods, then the acetone-precipitated protein of L. cubeba (LCP) was obtained and structural analysis was performed. LCP was hydrolyzed by a two-step sequential hydrolysis method using alcalase and papain. Subsequently, antioxidant peptide fraction (IV2) was isolated and identified from the resultant hydrolysate through membrane ultrafiltration, Sephadex G-15 chromatography, and liquid chromatograph mass spectrometer (LC-MS). Animal experimentation indicated the potential of IV2 to mitigate hepatic steatosis. Moreover, IV2 could effectively reduce oxidative stress-induced damage by modulating the Keap1-Nrf2 pathway to activate downstream heme oxygenase-1 (HO-1) and NAD(P) H quinone oxidoreductase 1 (NQO1). Integrating metabolomics and transcriptomics revealed enrichment in pathways associated with glycerolipid metabolism and fatty acid β-oxidation, suggesting the principal mechanisms underlying IV2's ameliorative effects on NAFLD. Transcriptome sequencing identified 3092 up-regulated and 3010 down-regulated genes following IV2 treatment. Interaction analyses based on different lipid compositions (DELs) and differentially expressed genes (DEGs) indicated that IV2 primarily alleviated hepatic steatosis by modulating peroxisome proliferator-activated receptor α (PPAR-α) related pathways, thereby augmenting fatty acid β-oxidation within liver cells. These results indicate that IV2 shows potential in improving high-fat diet (HFD)-induced NAFLD, with improved fatty acid β-oxidation and reduced triglyceride biosynthesis emerging as underlying mechanisms.

Exploring the nutritional and biological properties of green coffee extracts: A comparative study of aqueous and enzymatic extraction processes

The effects of aqueous (AEP) and enzyme-assisted aqueous extraction processes (EAEP) on the biological and nutritional properties of green coffee extracts (protein and antioxidant-rich fraction) were investigated. All extracts exhibited high in vitro protein digestibility (>98%), regardless of the pH and use of enzymes during extraction, probably due to the low molecular weight of coffee proteins. Raising extraction pH from 7.0 to 9.0 resulted in extracts with lower concentrations of caffeine and some phenolic compounds such as chlorogenic and cinnamic acids, as well as catechin and epicatechin. This led to a reduction in the antioxidant activity of the extracts obtained at alkaline pH (AEP - pH 9.0). Overall, higher phenolic and caffeine extractability was achieved at neutral pH (AEP - pH 7.0), with no observed improvement in extraction yields when carbohydrases and/or proteases were employed. Coffee extracts generated by AEP at pH 7.0 exhibited the highest lipase inhibitory activity (66%), primarily attributed to their higher chlorogenic acid concentration. Conversely, EAEP extracts exhibited higher angiotensin-converting enzyme inhibition (up to 85%) compared to AEP extracts (68.5-74.3%). This strong inhibitory activity is likely related to the presence of both phenolic compounds (mainly chlorogenic acid) and smaller peptides. Nevertheless, all extracts exhibited low effectiveness for α-glucosidase inhibition (≤14%) and antimicrobial activity against S. aureus and E. coli. The current research underscores the feasibility of modulating the composition of green coffee extracts using sustainable and scalable AEP and EAEP, paving the way for developing tailored extracts with specific biological properties.

Purification, Structural Characterization, and Bioactivity of Amaranthus hypochondriacus Lectin

Lectin extracted from Amaranthus hypochondriacus was purified using an affinity column with an agarose-fetuin matrix specific to the lectin of interest. Purification was confirmed by SDS-PAGE, revealing a single protein band with a molecular mass of 34.4 kDa. A hemagglutination assay showed that the lectin had a higher affinity for human type A erythrocytes, and its hemagglutinating activity was inhibited only by fetuin, not by mono-, di-, or trisaccharides. This demonstrated the lectin's selectivity for the N-acetylgalactosamine present on the surface of type A erythrocytes and fetuin. Amaranth lectin exhibited antioxidant activity, which was attributed to the phenolic compounds, amino acids, and specific peptides within the protein structure that are known for their antioxidant properties. Infrared (IR) spectroscopy provided a structural analysis and confirmed lectin glycosylation, a crucial factor in its stability and its ability to bind specific glycans on cell surfaces. Cu2+, Mn2+, and Zn2+ ions were found in the lectin, and these ions were strongly bound to the protein, as dialysis against ethylenediaminetetraacetic acid (EDTA) did not remove them. pH and temperature influenced lectin stability, with higher hemagglutinating activity observed at pH 7, and it remained thermostable at 25 °C.

Harnessing the nutritional profile and health benefits of millets: a solution to global food security problems

India is dealing with both nutritional and agricultural issues. The maximum area of agricultural land with irrigation capabilities has been largely utilized, while the amount of dry land is expanding. The influence is distinct on farmer's livelihoods and earnings, which ultimately affects nutritional security. In order to attain nutritional security and the goal of SDG (Sustainable Development Goals), millets are sustainable solutions, with respect to high nutritional content, bioactive and medicinal properties, and climate resilience. The nutrient profile of millet includes 60%-70% carbohydrate content, 3.5%-5.2% fat, and 7.52%-12.1% protein sources. A wide spectrum of amino acids, including cysteine, isoleucine, arginine, leucine, tryptophan, lysine, histidine, methionine, tyrosine, phenylalanine, threonine, and valine are generally present in millets. Mineral content in millets includes calcium, phosphorus, potassium, sodium, and magnesium. Additionally, millets are an excellent source of bioactive molecules such as polyphenol, phenolic acid, flavonoids, active peptides, and soluble fiber, which have a wide range of therapeutic applications, including the prevention of free radical damage, diabetes, anti-microbial, anti- biofilm, and anti-cancer effects. This review will focus on the nutritional profile and health benefits of millet considering the present-day food security problems.

