Structural, functional and antioxidant properties of Lentinus edodes protein hydrolysates prepared by five enzymes

Effects of high hydrostatic pressure processing on the physicochemical properties, functional characteristics, and antioxidant activity of silkworm pupae protein

With the rising demand for sustainable proteins, edible insects such as silkworm pupae are gaining recognition for their high-quality protein and essential nutrients. Advanced technologies like high hydrostatic pressure (HHP) processing have the potential to enhance the functional properties of insect proteins. This study investigated the application of HHP to silkworm pupa protein, focusing on its effects on physicochemical properties, functional characteristics, and bioactivity. HHP treatments at 400 and 600 MPa significantly enhanced emulsifying and foaming capacities, as well as antioxidant activity. Furthermore, HHP-assisted extraction facilitated protein unfolding and increased the exposure of hydrophobic groups on the protein surface, which likely contributed to improvements in protein solubility and antioxidant function. These findings provide valuable insights into the potential of HHP to enhance the quality of edible insect proteins for food applications.

Exploring alternative sources of protein in food: Trends in nutrient and functional features

Proteins are essential biomolecules that perform critical roles in various biological processes, such as building and repairing tissues, transporting substances, signaling hormones, and providing protection. Traditional methods of meeting human protein needs, primarily through animal farming, have significant negative impacts on the environment. In many low-income countries, protein requirements often go unmet due to the high costs associated with animal farming. Additionally, the rise in food allergies has become a serious health concern, highlighting the need for alternative protein sources that cater to individuals sensitive to traditional proteins. As the world's population is projected to reach around nine billion by 2050, there are growing concerns that conventional protein sources may not be sufficient to meet the increasing demand. This situation has led to heightened interest in alternative protein sources that can fulfill nutritional needs without the drawbacks associated with traditional meat consumption. This systematic review aims to explore non-traditional dietary protein sources, focusing on their nutritional and some techno-functional characteristics reported. These sources may include a variety of options such as animals (both vertebrates and invertebrates), plants (like leaves, seeds, and legumes), algae, fungi, and by-products from the food industry.

Ultrasonic replacement of natural aging: Potential strategies for improving the color, antioxidant activity, and volatile compound profile of astragalus mead

The growing demand for natural and functional beverages has driven research aimed at improving the quality of herbal meads. This study investigates the use of non-thermal processing methods, ultrasonic, microwave, and high hydrostatic pressure processing, as alternatives to traditional natural aging for improving the physicochemical properties, antioxidant activity, color stability, and volatile compound profile of astragalus mead. Response surface methodology was employed to optimize fermentation conditions, which yielded the highest flavonoid content and sensory quality at an impregnation time of 12 h, an impregnation temperature of 10 °C, and a fermentation temperature of 20 °C. Among the processing methods evaluated (natural aging, ultrasound, microwave irradiation, and high hydrostatic pressure), ultrasound treatment resulted in the most significant improvements. Specifically, it increased total phenol content by 7.22 %, total flavonoid content by 9.41 %, and antioxidant capacity by 65.43 %. Volatile compound analysis also revealed a 191.30 % increase in ester content, significantly enhancing floral and fruity notes. Sensory analysis using quantitative descriptive analysis, partial least squares discriminant analysis, and weighted gene co-expression network analysis confirmed the efficacy of ultrasound, with ethyl caprylate identified as a key aroma contributor. These findings suggest that ultrasound is an effective non-thermal processing technique for improving the aging process and overall quality of astragalus mead. This study provides valuable insights for the industrial application of non-thermal processing technologies in astragalus mead production.

High-intensity ultrasound treatment of shiitake mushroom protein isolate: effects on physicochemical, structural properties, and functional performance

BACKGROUND

With increasing consumer demand for healthy and sustainable food, plant proteins have been used widely in meat substitutes, dairy alternatives, and functional foods. However, in comparison with animal proteins, plant proteins often exhibit weaker functional properties, such as solubility, emulsifying, and gelation, which limit their application in food processing. The aim of this study was to investigate the effects of high-intensity ultrasound treatments (HIUTs) on the physicochemical properties, structural characteristics, emulsifying properties, and antioxidant capacity of shiitake mushroom protein isolate (SMPI). This study investigates how HIUTs affect SMPI. It also provides insights into potential applications within the food industry.

