The fasting hypoglycemic effect of casein hydrolysate (CH) was investigated in db/db diabetic-like mice using a multiomics integrated analysis of peptidome, transcriptome, and metabolome. Results showed that the oral administration of CH at a dose of 600 mg/kg/day for 4 weeks reduced the fasting blood glucose levels by 14.73 ± 9.77%, alleviated insulin resistance (HOMA-IR index) by 36.91 ± 22.62%, and mitigated hepatic damage in db/db diabetic-like mice. Hepatic differential metabolites after CH treatment were enriched in Glu-related metabolites, which acted as substrates for the TCA cycle, enhancing hepatic glucose consumption. The hepatic transcriptomic results revealed that CH treatment upregulated (p < 0.05) hub gene expressions of pparg and pik3cb, leading to an activation of the PPAR signaling pathway, further improving the insulin/PI3K/AKT signaling pathway. The hub gene expressions were highly correlated with Glu-related metabolites in multiomics integrated analysis. Glx/Glx-containing peptides (Glx represents Glu and Gln) in CH, as a dietary supplement to increase hepatic Glu-related metabolites, might be the key active component responsible for its hypoglycemic effect. Particularly, the supplement of Glx was confirmed to effectively (p < 0.05) enhance glucose consumption in hepatocytes. This provides a basis for the development of CHs as functional food.

The 2024 Nobel Prize awarded for protein structure prediction has strengthened the reliability of in silico approaches for protein and peptide research. In recent years, food-derived bioactive peptides (BAPs), which are small amino acid chains produced from food proteins, have garnered increasing interest owing to their promising health benefits. However, traditional approaches to BAPs production are often time-consuming, expensive, and unpredictable. The emergence of in silico methods has transformed BAPs research by enabling high-throughput screening and strategic utilization in food and pharmaceuticals. Molecular docking approaches have considerably expedited BAPs research by predicting the binding affinities and molecular interactions with target proteins. This review explores recent developments in computational approaches to BAPs discovery, highlighting their viability and sustainability. It provides a broad overview of advances in in silico BAPs production and molecular docking methods, delves into the appraisal of bioactivity, toxicity, and allergenicity, and discusses ligand and receptor preparation and molecular simulations. Future research should focus on improving docking algorithms, integrating multiscale modeling techniques, and incorporating high-throughput experimental screening for better validation. By addressing these challenges, the in silico techniques can play an important role in the efficient identification of novel food-derived BAPs with therapeutic potential.

We investigated the self-assembly pattern of Tilapia scale gelatin hydrolysates through Cu2+ coordination and their in vivo antioxidant properties by Cu2+-induced oxidative stress using the Caenorhabditis elegans. Two treatments (Alcalase (R), Alc; and Alcalase (R) followed by Flavourzyme (R), Alc+Flav) were used to prepare whole and <= 1 kDa hydrolysates. Upon Cu2+ coordination, the fibrillation and surface hydrophobicity of all hydrolysates decreased, suggesting a degradation of beta-sheet structures and the formation of amorphous aggregates. Rheological studies confirmed that the structural and mechanical properties of the resulting supramolecular assemblies are tunable after Cu2+ coordination. Due to the Cu2+-chelating and self-assembly properties, peptides present in the Alc hydrolysate significantly reduced endogenous ROS levels through Cu2+ coordination, thereby extending the lifespan of C. elegans. The results provide valuable insights into the influence of Cu2+ coordination on the progression of peptide self-assembly and Cu2+-induced oxidation in worms and prospects for food selfassembled peptides in biomaterial and nutraceutical applications.