Antioxidative, Glucose Management, and Muscle Protein Synthesis Properties of Fish Protein Hydrolysates and Peptides

The marine environment is an excellent source for many physiologically active compounds due to its extensive biodiversity. Among these, fish proteins stand out for their unique qualities, making them valuable in a variety of applications due to their diverse compositional and functional properties. Utilizing fish and fish coproducts for the production of protein hydrolysates and bioactive peptides not only enhances their economic value but also reduces their potential environmental harm, if left unutilized. Fish protein hydrolysates (FPHs), known for their excellent nutritional value, favorable amino acid profiles, and beneficial biological activities, have generated significant interest for their potential health benefits. These hydrolysates contain bioactive peptides which are peptide sequences known for their beneficial physiological effects. These biologically active peptides play a role in metabolic regulation/modulation and are increasingly seen as promising ingredients in functional foods, nutraceuticals and pharmaceuticals, with potential to improve human health and prevent disease. This review aims to summarize the current in vitro, cell model (in situ) and in vivo research on the antioxidant, glycaemic management and muscle health enhancement properties of FPHs and their peptides.

Antihypertensive and antioxidant effects of food-derived bioactive peptides in spontaneously hypertensive rats

Hypertension significantly impacts the survival and quality of life of animals, often leading to chronic kidney failure. Current clinical drugs used to manage hypertension carry the risk of causing adverse reactions. In contrast, certain natural peptides have demonstrated the ability to safely reduce blood pressure by inhibiting the production of angiotensin. We administered four biologically active peptide solutions to spontaneously hypertensive rats: derived from corn, wheat, egg white, and soybean. The efficacy of these peptides in reducing blood pressure was assessed through regular measurements of systolic pressure. Additionally, we analyzed levels of angiotensin-converting enzyme and angiotensin 2 using immunohistochemistry and ELISA in vivo. The indicators of oxidative stress and inflammation in hypertensive rats were evaluated using qRT-PCR and ELISA, respectively. Both wheat (from 182.5 ± 12.26 mmHg at day 0 to 168.86 ± 5.86 mmHg at day 20, p = .0435) and soybean (from 189 ± 2.19 mmHg at day 0 to 178.25 ± 5.14 mmHg at day 20, p = .0017) notably lowered systolic blood pressure compared to their starting systolic blood pressures in spontaneously hypertensive rats. Both wheat and soybean peptides significantly reduced plasma ANG II levels, akin to captopril's effect. Wheat peptides additionally exhibited antioxidant properties. Only the corn peptide showed a significant increase in transcript levels of the proinflammatory factors IL-6 and TNF-α. At the protein level, all four kinds of peptides significantly elevated IL-6 levels while inhibiting TNF-α secretion. This study demonstrates that wheat peptides and soybean peptides administered as dietary supplements exhibit significant hypotensive and antioxidant effects.

Candidate-Probiotic Lactobacilli and Their Postbiotics as Health-Benefit Promoters

Lactobacillus species are widely recognized for their probiotic potential, focusing on their mechanisms of health benefits and protection. Here we conducted an in vitro investigation of the probiotic potential with a role in microbiome homeostasis of four strains: Lactiplantibacillus plantarum L6 and F53, Ligilactobacillus salivarius 1, and Lactobacillus helveticus 611. A broad spectrum of antibacterial and antifungal activity was determined. The strain-specific inhibition of Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, and saprophytic/toxigenic fungi makes them promising as protective cultures. DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid) measurements showed that tested samples had strain-specific capacity for scavenging of radicals. The molecular base for the antioxidant potential of two lyophilized forms of active strains was investigated by electron paramagnetic resonance spectroscopy. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, with fractions of the most active postbiotics obtained by SEC-FPLC (fast protein liquid chromatography) analysis, showed a wide variety of effects on the growth of a K562 myeloid leukemia cell line. The IC50 (half-maximal inhibitory concentration) of L. salivarius 1 was determined to be 46.15 mg/mL. The proven in vitro functionality of the selected lactobacilli make them suitable for development of target probiotics with specific beneficial effects expected in vivo. Further investigations on produced postbiotics and safety have to be completed before they can be considered as scientifically proven probiotic strains.

Upgrading the Bioactive Potential of Hazelnut Oil Cake by Aspergillus oryzae under Solid-State Fermentation

Hazelnut oil cake (HOC) has the potential to be bioactive component source. Therefore, HOC was processed with a solid-state fermentation (SSF) by Aspergillus oryzae with two steps optimization: Plackett-Burman and Box-Behnken design. The variables were the initial moisture content (X1: 30-50%), incubation temperature (X2: 26-37 °C), and time (X3: 3-5 days), and the response was total peptide content (TPC). The fermented HOC (FHOC) was darker with higher protein, oil, and ash but lower carbohydrate content than HOC. The FHOC had 6.1% more essential amino acid and benzaldehyde comprised 48.8% of determined volatile compounds. Fermentation provided 14 times higher TPC (462.37 mg tryptone/g) and higher phenolic content as 3.5, 48, and 7 times in aqueous, methanolic, and 80% aqueous methanolic extract in FHOC, respectively. FHOC showed higher antioxidant as ABTS+ (75.61 µmol Trolox/g), DPPH (14.09 µmol Trolox/g), and OH (265 mg ascorbic acid/g) radical scavenging, and α-glucosidase inhibition, whereas HOC had more angiotensin converting enzyme inhibition. HOC showed better water absorption while FHOC had better oil absorption activity. Both cakes had similar foaming and emulsifying activity; however, FHOC produced more stable foams and emulsions. SSF at lab-scale yielded more bioactive component with better functionality in FHOC.