RESULTS

When treated with a 300 W intensity ultrasound, SMPI exhibited higher solubility, water-holding capacity (WHC), oil-holding capacity (OHC), and antioxidant activity in comparison with the control (0 W). These results indicate that HIUT can enhance the functional properties of SMPI significantly. The molecular structure of SMPI after ultrasound treatment also underwent significant changes, suggesting that the treatment affects not only the physical properties but also the spatial conformation of SMPI. The concentration of free sulfhydryl (-FSH) group concentrations increased from 3.615 ± 0.080 μmol g-1 to 13.020 ± 0.061 μmol g-1, and the emulsifying ability index (EAI) significant increased, indicating that a significant change produced in the tertiary structure of SMPI.

CONCLUSION

The findings suggest that ultrasonic treatment can alter the physicochemical and functional attributes of SMPI significantly, increasing its potential for use within the food industry. © 2024 Society of Chemical Industry.

Enhancement on the solubility of polyploid and diploid rice proteins by enzymatic hydrolysis: From structural and functional characteristics of rice protein hydrolysates

Polyploid rice protein (PRP) has the advantage of high nutritional value, but its functional properties are minimal due to its poor solubility. This work aims to improve the solubility of PRP through enzymatic hydrolysis and assess the effect of hydrolysis time (5-330 min) and protease type (Alcalase, Neutrase, and Trypsin) on the structural, functional, and antioxidant properties of PRP hydrolysates (PRPHs). Compared to PRP, PRPHs exhibited significantly decreased free sulfhydryl content and surface hydrophobicity and improved structural flexibility, regardless of the protease used. With increasing time, the nitrogen solubility index of the hydrolysates increased by 25.01 %, which was attributed to the reduction in molecular weight (< 15 kDa). The highest emulsifying activity (48.81 m2/g) and hydroxyl radical scavenging activity (IC50 of 5.49 mg/mL) were observed from Neutrase hydrolysates at 210 min and 330 min, respectively. Trypsin hydrolysate at 210 min demonstrated the lowest IC50 (0.17 mg/mL) in ABTS+. Moreover, compared to diploid rice protein hydrolysates (DRPHs) obtained under the same conditions, PRPHs by all proteases exhibited superior functional and antioxidant properties and richer amino acid content. This study showed the potential of PRPHs applied to functional foods with favorable functional and antioxidant properties.

A novel iron fortifier prepared through quinoa protein peptides hydrolyzed with different proteases

Iron deficiency is a widespread global issue that leads to nutritional disorders and iron deficiency anemia (IDA). In this study, quinoa protein peptide (QPP) was selected to design a novel iron supplement, quinoa protein peptide‑iron chelate (QPP-Fe). Notably, QPP with a molecular weight of <2000 Da, prepared using Alcalase, exhibited the highest iron chelation ratio of 79.2 ± 0.36 mg/g. Furthermore, FTIR, UV-Vis, CD, and fluorescence spectroscopy results indicated that the addition of Fe2+ significantly altered the secondary structure of QPP. This alteration was primarily attributed to the interaction of Fe2+ with carboxyl, amino, and imidazole groups. Moreover, we observed that the QPP-Fe form compact spherical structures, leading to reduced and much more uniform particle sizes. The molecular docking results revealed that Fe2+ formed ligand bonds with Glu, His, Ala, and Gly through electrostatic interactions. Then a pocket structure that wrapped Fe2+ around the peptide was formed, which changed the peptide from a free and disordered state to a more stable state. These results can provide a reference for the development of iron-fortified functional foods.

Enhancement of foaming performance of hempseed protein by limited enzymatic hydrolysis: From the viewpoint of the structural and interfacial rheological attributes

Effects of limited enzymolysis by Alcalase and Protamex on the foaming performance of hempseed protein (HPI) and its correlation with structural and interfacial rheological characteristics were investigated. Proteolysis induced a conformational shift from α-helix and β-sheet to random coil, indicating enhanced molecular flexibility. The surface hydrophobicity of Alcalase hydrolysates encountered an initial increase (5 min) followed by a sharp drop with prolonged hydrolysis, whereas Protamex showed minimal effects. Both proteases reduced total sulfhydryl content and caused a redshift in intrinsic fluorescence, particularly Alcalase. The specific cleavage pattern of Alcalase generated peptides with pronouncedly higher solubility (up to 47.0 %) relative to Protamex. The flexible conformation and increased solubility induced by moderate proteolysis, notably with Alcalase, facilitated viscoelastic interfacial membranes with consolidated intermolecular interactions, consequently contributing to more homogeneous and smaller bubble structures. Optimal foaming capacity (95.0 %) and foam stability (90.9 %) were achieved with Alcalase for 20 min and 5 min, respectively.

