Effects of combined high pressure and enzymatic treatments on physicochemical and antioxidant properties of peanut proteins

Hydrolysates with emulsifying properties prepared from protein wastes using microbial protease

Plant-based protein hydrolysates have found applications in food industry for emulsification, foaming, and increasing shelf life of food products. The objective of this study is to isolate protease-secreting bacteria hydrolyzing protein waste, and subjecting the resultant hydrolysates for the characterization for application in the food industry. Peanut cake hydrolysates were prepared using proteases from two microorganisms selected for the purpose, viz., Aneurinibacillus migulanus, VITPM11 and Aneurinibacillus aneurinilyticus, VITPS07. The cleavage specificity of the proteases from VITPM11 and VITPS07 were found to be like plasmin and elastase respectively. The cleaving sites of proteases for peanut proteins were predicted using expasy tool. The protease of VITPM11 had maximal activity of 325.8 ± 0.1 U/mL in peanut-cake media. The degree of hydrolysis (32.03 ± 0.89%), solubility (88.5 ± 1.18%), emulsion stability index (89.76 ± 2.80) and foaming stability (68.67 ± 1.53%) properties of VITPM11 protease correlated well with results from bioinformatic studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01490-z.

Milk Antiviral Proteins and Derived Peptides against Zoonoses

Milk is renowned for its nutritional richness but also serves as a remarkable reservoir of bioactive compounds, particularly milk proteins and their derived peptides. Recent studies have showcased several robust antiviral activities of these proteins, evidencing promising potential within zoonotic viral diseases. While several publications focus on milk's bioactivities, antiviral peptides remain largely neglected in reviews. This knowledge is critical for identifying novel research directions and analyzing potential nutraceuticals within the One Health context. Our review aims to gather the existing scientific information on milk-derived antiviral proteins and peptides against several zoonotic viral diseases, and their possible mechanisms. Overall, in-depth research has increasingly revealed them as a promising and novel strategy against viruses, principally for those constituting a plausible pandemic threat. The underlying mechanisms of the bioactivity of milk's proteins include inhibiting viral entry and attachment to the host cells, blocking replication, or even viral inactivation via peptide-membrane interactions. Their marked versatility and effectiveness stand out compared to other antiviral peptides and can support future research and development in the post-COVID-19 era. Overall, our review helps to emphasize the importance of potentially effective milk-derived peptides, and their significance for veterinary and human medicines, along with the pharmaceutical, nutraceutical, and dairy industry.

Gamma radiation vs high pressure pretreatment on physicochemical characteristics of rice bran hydrolysate

This study investigated the effect of using gamma radiation and high-pressure processing as pretreatment, to consider the structural and amino acid composition changes in rice bran hydrolysate (RBH). The extraction yield and degree of hydrolysis of the irradiated sample were greater than those of the pressurized and control samples, which radiation at 10 kGy gave 31 % yield. Protein content of the control was the highest at 36.1 %, with 32.4 % in pressurized sample at 500 MPa. Control had the highest concentration of total and branched-chain amino acids, with a value of 25,834 mg/100g. Before and after extraction, the microstructure changed visibly and protein agglomeration can be significantly induced by applying a high-pressure. Therefore, this study showed the potential of using both pretreatment methods prior to enzymolysis extraction, with radiation producing more extract. High-pressure produced more protein content, but neither method produced any difference in amino acid content.

Purification, Identification and Molecular Docking of Novel Antioxidant Peptides from Walnut (Juglans regia L.) Protein Hydrolysates

Walnut protein isolate (WPI) was hydrolyzed using Alcalase for 0, 30, 60, 90, 120 and 150 min to investigate the effect of different hydrolysis times on the structure and antioxidant properties of walnut proteins. The identified peptides HADMVFY, NHCQYYL, NLFHKRP and PSYQPTP were used to investigate the structure-activity relationship by using LC-MS/MS and molecular docking. The kinetic equations DH = 3.72ln [1 + (6.68 E₀/S₀ + 0.08) t] were developed and validated to explore the mechanism of WIP hydrolysis by Alcalase. Structural characteristics showed that the UV fluorescence intensity and endogenous fluorescence intensity of the hydrolysates were significantly higher than those of the control. FTIR results suggested that the secondary structure gradually shifted from an ordered to a disordered structure. Enzymatic hydrolysis containing much smaller molecule peptides than WPI was observed by molecular weight distribution. In vitro, an antioxidant test indicated that Alcalase protease hydrolysis at 120 min showed more potent antioxidant activity than hydrolysates at other hydrolysis times. In addition, four new antioxidant peptides were identified by LC-MS/MS. Molecular docking indicated that these peptides could interact with ABTS through interactions such as hydrogen bonding and hydrophobic interactions. Thus, WPI hydrolysates could be used as potential antioxidants in the food and pharmaceutical industries.