Comparative study on the bioavailability of peptide extracts from Jeju black pigs and three-way crossbred pigs

This study aimed to compare the changes in the bioactivities of peptide extracts (< 10 kDa) obtained from Jeju black pigs (JBP) and three-way crossbred pigs (Landrace × Yorkshire × Duroc, LYD) before and after digestion. The results showed that the loin peptide extracts of JBP maintained high 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity after in vitro digestion. However, the iron chelating activity and antihypertensive activity of all peptide extracts were decreased. This study suggested that the peptide extracts produced through alkaline-AK digestion have sufficiently high antioxidant and antihypertensive activities; however, these activities were reduced after in vitro digestion. Meanwhile, the JBP loin and ham peptide extracts promoted high superoxide dismutase (SOD) activity than that of LYD when administered to mice. Furthermore, the ham peptide extracts of JBP showed a relatively high antihypertensive activity in mice. Therefore, it is deemed that these peptide extracts from JBP are more bioactive than that of LYD, and can be used as bioactive materials.

An Innovative Bio-Vehicle for Resveratrol and Tocopherol Based on Quinoa 11S Globulin-Nanocomplex Design and Characterization

Nanocomplexes, which possess immense potential to function as nanovehicles, can link diverse ligand compounds. The objective of the present study was to design and characterize resveratrol (RSV)- and tocopherol (TOC)-loaded 11S quinoa seed protein nanocomplexes. Firstly, molecular docking was performed to describe the probable binding sites between protein and ligands, and binding energies of -5.6 and -6.2 kcal/mol were found for RSV and TOC, respectively. Isothermal titration calorimetry allowed us to obtain the thermodynamic parameters that described the molecular interactions between RSV or TOC with the protein, finding the complexation process to be exothermic and spontaneous. 11S globulin intrinsic fluorescence spectra showed quenching effects exerted by RSV and TOC, demonstrating protein-bioactive compound interactions. The application of Stern-Volmer, Scatchard, and Förster resonance energy transfer models confirmed static quenching and allowed us to obtain parameters that described the 11S-RSV and 11S-TOC complexation processes. RSV has a higher tendency to bind 11S globulin according to ITC and fluorescence analysis. Secondly, the protein aggregation induced by bioactive compound interactions was confirmed by dynamic light scattering and atomic force microscopy, with diameters <150 nm detected by both techniques. Finally, it was found that the antioxidant capacity of a single 11S globulin did not decrease; meanwhile, it was additive for 11S-RSV. These nanocomplexes could constitute a real platform for the design of nutraceutical products.

Characterization and molecular docking of tetrapeptides with cellular antioxidant and ACE inhibitory properties from cricket (Acheta domesticus) protein hydrolysate

Wide-ranging bioactivities of enzymatically digested insect protein to produce peptides have been targeted for functional food development. In this study, fractionated peptides obtained from cricket (Acheta domesticus) protein hydrolysate by alcalase digestion were identified and evaluated for their bioactivities. Peptide fractions F44, F45, and F46, isolated through size exclusion chromatography, demonstrated strong cytoprotective effects on SH-SY5Y and HepG2 cells exposed to H2O2. This was evidenced by a 2-fold decrease in reactive oxygen species (ROS) accumulation in the cells and a 3-fold upregulation of genes encoding antioxidant enzymes. The F45 peptide fractions also showed chemical antioxidant activities ranging from approximately 290 to 393 mg trolox/g peptide, measured by DPPH, ABTS, and FRAP assays. Furthermore, F45 demonstrated the highest angiotensin-converting enzyme I (ACE) inhibitory activity, 57.93 %. F45 induced higher levels of Nrf2, SOD1, SOD2, CAT, GSR, and GPx4 gene expression in SH-SY5Y and HepG2 cells compared to cells treated with H2O2 and no peptides (p < 0.05). Cells treated with H2O2 and F45 exhibited significantly increased antioxidant enzyme activity, including SOD, CAT, GSR, and GPx (p < 0.05). The F45B fraction from F45 was sequenced to obtain FVEG and FYDQ tetrapeptides. Molecular docking analysis revealed their high binding affinity to cellular antioxidant enzymes (SOD, CAT, GSR, GPx1, and GPx4), an antioxidant-related protein (Keap1), and ACE. These results suggest that the novel tetrapeptides from Acheta domesticus demonstrate important biological activities, establishing them as significant cellular antioxidant activities and a potential source of antihypertensive peptides.

The Impact of Thermal Treatment Intensity on Proteins, Fatty Acids, Macro/Micro-Nutrients, Flavor, and Heating Markers of Milk-A Comprehensive Review

Milk thermal treatment, such as pasteurization, high-temperature short-time processing, and the emerging ultra-short-time processing (<0.5 s), are crucial for ensuring milk safety and extending its shelf life. Milk is a nutritive food matrix with various macro/micro-nutrients and other constituents that are possibly affected by thermal treatment for reasons associated with processing strength. Therefore, understanding the relationship between heating strength and milk quality is vital for the dairy industry. This review summarizes the impact of thermal treatment strength on milk's nutritional and sensory properties, the synthesizing of the structural integrity and bioavailability of milk proteins, the profile and stability of fatty acids, the retention of macro/micro-nutrients, as well as the overall flavor profile. Additionally, it examines the formation of heat-induced markers, such as Maillard reaction products, lactulose, furosine, and alkaline phosphatase activity, which serve as indicators of heating intensity. Flavor and heating markers are commonly used to assess the quality of pasteurized milk. By examining former studies, we conclude that ultra-short-time-processing-treated milk is comparable to pasteurized milk in terms of specific parameters (such as whey protein behavior, furosine, and ALP contents). This review aims to better summarize how thermal treatments influence the milk matrix, guiding the dairy industry's development and balancing milk products' safety and nutritional value.