Impact of High Hydrostatic Pressure on the Physicochemical Characteristics, Functional Properties, Structure, and Bioactivities of Tenebrio molitor Protein

This study aimed to explore the influence of high hydrostatic pressure (HHP) treatment on the structure, functional characteristics, and bioactivities of Tenebrio molitor protein. The results showed that HHP induced dissociation of T. molitor protein, exposing hydrophobic groups and reducing particle size, which in turn reduced turbidity. Additionally, 600 MPa treatment significantly reduced the foaming stability and emulsifying activity of T. molitor protein. Treatments at 200 MPa and 400 MPa significantly reduced emulsion stability, whereas 400 MPa treatment significantly increased oil retention. HHP treatment also altered the secondary and tertiary structures of T. molitor protein, as demonstrated by circular dichroism and fluorescence spectra. Furthermore, HHP treatment significantly affected the antibacterial and antioxidant activities of T. molitor protein. This study provides a theoretical framework for using HHP to modify T. molitor protein.

Enhancing the physical and oxidative stability of hempseed protein emulsion via comparative enzymolysis with different proteases: Interfacial properties of the adsorption layer

Effects of enzymolysis by seven proteases (Alcalase, Bromelain, Flavourzyme, Papain, Pepsin, Protamex, and Trypsin) with distinct cleavage specificities on the emulsification performance of hempseed protein (HPI) and its correlation with the structural and interfacial characteristics were explored in this study. Upon enzymolysis, a remarkable decrease in α-helix and β-turn was observed in resultant hydrolysates (HPH), accompanied by a rise in β-sheet and random coil, notably by Alcalase, Bromelain, Papain, and Trypsin. Overall, proteolysis led to noticeable reductions in surface hydrophobicity and total sulfhydryls as well as a redshift in intrinsic fluorescence, with Papain showing the most pronounced effects, possibly due to its higher hydrolysis degree (4.00 %). Interestingly, among the seven HPHs, Papain-HPH with the highest solubility (67.4 %) and smallest molecular weight exhibited compromised interfacial activity, lowest emulsifying activity (EAI, 1.67 m2/g), and highest creaming index (CI, 64 %). Contrastively, Trypsin hydrolysis significantly improved the interfacial activity, albeit causing a notable decrease in interfacial viscoelasticity of the absorbed layers. Consequently, Trypsin yielded the best EAI (10.5 m2/g) and emulsion stability (CI, 4 %); yet, the smallest emulsion droplets with homogeneous distribution and high apparent viscosity were spotted. Additionally, the oxidative stability of emulsions was conspicuously enhanced, contingent upon the antioxidative capacity of HPHs.

Structure, antioxidant activity, and neuroprotective effect of black soybean (Glycine max (L.) merr.) protein hydrolysates

The potential biological properties of protein hydrolysates have generated considerable research interest. This study was to hydrolyze black soybean protein (BSP) using five different commercial enzymes, and elucidate the influence of these enzymes on the structure and biological activities of the resulting hydrolysates. Enzymatic treatment changed secondary and tertiary structures of BSP, decreased particle size, α-helix and β-sheet. Alcalase hydrolysate had the highest hydrolytic degree (29.84 %), absolute zeta potential (38.43 mV), the smallest particle (149.87 nm) and molecular weight (<3 kDa). In silico revealed alcalase hydrolysate had the strongest antioxidant potential. This finding was further validated through the lowest IC50 (mg/mL) in DPPH (2.67), ABTS (0.82), Fe2+ chelating (1.33) and·OH (1.12). Moreover, cellular antioxidant assays showed alcalase hydrolysate had the strongest cytoprotective effects on H2O2-induced PC12 cells. These results suggest BSPEHs, especially those prepared by alcalase, have potential as bioactive ingredients for nutrition, healthcare and food industry.

Physicochemical and stability analysis of mung bean protein hydrolysates with lipid peroxidation inhibition

This study investigated mung bean protein hydrolysates (MBPH) produced using neutral protease, examining their physicochemical properties, stability, and lipid peroxidation inhibition capabilities. The research revealed that MBPH molecular weight ranged from 17 to 26 kDa and perform various functions, including catalytic, nutrient storage, and binding. Stability assessments showed that MBPH are stable at 45 °C and pH of 7.5 but are light-sensitive and unstable in solution or when combined with sugars. Additionally, increased concentrations of digestive enzymes reduce MBPH stability. Antioxidant tests in vitro and in Caenorhabditis elegans confirmed MBPH's ability to neutralizing radicals, enhance antioxidant enzyme activities, and reduce lipid peroxidation, thereby protecting against oxidative damage. Furthermore, in vivo experiments showed that MBPH extend the lifespan of worms and reduced their body lipid content, indicating potential benefits in mitigating cholesterol-related damage. This research demonstrates the potential of MBPH in inhibiting lipid peroxidation.