Sunflower meal (SM), a byproduct of sunflower seed oil extraction, contains approximately 30-50% proteins. Recognized for its high protein content and bioavailability, it is suitable for bioactive peptides production. Yet, research exploring the potential of sunflower proteins for generating metal-chelating peptides (MCPs) is sparse. Therefore, this study aimed to evaluate SM as a protein source to produce MCPs. After protein extraction to obtain a sunflower protein isolate, single and sequential enzymatic treatments were applied to produce hydrolysates using protamex (Prot) and protamex followed by Flavourzyme (Prot + Flav), respectively. Upon sequential treatment, effectively a large number of peptide bonds were cleaved, releasing mainly small-sized peptides. Prot hydrolysates exhibited the highest Fe2+-chelating properties, inhibition of Cu2+-induced reactive oxygen species (ROS) production, and ABTS scavenging activities. Besides, sequential hydrolysis with both enzymes enhanced the inhibition of Fe3+-induced ROS production and reducing power. The Cu2+-chelating peptides present in hydrolysates were separated by using immobilized metal ion affinity chromatography (IMAC-Cu2+) and identified by LC-MS/MS analysis. MS/MS analysis of enriched Cu2+-binding peptide fractions unveiled twenty-nine potential His-containing MCPs from SMPI hydrolysate. The molecular weight of Cu2+-identified peptides ranged from 0.8 to 1.7 kDa, with the larger-sized peptides (>1 kDa) presenting the most effective bioactive properties. His, Glu, and Asp residues were crucial for metal-chelating and antioxidant properties. Due to their high potential to bind Cu2+, Fe2+, and Fe3+, SM peptides could serve as potential MCP candidates for use as food or pharmaceutical agents to prevent metal-induced oxidation and related diseases.

Background: Due to the unique structure of proline (Pro), Pro-containing peptides (PCPs) are endowed with specific conformational and physiological properties. There has been an increasing interest in the health- promoting effects of PCPs from dietary proteins. However, a comprehensive overview of the bioactivities, preparation, and bioavailability of food-derived PCPs is lacking. Scope and approach: This article provides a comprehensive discussion of recent advances in food sources, available production methods, structure-activity relationships underlying the bioactivities, and bioavailability of food-derived PCPs. Future research directions are also discussed in optimizing PCPs as health-beneficial functional food ingredients. Key findings and conclusions: Food-derived PCPs exhibit diverse bioactivities highlighting their potential human health benefits, including ACE inhibition, antioxidant effects, DPP-IV inhibition, and opioid-like effects. The role of Pro, protein source preferences, and production methods for each bioactivity are distinct. Pro-specific peptidases from the gastrointestinal tract, intestinal epithelial cells, and blood are responsible for the degradation of PCPs in vivo. Further investigation is needed to develop PCPs-specific production methods, improve the bioavailability of PCPs, and validate their bioactivity in clinical trials.

Insects are emerging as a viable alternative protein source due to shifting global consumption patterns and environmental concerns associated with meat production. Despite their nutritional benefits, insects from the orders Coleoptera, Hemiptera, and Lepidoptera are yet to be widely accepted as dietary ingredients globally. This review examines regions of the world where insects are traditionally consumed and the current trends in global consumption patterns. It presents the complex and essential nutrients inherent in the different edible insect orders, potential insect-derived products, their role in ensuring food security as well as food safety concerns. Historically, tropical and some temperate regions of Asia, Africa, North America (including Mexico), South America, and Oceania have incorporated insects into their diets. Edible insects are rich in complex and essential nutrients, including chitin, high quality amino acids, vitamins, minerals, fatty acids, phenolic compounds and flavonoids. Chitin, a dietary fibre in edible insects, offers antimicrobial, cholesterol-lowering properties and serves as an excipient in medicinal compounds. However, the varying amino acid profile of different insect species pose challenges in meeting the human dietary requirements. Nonetheless, innovative insect-derived food products such as meat substitutes and composite baked products are gaining acceptance, thereby positioning edible insects as a sustainable alternative protein source in diets.