Spatiotemporal assessment of protein and lipid oxidation in concentrated oil-in-water emulsions stabilized with legume protein isolates

The growing trend of substituting animal-based proteins with plant-based proteins requires more understanding of the functionality and stability of vegan mayonnaises, especially regarding their susceptibility to lipid and protein oxidation. Here, we investigate the spatial and temporal dynamics of lipid and protein oxidation in emulsions stabilized with legume ((hydrolyzed) soy, pea, and faba bean) protein isolates (hSPI, SPI, PPI, FPI). We assessed lipid oxidation globally by NMR and locally by confocal laser scanning microscopy using the oxidation-sensitive fluorescent dye BODIPY 665/676. Further, we assessed local protein oxidation by employing protein autofluorescence and the fluorescently labeled radical spin-trap CAMPO-AFDye 647. Oxidation of oil in droplets was governed by the presence of tocopherols in the oil phase and pro-oxidant transition metals that were introduced via the protein isolates. Non-stripped oil emulsions stabilized with PPI and hSPI displayed higher levels of lipid hydroperoxides as compared to emulsions prepared with SPI and FPI. We attribute this finding to higher availability of catalytically active transition metals in PPI and hSPI. For stripped oil emulsions stabilized with SPI and FPI, lipid hydroperoxide concentrations were negligible in the presence of ascorbic acid, indicating that this agent acted as antioxidant. For the emulsions prepared with PPI and hSPI, lipid hydroperoxide formation was only partly inhibited by ascorbic acid, indicating a role as prooxidant. Interestingly, we observed protein-lipid aggregates in all emulsions. The aggregates underwent fast and extensive co-oxidation, which was also modulated by transition metals and tocopherols originating from the oil phase. Our study demonstrates the potential of spatiotemporal imaging techniques to enhance our understanding of the oxidation processes in emulsions stabilized with plant proteins.

Multifunctional and edible egg white/amylose-tannin bilayer film for perishable fruit preservation

The substantial waste of perishable foods during transportation significantly contributes to greenhouse gas emissions, intensifying the climate crisis. To mitigate the rapid spoilage of fruits, an eco-friendly bilayer film was developed using natural egg white (EW), amylose (Am), and tannic acid (TA). The EW/Am-TA bilayer film features a primary layer of amphiphilic EW, ensuring a uniform coating on hydrophobic fruit surfaces, and a secondary layer composed of Am and TA, imparting notable tensile strength (5.3 ± 0.5 MPa) and elongation at break (28.5 ± 4.1 %). This bilayer film effectively shields fruits from UV-B and UV-C radiation (~0 % transmittance at 280 and 330 nm) and exhibits antioxidant and antibacterial properties due to the presence of TA. Fruits such as bananas, avocados, and cherry tomatoes, when dip-coated with the optimized EW/Am-TA bilayer, maintained their freshness, color, weight, and texture for up to seven days, demonstrating the effectiveness of this bilayer coating in food preservation. The natural materials in the coated film are edible and can be safely removed with tap water at room temperature in <10 s, posing no food safety risks. Thus, the proposed bilayer coating presents a significant solution to the global problem of food waste.

Upcycling of Defatted Sesame Seed Meal via Protein Amyloid-Based Nanostructures: Preparation, Characterization, and Functional and Antioxidant Attributes

Herein, the possibility of valorizing defatted sesame seed meal (DSSM) as a viable source for valuable plant proteins and amyloid-based nanostructure was investigated. Sesame seed protein isolate (SSPI) and the major storage protein globulin (SSG) were prepared by alkaline extraction-isoelectric point precipitation as well as fractionation in the case of SSG. The protein samples were characterized for their physicochemical attributes. SSPI and SSG were also evaluated for their ability to form amyloid structures under heating (90 °C) at low pH (2.0). Additionally, the functional attributes, antioxidant activity, and biocompatibility of the proteins and amyloid nanostructures were also examined. SSPI and SSG were both successfully prepared from DSSM. The data showed that the physicochemical attributes of both protein samples were quite similar, except for the fact that SSG was mostly composed of 11S globulin, as evinced by Tricine-SDS-PAGE analysis. TEM micrographs revealed that SSG was able to form curly-shaped fibrillar amyloid structures, whereas those derived from SSPI were mostly amorphous. Thioflavin-T assay and Tricine-SDS-PAGE analysis indicated that acidic heating promoted protein hydrolysis and self-aggregation of the hydrolyzed peptides into a β-sheet rich amyloid structure. Importantly, the amyloid preparations displayed commendable solubility, superior water and oil holding capacities, and antioxidant activity against DPPH and ABTS. The protein amyloid nanostructures were found to be non-toxic against RAW264.7 cells, HaCaT cells, and red blood cells. These findings indicate that DSSM could be upcycled into valuable protein amyloid structures with good potentialities as novel food ingredients.