Spray-Dried Wheat Gluten Protein Hydrolysate Microcapsules: Physicochemical Properties, Retention of Antioxidant Capability, and Release Behavior Under Simulated Gastrointestinal Digestion Conditions

Wheat gluten is a by-product of the wheat starch industry, rich in bioactive peptides. Spray drying is an effective method for improving the stability of bioactive compounds. So, the aim of this study was to produce gluten hydrolysate by different proteases (alcalase, pancreatin, and trypsin) at different times (40-200 min). The hydrolysate with the strongest antioxidant potential (produced by pancreatin after 200 min of hydrolysis) was encapsulated by spray drying. The effect of wall material's type (maltodextrin, potato starch, and their combination at different ratios) on the encapsulation efficiency, physicochemical properties (moisture content, solubility, water activity, tapped and bulk density, and hygroscopicity), release behavior under simulated gastrointestinal digestion conditions, and morphology of microcapsules were evaluated. The microcapsules produced by maltodextrin and potato starch at a 30:70 ratio possessed the highest water activity (0.36), encapsulation efficiency (85.79%), and moisture content (8.2%). An increase in maltodextrin concentration increased the solubility, bulk, and tapped density. SEM images showed that microparticles were spherical with wrinkled surfaces. The microcapsules showed higher stability than free gluten hydrolysate. The combination of maltodextrin and potato starch at a 30:70 ratio could control the release of gluten hydrolysate under simulated gastrointestinal conditions. As a result, the use of maltodextrin and potato starch carriers at a 30:70 ratio in spray drying could effectively protect the bioactive properties of gluten hydrolysate and control its release.

Advancing protein hydrolysis and phytosterol encapsulation: Emerging trends and innovations in protein-based microencapsulation techniques - A comprehensive review

Phytosterols represent a diverse and complex category of lipophilic bioactive compounds, exhibiting excellent pro-healthy properties. However, their consumption in daily diets is insufficient, and their application in food production is hindered by challenges such as low water solubility, high reactivity, and rapid degradation. The adoption of different protein or their structural modification as hydrolysates as wall material into microencapsulation techniques can be associated with improved solubility, enhanced bioaccessibility, increased bioavailability, and an extension of shelf life. This contribution provides an overview of advancements in modifying functional properties through various protein isolation methods and structural changes resulting from enzymatic hydrolysis. Additionally, the paper considers the state of the art in the utilization of various techniques and the composition of wall material in the encapsulation of phytosterols and other common lipophilic phytochemicals incorporated into delivery systems. Protein isolates obtained through novel methods of extraction may be characterized by an enhancement of their functional properties, which is crucial for the microencapsulation process. It entails not only recognizing their role as protective barriers for core materials against environmental conditions but also acknowledging their potential health-promoting attributes. These attributes encompass antioxidant properties and enhanced functional characteristics compared to native proteins. Moreover, the exploration of protein hydrolysates as versatile wall materials holds significant promise. These hydrolysates offer exceptional protective features for core materials, extending beyond mere environmental shielding. The envisioned impact extends beyond conventional delivery systems, offering transformative potential for the future of drug delivery and nutraceutical formulations.

Physicochemical properties, antioxidant and antidiabetic activities of different hydrolysates of goat milk protein

There is growing interest in the origin, preparation, and application of bioactive peptides. This study investigated the impact of 6 enzymes on the structural, physicochemical properties, antioxidant activities, and antidiabetic potential of defatted fresh goat milk. Structural and functional changes resulting from enzymatic hydrolysis were assessed using gel electrophoresis, laser particle size analysis, multi-spectroscopy, and evaluations of foaming and emulsification properties. Antioxidant capacity was determined through free radical scavenging, Fe2+ chelation, and reducing ability experiments. Additionally, the inhibitory effects of the hydrolysates on α-glucosidase and α-amylase were measured to evaluate antidiabetic activity. Results showed that enzymatic hydrolysis disrupted the spatial structure of goat milk protein and reduced its molecular weight. Papain hydrolysate exhibited the highest degree of hydrolysis (32.87 ± 0.11%) and smallest particle size (294.75 ± 3.33 nm), followed by alcalase hydrolysate (29.12 ± 0.09%, 302.03 ± 7.28 nm). Alcalase hydrolysate showed the best foaming properties, while papain hydrolysate demonstrated the strongest DPPH and hydroxyl radical scavenging activity, Fe2+ chelation, and antidiabetic potential. These findings provide solid theoretical basis for utilizing defatted goat milk as functional ingredients or excipients in the food, medical, and cosmetic industries.