Due to the diversity of their sequence, peptides can arrange themselves into organized nanostructures through a spontaneous and reversible process. Several strategies have proven to trigger peptide self-assembly to design biomaterials; yet, the use of coordinating Cu2+ in sunflower hydrolysates has not been exploited to date. Thus, the effect of Cu2+ coordination on peptide self-assembly of hydrolysates from sunflower meal-by-product was studied. Two enzymatic treatments (Protamex (R), Prot; and Protamex (R) followed by Flavourzyme (R), Prot + Flav) were applied to produce whole and <= 1 kDa hydrolysates. Cu2+ coordination by peptides in hydrolysates was demonstrated by Uv-vis and CD, pyrocatechol violet assay and nano-LC-MS/MS, while the self-assembly pattern of peptides upon Cu2+ coordination was revealed by ThT, ANS, DLS and TEM techniques. Upon Cu2+ coordination, tunable self-assembling peptide nanostructures endowed with improved physico-chemical properties were generated. Besides, the yield stress and G' values across most hydrolysates increased in the Peptide-Cu2+ complexes. These properties depended not only on the number of Cu2+ binding peptides but also on the binding affinity, which were different among the hydrolysates. Finally, the antioxidant assay revealed a distinct activity of the <= 1 kDa Prot containing ATCUN peptides. Indeed, similar to the activity of EDTA, this fraction extended the lifespan of C. elegans over 3 generations under Cu2+-induced oxidative stress conditions. This study represents a feasible strategy to explore Cu2+ coordination for the formation of food-derived materials via His and Cyscontaining peptides, and may provide the basis for applications of Cu2+-chelated supramolecular materials, including injectable drug delivery systems and nutraceutical products.

Sunflower (Helianthus annus L.) is one of the most important oil crops in the world. Once oil extracted, sunflower meal by-product could offer a potential alternative for various food applications due to its high protein content. Derived from food protein hydrolysates, metal-binding peptides have attracted attention as bioactive compounds to prevent metal-induced oxidation and diseases. This study aimed to investigate the Ni2+-binding ability of sunflower meal protein hydrolysates and ten peptides theoretically present in sunflower proteins using IMAC, switchSENSE®, UV-vis and CD techniques. Single and sequential enzymatic treatments were applied to produce hydrolysates using Protamex® (Prot) and Protamex followed by Flavourzyme® (Prot+Flav), respectively. MS/MS analysis of enriched Ni2+-binding peptides fractions revealed different composition of His-containing peptides among hydrolysates; however, similar to the His-containing pure peptides, the Ni2+-binding ability of all the hydrolysates was almost identical in IMAC. On the contrary, switchSENSE® studies indicated that the Ni2+-binding ability of sunflower peptides does not depend only on the presence of His residues, but also on their position along the polypeptide chain and the presence of proline, suggesting that Prot hydrolysates exhibited the highest Ni2+-binding ability. UV-vis and CD data confirmed that sunflower peptides bound onto Ni2+ through nitrogen atoms from imidazole sidechain of His residues, deprotonated amide bonds and N-terminal amino group, indicating square-planar and also octahedral geometries in the formed complexes. Finally, His-containing peptides without proline could offer a suitable strategy to design metal-binding peptides from sunflower meal by-product, with the most promising motifs being LLHVT and WLH.

Organochlorine (OC) and organophosphorus (OP) pesticides used in the storage of cowpea seeds have health implications. This study examined the effects of processing on the pesticide residues content of cowpea seeds. Ten samples of cowpea seeds were collected from randomly selected wholesale traders in a popular market in Lagos State, Nigeria. Batches of 200 g of pooled cowpea seeds were separately measured. They were washed with clean water and drained, cooked for 20 mins (WBD); soaked in water for 6 hrs and cooked for 30 mins (SBD); boiled for 10 mins (blanching), drained, rinsed with clean water and cooked to doneness (BBD). The seeds were then oven dried at 70 degrees C for 14 hrs. Another batch of cowpea seeds was dehulled (DBD). The raw and processed cowpea seeds were separately milled for determination of OC and OP pesticide residue contents using Gas Chromatography Mass Spectrophotometer (GC-MS). Proximate composition was determined using standard methods. The highest detected levels of OC and OP residues in raw cowpea seeds were beta-benzene hydrochloride (Beta-BHC) (68.87 mu g/kg) and azimosmethyl (760 mu g/kg), respectively. Beta-BHC content decreased most by 46 % when blanched and increased by 7 % in washed seeds. Chlorothanonil contents reduced with all the processes but most when soaked (85 %) and dehulled (82.6 %) before cooking whereas heptachlor epoxide increased in blanched seeds. The treatments had no effect on organophosphorus pesticide residues except for phosphamidon, chlorpyrifos and parathion-methyl, which reduced by 100 %, 27 % and 26 %, respectively when blanched. The treatments had varying effects on the proximate composition of the cowpea seeds. Taken together, the effects of the different processing methods were residue-specific, but dehulling and blanching were more effective compared to washing and soaking, thus providing low-cost approaches for consumers to eliminate or reduce the pesticide levels in cowpea-based diets.