Identification of Metabolites in Muscles of Lueyang Black-Bone Chickens: A Comparative Analysis of Caged and Cage-Free Rearing Modes Using Untargeted Metabolomic Techniques

The Lueyang black-bone chicken is a specific native chicken strain in China. This study aimed to investigate the effects of different rearing systems on the meat quality of Lueyang black-bone chickens. Six hundred Lueyang black-bone hens were randomly divided into two groups at 7 weeks of age and raised in cage and cage-free systems for 20 weeks. The carcass yield, meat quality, and total metabolites were measured in both the leg and breast muscles. By comparison, the carcass yield of hens in the cage-free (CF) group (1.26 ± 0.09 kg) was significantly lower than that in the caged rearing (CR) group (1.52 ± 0.15 kg). However, the shear force of leg muscles in the CF group (27.98 ± 2.43 N) was significantly greater than that in the CR group (24.15 ± 1.93 N). In addition, six samples from each group were randomly selected and their metabolites were detected by the non-targeted metabolomics technique. Among these metabolites, 408 and 354 significantly differentially abundant metabolites were identified in breast and leg muscles, which were mainly involved in glycerophospholipid metabolism, unsaturated fatty acid biosynthesis, arginine and proline metabolism, and nucleotide metabolism. We found that the levels of 19 phospholipids, mainly phosphatidylcholines and lysophosphatidylcholines, were significantly greater in the CF group than in the CR group. Additionally, the contents of eight unsaturated fatty acids, linoleic acid, and linolenic acid were dramatically greater in the CF group than in the caged group. The accumulation of 4-hydroxy-proline, glutamate, and adenosine 3'-monophosphate (AMP) was enhanced in the CF group. Moreover, many more volatile organic compounds were identified in the muscles of the cage-free group, enhancing the flavor of the chicken meat. In conclusion, the cage-free rearing mode facilitates the accumulation of nutrients and flavor substances in the chicken meat and is a better rearing system for Lueyang black-bone chickens.

Influence of emulsifier on lipid oxidation in spray-dried microencapsulated O/W emulsions

Lipid oxidation limits the shelf-life of dried microencapsulated oils (DMOs), such as infant formula. However, it is poorly understood how lipid oxidation is affected by different types of emulsifiers. To improve our understanding, we prepared DMOs with different emulsifiers (whey protein isolate (WPI), pea protein isolate (PPI), and non-proteinaceous CITREM) and studied lipid oxidation in both the free and encapsulated fat. Only a small difference in oxidation rate was observed between these fat fractions for all formulations. We ascribed this to a non-discrete distribution of the fractions and the subsequent low fractionation selectivity as shown by Raman microscopy. The DMO with PPI showed hardly any oxidation during a 7-week incubation at 40 °C, whereas the DMOs with WPI and CITREM both reached significantly higher contents of oxidation products (lipid hydroperoxides, aldehydes, and epoxides). The enhanced stability of DMO-PPI could not be ascribed to the presence of phytic acid. In conclusion, we demonstrate the potential of using PPI to produce oxidatively stable DMOs.

In Situ Nanoencapsulation of Curcumin in Soy Protein Isolate Amyloid-like Aggregates for Enhanced Wound Healing

The importance of amyloid nanofibrils made from food proteins is rising in diverse fields, such as biomedicine and food science. These protein nanofibrils (PNFs) serve as versatile and sustainable building blocks for biomaterials, characterized by their high β-sheet content and an ordered hydrogen bond network. These properties offer both stability and flexibility, along with an extreme aspect ratio and reactive functional groups. Plant-derived amyloid nanofibrils, such as soy protein isolate (SPI) PNFs, are increasingly favored due to their affordability and sustainability compared with animal proteins. This study aimed to explore the formation and application of SPI amyloid-like aggregates (SPIA) and their nanoencapsulation of curcumin (Cur) for biomedical purposes, particularly in wound healing. Under specific conditions of low pH and high temperature, SPIA formed, exhibited an amyloid nature, and successfully encapsulated Cur, thereby enhancing its stability and availability. Spectroscopic and microscopic analyses confirmed structural changes in SPIA upon the incorporation of Cur and the fabrication of SPIA@Cur. The obtained results indicate that in the presence of Cur, SPIA forms faster, attributed to accelerated SPI denaturation, an increased nucleation rate, and enhanced self-assembly facilitated by Cur's hydrophobic interactions and π-π stacking with SPI peptides. In vitro studies demonstrated the biocompatibility, biodegradability, and antioxidant properties of SPIA@Cur along with controlled release behavior. In vivo experiments in male Wistar rats revealed that both SPIA and SPIA@Cur significantly accelerate wound closure compared with untreated wounds, with SPIA@Cur showing slightly better efficacy. The histological analysis supported enhanced wound healing, indicating the potential of SPIA@Cur for biomedical applications.

Characterization of peptides released from frozen-then-aged beef after digestion in an in vitro infant gastrointestinal model

This study investigated whether the freezing-then-aging treatment of beef affects protein digestibility and release of potentially bioactive peptides using an in vitro infant digestion model. After 28 days of storage, aged-only (AO) and frozen-then-aged (FA) beef exhibited higher α-amino group contents in the 10% trichloroacetic acid-soluble fraction compared to day 0 (P < 0.05). Following in vitro digestion in the infant model, FA showed higher contents of α-amino groups and smaller proteins (<3 and 1 kDa) than day 0 and AO (P < 0.05). Relative contributions of myofibrillar, sarcoplasmic, and stromal proteins to the bioactive peptides released from AO and FA differed from those of day 0. In addition, FA exhibited a higher proportion of potential bioactive peptide sequences. Overall, freezing-then-aging treatment can enhance the potential health benefits of beef to be used as a protein source for complementary foods.