Screening, separation and identification of metal-chelating peptides for nutritional, cosmetics and pharmaceutical applications

Metal-chelating peptides, which form metal-peptide coordination complexes with various metal ions, can be used as biofunctional ingredients notably to enhance human health and prevent diseases. This review aims to discuss recent insights into food-derived metal-chelating peptides, the strategies set up for their discovery, their study, and identification. After understanding the overall properties of metal-chelating peptides, their production from food-derived protein sources and their potential applications will be discussed, particularly in nutritional, cosmetics and pharmaceutical fields. In addition, the review provides an overview of the last decades of progress in discovering food-derived metal-chelating peptides, addressing several screening, separation and identification methodologies. Furthermore, it emphasizes the methods used to assess peptide-metal interaction, allowing for better understanding of chemical and thermodynamic parameters associated with the formation of peptide-metal coordination complexes, as well as the specific amino acid residues that play important roles in the metal ion coordination.

Multi-omics in food safety and authenticity in terms of food components

One of the main goals of food science is to ensure the high quality and safety of food. The inspection technology for known hazards has matured, and the identification of unknown and potential food safety hazards, as well as the identification of their composition and origin, is a challenge faced by food safety. Food safety and authenticity require multi-omics methods to support the implementation of qualitative discrimination to precise quantitative analysis, from targeted screening to non-target detection, and from multi component to full component analysis to address these challenges. The present review aims to provide characterizations, advantages, the latest progress, and prospects of using omics (including genomics, proteomics, and metabonomics) in food safety and authenticity. Multi omics strategies used to detect and verify different standard biomarkers of food will contribute to understanding the basic relationship between raw materials, processing, foods, nutrition, food safety, and human health.

Multifunctional apple seed protein hydrolysates: Impact of enzymolysis on the biochemical, techno-functional and in vitro α-glucosidase, pancreatic lipase and angiotensin-converting enzyme inhibition activities

The work was designed to assess the amelioration effect of papain hydrolysis on the biochemical, techno-functional, and biological properties of apple seed protein isolate (API) after 0-90 min of hydrolysis. Hydrolysis significantly enhanced the nutritional value (protein content ˃ 90 %) while decreasing the average particle size. With increasing hydrolysis time, FTIR analysis revealed a transition from α-helix to β-turn structure, indicating the unfolding of protein structure. This structural alteration positively influenced the functional characteristics, with samples hydrolyzed for 90 min exhibiting excellent solubility, higher water and oil absorption capacity, foaming capacity, and increased emulsifying activity index. Moreover, samples hydrolyzed for 90 min displayed the highest α-glucosidase (29.62-57.43 %), pancreatic lipase inhibition (12.87-31.08 %), and ACE inhibition (25.32-62.70 %) activity. Interestingly, the inhibiting ability of protein hydrolysates against α-glucosidase and ACE was more effective than pancreatic lipase, suggesting their usefulness as a functional ingredient, particularly in type II diabetes and hypertension management.

Assessment of cell wall degrading enzymes by molecular docking and dynamics simulations: Effects of novel infrared treatment

Cell wall-degrading enzymes' activities under infrared treatment are vital for peeling; it is critical to elucidate the mechanisms of the novel infrared peeling in relation to its impact on cell wall-degrading enzymes. In this study, the activities, and gene expressions of eight degrading enzymes closely related to pectin, cellulose and hemicellulose were determined. The most influential enzyme was selected from them, and then the mechanism of its changes was revealed by molecular dynamics simulation and molecular docking. The results demonstrated that infrared had the most significant effect on β-glucosidase among the tested enzymes (increased activity and up-regulated gene expression of 195.65 % and 7.08, respectively). It is suggested infrared crucially promotes cell wall degradation by affecting β-glucosidase. After infrared treatment, β-glucosidase's structure moderately transformed to a more open one and became flexible, increasing the affinity between β-glucosidase and substrate (increasing 75 % H-bonds and shortening 15.89 % average length), thereby improving β-glucosidase's activity. It contributed to cell wall degradation. The conclusion is that the effect of infrared on the activity, gene expression and molecular structure of β-glucosidase causes damage to the peel, thus broadening the applicability of the new infrared dry-peeling technique, which has the potential to replace traditional wet-peeling methods.