Ovalbumin-derived peptide, VLVNAIVFKGL, demonstrated self-assembling and gelation properties. However, the extent of self-assembly via solvent-switching and the bioactive potential of the ordered peptide aggregates is unknown. In silico analysis using AGGRESCAN, TANGO, ANuPP, and GAP predicted a high propensity to self-assemble into amyloid-like aggregates. Thioflavin T fluorescence assay confirmed enhanced self-assembly at low solvent concentrations (0.03-5% DMSO) and increasing peptide concentration (4-400 mu M). Transmission electron microscopy showed enhanced formation of interconnected fibrillar networks at 400 mu M. Mechanical properties assessed via rheology confirmed the hydrogelation of the fibrillar networks with high fibrillar stability in simulated gastrointestinal fluids. Oxidative stress assays using Caenorhabditis elegans showed a 21.48 +/- 3.37% reduction in juglone-induced reactive oxygen species production by the hydrogel. In silico analysis further predicted the cell-penetrating and nontoxic characteristics of the peptide, highlighting the potential biocompatibility. Taken together, these findings support the development of VLVNAIVFKGL as an antioxidant peptide hydrogel for edible applications.

Pea protein fractions (albumin, glutelin, and globulin) were investigated for the influence of their interaction with curcumin on in vitro gastric protein digestibility. Dynamic light scattering analysis showed a decreased average particle size of the protein (0.25 mg/mL)/curcumin (2-100 mu M) combinations. Turbidity and surface hydrophobicity analyses suggested the protein/curcumin complex formation via noncovalent interactions. Transmission electron microscopy revealed the formation of spherical nanocomplexes for albumin and globulin fractions and sheet-like structures for glutelin fraction with curcumin. Furthermore, curcumin did not alter the protein profiles, but at high concentration (100 mu M), it differentially decreased the degree of hydrolysis of albumin, glutelin, and globulin by 76.6, 100, and 58.6%, respectively, indicating that the nature of the nanocomplexation hindered pepsin accessibility for protein hydrolysis. Therefore, this study enhances our understanding of how interactions between biomolecules in nanodelivery complexes and nutraceutical formulations influence the nutritional quality of plant-based proteins.

Oxidative stress contributes to aging and degenerative diseases. Hempseed-added kombucha (HK) contains higher levels of antioxidants, phenolics, and proteins than traditional kombucha (CK), suggesting a greater potential to combat oxidative stress. The aim of this study was to evaluate the effect of HK on the increase in resistance to oxidative stress using the in vivo Caenorhabditis elegans biological model. Antioxidant capacity (AC) was measured with DPPH+ and ABTS+ assays, while oxidative stress resistance was assessed via survival and ROS production in C. elegans. The DPPH+ assay showed AC of 0.119 mg Trolox equivalent (TE)/mL for CK and 0.163 mg TE/mL for HK. The ABTS+ assay showed AC of 0.101 mg TE/mL for CK and 0.136 mg TE/mL for HK, with significant differences (p < 0.05). Juglone-induced oxidative damage was reduced by 10-15% with CK and 30-35% with HK. HK enhanced survival and reduced ROS levels in nematodes. These findings highlight HK's potential as a superior functional beverage for dietary interventions against oxidative stress.