HPLC purification of antioxidant and antibacterial peptides from a lichen "Parmotrema perlatum (Huds.) M. Choisy": Identification by LC-MS/MS peptide mass fingerprinting

Parmotrema perlatum, a lichen belonging to the family Parmeliaceae, is well known for its culinary benefits and aroma used as a condiment in Indian homes is also known as the "black stone flower" or "kalpasi" in India. This research intends to analyze the antioxidant power of the crude extracts using four pH-based buffers solubilized proteins/peptides and RP-HPLC fractions of P. perlatum obtained by purification. The proteins that were extracted from the four different buffers were examined using LC-MS/MS-based peptide mass fingerprinting. When compared to the other buffers, the 0.1 M of Tris-HCl buffer pH 8.0 solubilized proteins/peptides had the strongest antioxidant capacity. The sequential purification of the peptide was carried out by using a 3-kDa cut-off membrane filter and semipreparative RP-HPLC. Additionally, the purified fractions of the peptide's antioxidant activity were assessed, and effects were compared with those of the crude and 3 kDa cut--off membrane filtrates. The peptide fractions were sequenced by LC-MS/MS, which reveals that fraction 2 from RP-HPLC with the sequence LSWFMVVAP has shown the highest antioxidant potential in comparison with other fractions which can serve as the potential natural antioxidant drug. Further, fraction 2 also showed antibacterial activity against the selected microorganisms.

Employing fruit juices to hydrolyze edible bird's nest and enhance the antioxidant, anti-tyrosinase, and wound-healing activities of the hydrolysates

Enzymatic hydrolysis of edible bird's nest (EBN) has attracted great interest in both scientific and commercial fields due to the enhancement of solubility and nutraceutical values. The present study attempted to investigate the hydrolysis of EBN with papaya (Carica papaya L.), pineapple (Ananas comosus (L.) Merr.), and cantaloupe (Cucumis melo L.) juices as well as two commercial enzymes papain and bromelain. Our analysis revealed that EBN hydrolysis with pineapple juice and bromelain produced a degree of hydrolysis (DH) value of approximately 27 % while it was about 25 % for the hydrolysis with cantaloupe juice and 22 % for the hydrolysis with papaya juice and papain after 4 h of treatment. When EBN was digested by fruit juices and enzymes, the protein solubility and free sialic acid content were increased and the highest values were achieved for EBN hydrolysis with pineapple juice and bromelain (estimately 11 mg/mL of soluble protein and 18 g/kg of free sialic acid). The ABTS•+-scavenging, •OH-scavenging, and anti-tyrosinase capacities were higher in the EBN hydrolysates by papaya juice (IC50 of 0.034, 0.108, and 0.419 mg/mL, respectively), pineapple juice (IC50 of 0.025, 0.045, and 0.190 mg/mL, respectively), and cantaloupe juice (IC50 of 0.031 mg/mL, 0.056, and 0.339 mg/mL, respectively) than in the hydrolysates by unhydrolyzed EBN (IC50 of 0.094, 0.366, and 1.611 mg/mL, respectively). An improvement in ABTS•+-scavenging, •OH-scavenging, and anti-tyrosinase abilities was also observed for the hydrolysates by papain (IC50 of 0.041, 0.129, and 0.417 mg/mL, respectively) and bromelain (IC50 of 0.025, 0.069, and 0.336 mg/mL, respectively) but in a lesser extent as compared to the hydrolysates by respective papaya and pineapple juices. Noticeably, the EBN hydrolysates by fruit juices remarkably enhanced the wound closure in human fibroblasts by about 1.4-1.8 times after 24 h of treatment whereas this property was insignificant in the hydrolysates by enzymes. As papaya, pineapple, and cantaloupe juices are easily obtainable and have pleasant flavors, our results provide a possible method to hydrolyze EBN and apply the resultant hydrolysates in functional food products.

Amino acid HPLC-FLD analysis of spirulina and its protective mechanism against the combination of obesity and colitis in wistar rats

Objective

The cafeteria diet (CD), designed as an experimental diet mimicking the obesogenic diet, may contribute to the pathogenesis of inflammatory bowel diseases (IBD). This study delves into the influence of spirulina (SP) on obesity associated with colitis in Wistar rats.

Methods

The amino acids composition of SP was analyzed using HPLC-FLD. Animals were equally separated into eight groups, each containing seven animals and treated daily for eight weeks as follows: Control diet (SD), cafeteria diet (CD) group, CD + SP (500 mg/kg) and SD + SP. Ulcerative colitis was provoked by rectal injection of acetic acid (AA) (3 % v/v, 5 ml/kg b.w.) on the last day of treatment in the following groups: SD + AA, SD + AA + SP, CD + AA, and CD + AA + SP.

Results

Findings revealed that UC and/or CD increased the abdominal fat, weights gain, and colons. Moreover, severe colonic alteration, perturbations in the serum metabolic parameters associated with an oxidative stress state in the colonic mucosa, defined by overproduction of reactive oxygen species (ROS) and increased levels of plasma scavenging activity (PSA). Additionally, obesity exacerbated the severity of AA-induced UC promoting inflammation marked by the overexpression of pro-inflammatory cytokines. Significantly, treatment with SP provided notable protection against inflammation severity, reduced histopathological alterations, attenuated lipid peroxidation (MDA), and enhanced antioxidant enzyme activities (CAT, SOD, and GPX) along with non-enzymatic antioxidants (GSH and SH-G).

Conclusions

Thus, the antioxidant effects and anti-inflammatory proprieties of SP could be attributed to its richness in amino acids, which could potentially mitigate inflammation severity in obese subjects suffering from ulcerative colitis. These results imply that SP hold promise as a therapeutic agent for managing of UC, particularly in individuals with concomitant obesity. Understanding SP's mechanisms of action may lead novel treatment strategies for inflammatory bowel diseases and hyperlipidemia in medical research.