Response Surface Modeling and Optimization of Enzymolysis Parameters for the In Vitro Antidiabetic Activities of Peanut Protein Hydrolysates Prepared Using Two Proteases

Optimization of the enzymolysis process for preparing peanut protein hydrolysates using alcalase and trypsin was performed by employing the central composite design (CCD) of response surface methodology (RSM). The independent variables were solid-to-liquid ratio (S/L), enzyme-to-substrate ratio (E/S), pH, and reaction temperature, while the response variables were degree of hydrolysate (DH), α-amylase, and α-glucosidase inhibitory activity. The highest DH (22.84% and 14.63%), α-amylase inhibition (56.78% and 40.80%), and α-glucosidase inhibition (86.37% and 86.51%) were obtained under optimal conditions, which were S/L of 1:26.22 and 1:30 w/v, E/S of 6% and 5.67%, pH of 8.41 and 8.56, and temperature of 56.18 °C and 58.75 °C at 3 h using alcalase (AH) and trypsin (TH), respectively. Molecular weight distributions of peanut protein hydrolysates were characterized by SDS-PAGE, which were mostly ˂10 kDa for both hydrolysates. Lyophilized AH and TH had IC₅₀ values of 6.77 and 5.86 mg/mL for α-amylase inhibitory activity, and 6.28 and 5.64 mg/mL for α-glucosidase inhibitory activity. The IC₅₀ of AH and TH against DPPH radical was achieved at 4.10 and 3.20 mg/mL and against ABTS radical at 2.71 and 2.32 mg/mL, respectively. The obtained hydrolysates with antidiabetic activity could be utilized as natural alternatives to synthetic antidiabetics, particularly in food and pharmaceutical products.

Investigating the cellular antioxidant and anti-inflammatory effects of the novel peptides in lingzhi mushrooms

The lingzhi mushroom (Ganoderma lucidum) is well known for its medicinal properties and has long played a role in traditional oriental medicine due to its health-giving benefits and potential to extend life expectancy. The mushroom contains a number of highly bioactive compounds and can also act as an excellent source of protein. This research investigated the peptides obtained from the protein hydrolysates of lingzhi mushrooms to assess their free radical scavenging abilities. These peptides were acquired via different proteases (Alcalase, Neutrase, papain, and pepsin-pancreatin) and were tested at a range of different concentrations (1.0%, 2.5%, and 5.0% w/v). The highest levels of 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) radical scavenging activities were presented by lingzhi mushroom hydrolysate using 2.5% (w/v) pepsin-pancreatin after 6 h of digestion. The hydrolysate was then fractionated using 10, 5, 3, and 0.65 kDa molecular weight cut-off membranes. The results showed that the MW 0.65 kDa fraction had the highest level of free radical scavenging activity. Further analysis of this MW 0.65 kDa fraction began with another RP-HPLC fractionation technique to obtain three further sub-fractions. De novo peptide sequencing using electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF-MS/MS) was chosen as the optimum method for studying the F₃ sub-fraction. DRVSIYGWG and ALLSISSF were discovered as new peptides with different antioxidant properties. Adenocarcinoma colon (Caco-2) cells showed the antioxidant action of these synthesized peptides. This activity was linked to peptide concentration. The peptides and their pure synthetic counterparts were found to reduce NO generation by RAW 264.7 macrophages without causing cytotoxicity. The results of gene expression reveal that the DRVSIYGWG and ALLSISSF peptides were able to cut the expression of the proinflammatory cytokine genes iNOS, IL-6, TNF-α, and COX-2 in the context of RAW 264.7 macrophages.

Functional dairy products as a source of bioactive peptides and probiotics: current trends and future prospectives

Milk is an incredibly healthy food world-wide. However, the 'lactase deficient' individuals cannot digest milk's carbohydrate lactose. A large part of the world population is depriving of highly beneficial milk proteins like casein, lactoalbumin, lactoglobulin, etc. due to lactose intolerance. Production of functional foods and bioactive peptides from milk with natural antioxidants and the addition of probiotics could be the best alternative to extend the use of milk functionalities. Among different probiotics, the lactic acid bacteria (LAB) like Lactobacillus delbrueckii sub sp. bulgaricus, Streptococcus thermophilus and some species of Bifidobacteria and their metabolites (paraprobiotics and postbiotics) have been given more preference to add in milk-derived functional foods. These species are generally considered as heat-tolerant, highly proteolytic, and peptidolytic towards milk proteins and they liberate smaller molecules of bioactive peptides during fermentation and other processes that stimulate the enzyme lactase to help people in digestion of milk carbohydrate lactose. Moreover, the incorporation of natural antioxidants in yoghurt and other dairy products prevents the rancidity of milk fat. The level of bioactive peptides produced in milk-derived functional foods can be determined by capillary zone electrophoresis, mass spectrometry, fractionation, and other modern assessment techniques. Commercial production of functional probiotic products with bioactive peptides could significantly contribute to reduce milk spoilage, enhance health benefits as well as the growth of the agro-processing industry.