Garlic is a popular food spice with diverse and well-established medicinal properties. Many research interests have been directed toward the biological activities of the phytochemical constituents of garlic. However, prospects of its bioactive proteins and peptides have been understudied to date. With the advances in food proteomics/peptide research, a review of studies on garlic bioactive proteins and peptides, especially on their nature, extraction, and biological activities, is timely. Garlic has been reported to express several proteins, endogenous and protein-derived peptides with interesting bioactivities, including antioxidant, anti-inflammatory, antibacterial, antifungal, anti-proliferative, antiviral, anti-hypertensive and immunomodulatory activities, suggesting their therapeutic and pharmacological potentials. Compared to legumes, the low protein contents of garlic bulbs and their low stability are possible limitations that would hinder future applications. We suggest adopting heterologous expression systems for peptide overproduction and stability enhancement. Therefore, we recommend increased scientific interest in the bioactive peptides of garlic and other spice plants.

Abstract The normal immune response to infection requires a well-regulated mechanism of leukocyte activation and recruitment, a process generally termed inflammation. Dysregulation of this inflammatory response is a major problem in modern medicine and is associated with several disease conditions including autoimmune diseases, cancer and even COVID-19. Food-derived peptides with anti-inflammatory properties have gained popularity due to their availability in the daily diet and limited side effects. Previous reports have shown that the potato protein patatin has anti-inflammatory property. However, the sequence of amino acids in patatin that is critical for anti-inflammatory activity is not well established. In this work, we investigated the ability of the potato protein-derived peptide DIKTNKPVIF to down-regulate the inflammatory response of monocyte-derived macrophages (MDMs) activated with lipopolysaccharide (LPS). We found that DIKTNKPVIF inhibited the inflammatory response of MDMs to LPS as evidenced by decreased production of pro-inflammatory cytokines. Importantly, using computational and experimental screening techniques, we identified TNKPVI as the bioaccessible and biostable pharmacophore necessary for the activity of DIKTNKPVIF. Our results highlight the potential of potato-derived bioactive peptides to regulate the inflammatory response.

Food-derived bioactive compounds mimicking the effects of incretin therapies offer promising opportunities for combination therapies with functional foods, where food matrix interactions, gastrointestinal enzyme activity, and in situ bioactivity should be key considerations. In this study, green lentils were solid-state fermented with Lactiplantibacillus plantarum ATCC8014, in vitro digested and exposed to brush border enzymes of a Caco-2 cell monolayer. Intestinal absorption of peptides and DPP-IV inhibitory activity were then investigated. LC-MS/MS profiles showed that peptides mainly originated from parental proteins of the vicilin, convicilin and legumin families. Fermentation led to the formation of more hydrophobic peptides when compared to the unfermented flour and up to 33.6% of them were transported to the basolateral side of a Caco-2 cell monolayer. Peptides with more than 22 amino acids and with a mass greater than 2000 Da were minimally transported. 73 peptides were uniquely identified in the basolateral fraction suggesting that they resulted from the activity of the brush border enzymes. The DPP-IV activity of Caco-2 cells grown as a polarized monolayer was decreased by 37.3% when exposed to in vitro digested 72 h-fermented lentil flour and 10% when exposed to the unfermented one. Inhibition of DPP-IV in the basolateral fluids was improved in a dose-dependent manner and reached 7.9% when 500 mg mL-1 of in vitro digested 72 h fermented lentil flour was used. Glucose absorption and uptake were minimally affected, suggesting that the previously observed hypoglycemic properties of lentils are likely due to activity on DPP-IV rather than on the inhibition of glucose absorption.