Phenolic Compounds Profile and Antioxidant Capacity of Plant-Based Protein Supplements

The study aimed to determine the phenolic content and antioxidant capacity of five protein supplements of plant origin. The content and profile of phenolics were determined using the UHPLC-DAD-MS method, while antioxidant capacity (ABTS and DPPH assays) and total phenolic content (TPC) were evaluated using spectrophotometric tests. In the analyzed proteins, twenty-five polyphenols were detected, including eleven phenolic acids, thirteen flavonoids, and one ellagitannin. Hemp protein revealed the highest individual phenolics content and TPC value (1620 μg/g and 1.79 mg GAE/g, respectively). Also, hemp protein showed the highest antioxidant activity determined via ABTS (9.37 μmol TE/g) and DPPH (9.01 μmol TE/g) assays. The contents of p-coumaric acid, m-coumaric acid, kaempferol, rutin, isorhamnetin-3-O-rutinoside, kaempferol-3-O-rutinoside, and TPC value were significantly correlated with antioxidant activity assays. Our findings indicate that plant-based protein supplements are a valuable source of phenols and can also be used in research related to precision medicine, nutrigenetics, and nutrigenomics. This will benefit future health promotion and personalized nutrition in the prevention of chronic diseases.

Analytical Methods and Effects of Bioactive Peptides Derived from Animal Products: A Mini-Review

Peptides with bioactive effects are being researched for various purposes. However, there is a lack of overall research on pork-derived peptides. In this study, we reviewed the process of obtaining bioactive peptides, available analytical methods, and the study of bioactive peptides derived from pork. Pepsin and trypsin, two representative protein digestive enzymes in the body, are hydrolyzed by other cofactors to produce peptides. Bicinchoninic acid assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, chromatography, and in vitro digestion simulation systems are utilized to analyze bioactive peptides for protein digestibility and molecular weight distribution. Pork-derived peptides mainly exhibit antioxidant and antihypertensive activities. The antioxidant activity of bioactive peptides increases the accessibility of amino acid residues by disrupting the three-dimensional structure of proteins, affecting free radical scavenging, reactive oxygen species inactivation, and metal ion chelating. In addition, the antihypertensive activity decreases angiotensin II production by inhibiting angiotensin converting enzyme and suppresses blood pressure by blocking the AT1 receptor. Pork-derived bioactive peptides, primarily obtained using papain and pepsin, exhibit significant antioxidant and antihypertensive activities, with most having low molecular weights below 1 kDa. This study may aid in the future development of bioactive peptides and serve as a valuable reference for pork-derived peptides.

Optimization of extraction parameters of protein isolate from milk thistle seed: Physicochemical and functional characteristics

In the current study, optimization of milk thistle protein extraction parameters was carried out in terms of purity and yield. In addition, the characterization of proteins isolated from milk thistle seeds was conducted. The optimal conditions for achieving the highest purity of protein (MTP) from milk thistle seeds were identified as extraction pH 9.47, temperature 30°C, and extraction time 180 min. Conversely, optimal values for overall protein yield (MTY) were determined at extraction pH 12, temperature 50°C, and extraction time 167 min. The proteins obtained under these two sets of conditions (MTP and MTY) demonstrated comparable oil absorption capacity (OAC), foaming, and emulsifying capabilities, as well as stability, aligning with findings from previous studies on seed protein. Both proteins had the highest protein solubilities at pH 11. Both proteins' zeta potentials were closest to zero at pH 4, demonstrating their closeness to the isoelectric point. MTP and MTY had poorer antioxidant capabilities than the other protein isolates/concentrates. MTP and MTY contain high β sheet concentrations that might enhance thermal stability and lower the digestibility of proteins. In conclusion, the protein extraction process demonstrated a high potential for achieving both substantial yield and remarkable purity with some decent technological and functional properties, thus holding promise for various applications in diverse fields.

Cyperus peptide SFRWQ inhibits oxidation and inflammation in RAW264.7 cell model

Oxidative stress can induce many diseases. Antioxidant peptides from food sources have the advantages of good safety, high activity, and good absorbability. In this study, a pentapeptide (SFRWQ; SER-PHE-ARG-TRP-GLN) was identified in a protein hydrolysate of Cyperus (Cyperus esculentus L.). Enzyme-linked immunosorbent assay (ELISA), real-time quantitative (qPCR), immunofluorescence and other techniques were used to evaluate the anti-inflammatory and antioxidant effects of SFRWQ. SFRWQ was found to have 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging ability, help increase superoxide dismutase (SOD) and catalase (CAT) levels in RAW264.7 cells, reduce reactive oxygen species (ROS) levels, and decrease tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) gene expression and secretion. The binding score of SFRWQ to recombinant Kelch-like ECH-associated protein 1 (Keap1) was greater than that of TX6. These findings suggest that SFRWQ activates the Keap1-Nrf2 cellular antioxidant signaling pathway. According to metabolomics studies, SFRWQ increased glutathione (GSH), glutathione disulfide (GSSG), and γ-glutamylcysteine levels and decreased the levels of Prostaglandin D2 (PGD2), Prostaglandin E2 (PGE2), and Prostaglandin H2 (PGH2), which are involved in arachidonic acid metabolism, to protect cells from LPS-induced damage. By elucidating the mechanism of action of SFRWQ, we provide a reference for the development of dietary antioxidant peptides.