Antioxidant and Antimicrobial Peptides Derived from Food Proteins

Recently, the demand for food proteins in the market has increased due to a rise in degenerative illnesses that are associated with the excessive production of free radicals and the unwanted side effects of various drugs, for which researchers have suggested diets rich in bioactive compounds. Some of the functional compounds present in foods are antioxidant and antimicrobial peptides, which are used to produce foods that promote health and to reduce the consumption of antibiotics. These peptides have been obtained from various sources of proteins, such as foods and agri-food by-products, via enzymatic hydrolysis and microbial fermentation. Peptides with antioxidant properties exert effective metal ion (Fe2+/Cu2+) chelating activity and lipid peroxidation inhibition, which may lead to notably beneficial effects in promoting human health and food processing. Antimicrobial peptides are small oligo-peptides generally containing from 10 to 100 amino acids, with a net positive charge and an amphipathic structure; they are the most important components of the antibacterial defense of organisms at almost all levels of life-bacteria, fungi, plants, amphibians, insects, birds and mammals-and have been suggested as natural compounds that neutralize the toxicity of reactive oxygen species generated by antibiotics and the stress generated by various exogenous sources. This review discusses what antioxidant and antimicrobial peptides are, their source, production, some bioinformatics tools used for their obtainment, emerging technologies, and health benefits.

Use of Alcalase in the production of bioactive peptides: A review

This review aims to cover the uses of the commercially available protease Alcalase in the production of biologically active peptides since 2010. Immobilization of Alcalase has also been reviewed, as immobilization of the enzyme may improve the final reaction design enabling the use of more drastic conditions and the reuse of the biocatalyst. That way, this review presents the production, via Alcalase hydrolysis of different proteins, of peptides with antioxidant, angiotensin I-converting enzyme inhibitory, metal binding, antidiabetic, anti-inflammatory and antimicrobial activities (among other bioactivities) and peptides that improve the functional, sensory and nutritional properties of foods. Alcalase has proved to be among the most efficient proteases for this goal, using different protein sources, being especially interesting the use of the protein residues from food industry as feedstock, as this also solves nature pollution problems. Very interestingly, the bioactivities of the protein hydrolysates further improved when Alcalase is used in a combined way with other proteases both in a sequential way or in a simultaneous hydrolysis (something that could be related to the concept of combi-enzymes), as the combination of proteases with different selectivities and specificities enable the production of a larger amount of peptides and of a smaller size.

Production and processing of antioxidant bioactive peptides: A driving force for the functional food market

Recently, the demand for functional foods in the global market has increased rapidly due to the increasing occurrences of non-communicable diseases and technological advancement. Antioxidant peptides have been suggested as ingredients used to produce health-promoting foods. These peptides are encrypted from various food derived protein sources by chemical and enzymatic hydrolysis, and microbial fermentation. However, the industrial-scale production of antioxidant peptides is hampered by different problems such as high production cost, and low yield and bioactivity. Accordingly, novel processing technologies, such as high pressure, microwave and pulsed electric field, have been recently emerged to overcome the problems associated with the conventional hydrolysis methods. This particular review, therefore, discussed the current processing technologies used to produce antioxidant peptides. The review also suggested further perspectives that should be addressed in the future.

Advances on Food-Derived Peptidic Antioxidants-A Review

The oxidation process is considered to be the main reason behind human aging, human degenerative diseases and food quality degradation. Food-derived peptidic antioxidants (PAs) have wide sources and great activity, and have broad application prospects in removing excess reactive oxygen species in the body, anti-aging and preventing and treating diseases related to oxidative stress. On the other hand, PAs are expected to inhibit the lipid peroxidation of foods and increase the stability of the food system in the food industry. However, the production pathways and action mechanism of food-derived PAs are diverse, which makes it is difficult to evaluate the performance of PAs which is why the commercial application of PAs is still in its infancy. This article focuses on reviewing the preparation, purification, and characterization methods of food-derived PAs, and expounds the latest progress in performance evaluation and potential applications, in order to provide an effective reference for subsequent related research of PAs.