Bioactive peptides and protein hydrolysates have gained considerable attention in the food industry and functional food markets due to their diverse health effects, including antioxidant, antihypertensive, and antidiabetic properties. This study aimed to produce combined soy and corn protein hydrolysates using Alcalase (Al), modification of Al-hydrolysates through sequential hydrolysis using Flavourzyme (Al-FL), cross-linking of Al-hydrolysates using microbial transglutaminase (MTGase) (Al-TG), and fractionation of Al-hydrolysates by ultrafiltration (UF) with molecular weight (MW) cut-off of 100 (Al-F4), 30 (Al-F3), 10 (Al-F2), and 2 kDa (Al-F1). Notably, the < 2 kDa fraction (Al-F1) showcased exceptional biological activities, including antioxidant (81.54% DPPH, 98.02% ABTS), antihypertensive (95.45%), and antidiabetic effects (44.72% alpha-glucosidase, 77.52% alpha-amylase), linked to its high hydrophobic amino acid content and low molecular weights (111 and 263 Da). Conversely, the higher molecular weight fraction (Al-TG) excelled in emulsion and foam stability, attributed to its balanced amino acid profile and larger peptides (1385-7057 Da). Our findings reveal that specific protein hydrolysate fractions, particularly Al-F1 and Al-TG, are promising for applications in food and pharmaceutical formulations due to their enhanced biological and functional properties.

This study focused on the enzymatic characteristics, with regard to primary specificity, secondary specificity, and hydrolysis ability of five proteases (Alcalase, Protamex, papain, Flavourzyme, and ProtexA), towards the release of dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides from bovine casein. The secondary specificity of the five proteases, especially the release capability for Xaa-Pro-type peptide played a determining role in the release of DPP-IV inhibitory peptides from bovine casein. Moreover, protease combinations, chosen based on their Xaa-Pro-type peptide release abilities, resulted in superior DPP-IV inhibitory activity compared to other combinations. Particularly, the hydrolysate with the highest DPP-IV inhibitory activity (IC50 value of 0.45 ± 0.07 mg/mL) was obtained by the combination hydrolysis of ProtexA and papain, achieving a 74.63% ± 1.62% (peak area) release of Xaa-Pro-type peptide, and a significant improving glucose tolerance in mice (33.42% ± 1.68% reduction of blood glucose AUC compared with control mice). The mechanistic insights revealed that papain efficiently released long Xaa-Pro-type peptides in the early hydrolysis stage, and subsequently, the synergistic effect of papain and ProtexA led to an accelerated and extensive release of short Xaa-Pro-type peptides. These findings provide valuable insight into enzymatic processes for generating DPP-IV inhibiting peptides from casein.

Type 2 diabetes development has been associated with islet amyloid polypeptide (IAPP) fibrillation. IAPP fibrils have various deleterious effects, such as oxidative stress and disruption of cellular membrane integrity, resulting in pancreatic beta-cell toxicity. Rutin, a plant polyphenol, possesses promising cytoprotective effects as a fibrillation inhibitor. Similarly, bioactive peptides have been identified as potential inhibitors to IAPP fibrillation. In this study, the effect of peptide/polyphenol mixtures consisting of rutin and each peptide, TNGQ, MANT, and YMSV, on anti-fibrillation activity and cellular response was elucidated. Results indicated a 54.7-75.1 % decrease in thioflavin T fluorescence, confirming anti-fibrillation activity. The combination decreased the average particle diameters of IAPP more than the single inhibitors, suggesting a combined effect of peptide/rutin mixtures in enhancing anti-fibrillation activity. IAPP fibrillation-induced rat insulinoma RIN-m cell death was minimized in the presence of the peptide/rutin mixture, but the activity was lower relative to rutin alone, suggesting a nonadditive effect of the mixtures. Transmission electron microscopy showed a near-complete inhibition of IAPP fibrillation by TNGQ/rutin mixtures, which translated to a decreased production of membrane-bound IAPP oligomers in RIN-m cells based on immunofluorescence staining. Additionally, TNGQ/rutin mixtures significantly decreased reactive oxygen species production by 30 %, higher than the effects of single inhibitors, but no effect was observed on glucose-stimulated insulin secretion. The results demonstrate the potential of multifunctional compounds as dual inhibitor systems in controlling IAPP fibrillation and provide insight into the implications of peptide/polyphenol mixtures towards the rational development of novel anti-diabetic nutraceutical combinations.