Subcritical water-assisted fish gelatin hydrolysis for astaxanthin-loaded fish oil emulsion stability

Though gelatin emulsifying properties have been intensively studied, how low-molecular-weight (LMW) fish gelatin affects astaxanthin (AST)-loaded fish oil emulsion stability remains elusive. In this study, subcritical water hydrolysis (SWH)-modified LMW fish gelatin (SWHG) was produced from 110 °C to 180 °C and used to enhance the AST steadiness in oil/water emulsions in the presence of an emulsifier, lecithin. In the prepared emulsions, the surface charge increased while droplet size decreased with the decrease in gelatin MW due to the reduced thickness of the adsorbed gelatin membrane. LMW gelatin and lecithin could form a firm-absorbed layer on the droplet surface by electrostatic interaction between amide groups of gelatin molecules and phosphate groups of lecithin, thus stabilizing the emulsions. SWHG improved the creaming stability of the emulsions and hindered the oxygen- and light-induced AST degradation for 11 months compared to high MW gelatin. Whereas, the control emulsion showed noticeable phase separation after two weeks of storage. These findings prove the advantage of the SWH approach and propose the use of SWHG in oil-in-water emulsions for AST stabilization.

Effect of Nonprotein Components for Lipid Oxidation in Emulsions Stabilized by Plant Protein Extracts

Plant protein ingredients are rich in non-protein components of which the antioxidant and pro-oxidant effects are expected to be considerable. In this paper, commercial soy and pea protein isolates and concentrates were selected by using their soluble fractions to prepare oil-in-water (O/W) emulsions. Emulsions stabilized with soy protein isolates were more prone to lipid oxidation than those with soy protein concentrate or pea protein isolate. Compositional analysis revealed that the soluble fraction of soy protein isolates contained higher concentrations of phenolic compounds and metals (iron and copper) but lower mineral and ash contents than those of soy protein concentrate and pea protein isolate. Correlating the composition to oxidation in emulsions highlighted the significant role of non-protein components, alongside the protein's oxidative state. These findings are relevant for the use of alternative proteins in food formulation, a practice often promoted as sustainable yet that may come with repercussions for oxidative stability.

Biotechnological applications of amyloid fibrils

Protein aggregates and amyloid fibrils have special qualities and are used in a variety of biotechnological applications. They are extensively employed in bioremediation, biomaterials, and biocatalysis. Because of their capacity to encapsulate and release pharmaceuticals and their sensitivity to certain molecules, respectively, they are also used in drug delivery and biosensor applications. They have also demonstrated potential in the domains of food and bioremediation. Additionally, amyloid peptides have drawn interest in biological applications, especially in the investigation of illnesses like Parkinson's and Alzheimer's. The unique characteristics of amyloid fibrils, namely their mechanical strength and β-sheet structure, make them adaptable to a wide range of biotechnological uses. Even with their promise, one important factor to keep in mind before widely using modified amyloid materials is their potential toxicity. Thus, current research aims to overcome safety concerns while maximizing their potential.

Olive Pomace Extract Contains Low Molecular Weight Peptides and Possesses ACE Inhibitory Activity

The aim of the present study was to determine the ACE inhibitory activity of aqueous extracts of olive pomace and to understand whether they represent a good source of bioactive LMW peptides for nutritional and pharmacological applications. We produced a water extract from olive pomace (var. Picual) and obtained its low molecular weight (LMW) fraction (<3 kDa). The calculated yield of extraction was 100.2 ± 7.9 mg of LMW peptides per 100 g of olive pomace. The olive pomace LMW fraction possessed strong ACE inhibitory activity (IC50 = 3.57 ± 0.22 µg prot/mL). The LMW fraction (<3 kDa) was analysed by nanoscale liquid chromatography-Orbitrap coupled with tandem mass spectrometry and de novo sequencing. Thirty new peptides, containing between 7-17 amino acids and molecular masses ranging 778-1354 Da, were identified by the Peaks database algorithm using the available Olea europaea (cv. Farga) genome database. Ten new peptides were also identified by Peaks de novo sequencing. The protein sources of twelve peptides detected in the database by Peaks DB were identified by BLAST search. The ACE inhibitory activity of the identified peptides was predicted by BIOPEP software. We conclude that olive pomace possesses ACE inhibitory activity and contains low molecular weight peptides with (predicted) biological activity. Olive pomace may represent a good source of peptides for nutritional and pharmaceutical applications. In our study, it has been shown that olive pomace possesses ACE inhibitory activity and contains low molecular weight peptides with (predicted) biological activity. Olive pomace may represent a good source of peptides for nutritional and pharmaceutical applications. More research is needed in order to identify the in vivo effects of olive pomace bioactive peptides.

Lipid oxidation in emulsions: New insights from the past two decades

Lipid oxidation constitutes the main source of degradation of lipid-rich foods, including food emulsions. The complexity of the reactions at play combined with the increased demand from consumers for less processed and more natural foods result in additional challenges in controlling this phenomenon. This review provides an overview of the insights acquired over the past two decades on the understanding of lipid oxidation in oil-in-water (O/W) emulsions. After introducing the general structure of O/W emulsions and the classical mechanisms of lipid oxidation, the contribution of less studied oxidation products and the spatiotemporal resolution of these reactions will be discussed. We then highlight the impact of emulsion formulation on the mechanisms, taking into consideration the new trends in terms of emulsifiers as well as their own sensitivity to oxidation. Finally, novel antioxidant strategies that have emerged to meet the recent consumer's demand will be detailed. In an era defined by the pursuit of healthier, more natural, and sustainable food choices, a comprehensive understanding of lipid oxidation in emulsions is not only an academic quest, but also a crucial step towards meeting the evolving expectations of consumers and ensuring the quality and stability of lipid-rich food products.