Improving Health-Promoting Effects of Food-Derived Bioactive Peptides through Rational Design and Oral Delivery Strategies

Loading bioactive peptides within different nanocarriers to enhance their functionality and bioavailability; in vitro and in vivo studies

A hydrolyzed protein is a blend of peptides and amino acids which is the result of hydrolysis by enzymes, acids or alkalis. The Bioactive Peptides (BPs) show important biological roles including antioxidant, antimicrobial, anti-diabetic, anti-cancer, and anti-hypertensive effects, as well as positive effects on the immune, nervous, and digestive systems. Despite the benefits of BPs, challenges such as undesired organoleptic properties, solubility profile, chemical instability, and low bioavailability limit their use in functional food formulations and dietary supplements. Nanocarriers have emerged as a promising solution for overcoming these challenges by improving the stability, solubility, resistance to gastric digestion, and bioavailability, allowing for the targeted and controlled delivery, and reduction or masking of the undesirable flavor of BPs. This study reviews the recent scientific accomplishments concerning the loading of BPs into various nanocarriers including lipid, carbohydrate and protein based-nanocarriers. A special emphasis is given to their application in food formulations in accordance to the challenges associated with their use.

Special Issue: "Rational Design and Synthesis of Bioactive Molecules"

The rational design of novel bioactive molecules is a critical but challenging task in drug discovery [...].

Exploring the impact of encapsulation on the stability and bioactivity of peptides extracted from botanical sources: trends and opportunities

Bioactive peptides derived from plant sources have gained significant attention for their potential use in preventing and treating chronic degenerative diseases. However, the efficacy of these peptides depends on their bioaccessibility, bioavailability, and stability. Encapsulation is a promising strategy for improving the therapeutic use of these compounds. It enhances their stability, prolongs their shelf life, protects them from degradation during digestion, and enables better release control by improving their bioaccessibility and bioavailability. This review aims to analyze the impact of various factors related to peptide encapsulation on their stability and release to enhance their biological activity. To achieve this, it is necessary to determine the composition and physicochemical properties of the capsule, which are influenced by the wall materials, encapsulation technique, and operating conditions. Furthermore, for peptide encapsulation, their charge, size, and hydrophobicity must be considered. Recent research has focused on the advancement of novel encapsulation methodologies that permit the formation of uniform capsules in terms of size and shape. In addition, it explores novel wall materials, including polysaccharides derived from unconventional sources, that allow the precise regulation of the rate at which peptides are released into the intestine.

Angiotensin-Converting Enzyme and Renin-Inhibitory Activities of Protein Hydrolysates Produced by Alcalase Hydrolysis of Peanut Protein

Hypertension is a major controllable risk factor associated with cardiovascular disease (CVD) and overall mortality worldwide. Most people with hypertension must take medications that are effective in blood pressure management but cause many side effects. Thus, it is important to explore safer antihypertensive alternatives to regulate blood pressure. In this study, peanut protein concentrate (PPC) was hydrolyzed with 3-5% Alcalase for 3-10 h. The in vitro angiotensin-converting enzyme (ACE) and renin-inhibitory activities of the resulting peanut protein hydrolysate (PPH) samples and their fractions of different molecular weight ranges were determined as two measures of their antihypertensive potentials. The results show that the crude PPH produced at 4% Alcalase for 6 h of hydrolysis had the highest ACE-inhibitory activity with IC50 being 5.45 mg/mL. The PPH samples produced with 3-5% Alcalase hydrolysis for 6-8 h also displayed substantial renin-inhibitory activities, which is a great advantage over the animal protein-derived bioactive peptides or hydrolysate. Remarkably higher ACE- and renin-inhibitory activities were observed in fractions smaller than 5 kDa with IC50 being 0.85 and 1.78 mg/mL. Hence, the PPH and its small molecular fraction produced under proper Alcalase hydrolysis conditions have great potential to serve as a cost-effective anti-hypertensive ingredient for blood pressure management.

Potential Impact of Bioactive Peptides from Foods in the Treatment of Hypertension

SCOPE

High blood pressure (BP) is the main preventable risk factor for cardiovascular diseases (CVDs). Much research is aimed at finding natural alternatives to control or prevent hypertension (HT), since some hypertensive patients do not respond to current pharmacological treatments or show undesirable side effects.

METHODS AND RESULTS

Forty relevant articles have been selected from various scientific literature databases. The results reveal that angiotensin-converting enzyme (ACE) inhibition is the most reported mechanism of action of antihypertensive peptides. The active peptides have a great variety of origins. Biopeptides with a molecular weight of <3 kDa, short chain <20 amino acids, and a hydrophobic amino acid sequence at the C- and N-terminus exhibit higher antihypertensive activity. They also show good stability to enzymatic hydrolysis and gastrointestinal digestion, and no toxicity. To determine antihypertensive effectiveness, in vitro and in vivo animal studies are the most frequent developed, with few in silico studies and only one human clinical trial.

CONCLUSION

There is interesting potential for antihypertensive peptides as promising natural candidates for the development of functional foods, nutraceuticals and drugs for preventive or therapeutic treatment of hypertension. The aim of this review is to study the role of food-derived bioactive peptides in HT.

Production, characterization, and potential applications of lipopeptides in food systems: A comprehensive review

Lipopeptides are a class of lipid-peptide-conjugated compounds with differing structural features. This structural diversity is responsible for their diverse range of biological properties, including antimicrobial, antioxidant, and anti-inflammatory activities. Lipopeptides have been attracting the attention of food scientists due to their potential as food additives and preservatives. This review provides a comprehensive overview of lipopeptides, their production, structural characteristics, and functional properties. First, the classes, chemical features, structure-activity relationships, and sources of lipopeptides are summarized. Then, the gene expression and biosynthesis of lipopeptides in microbial cell factories and strategies to optimize lipopeptide production are discussed. In addition, the main methods of purification and characterization of lipopeptides have been described. Finally, some biological activities of the lipopeptides, especially those relevant to food systems along with their mechanism of action, are critically examined.

Antioxidant peptides generated from chicken feet protein hydrolysates

BACKGROUND

As major industrial poultry by-products, chicken feet are considered as notable sources of several bioactive molecules. The current work covers the processing of chicken feet proteins as substrates to be hydrolysed by combinations of three commercial enzymes (Alcalase®, Flavourzyme® and Protana® Prime) during different hydrolysis periods and the evaluation of the identified peptides having antioxidant activity after simulated gastrointestinal digestion.

RESULTS

Enzymatic hydrolysis with Alcalase® and Protana® Prime combination for 4 h resulted in the highest activities. Reversed-phase high-performance liquid chromatographic separation of the purified hydrolysate yielded three active fractions that were further identified by nano-liquid chromatography-tandem mass spectrometry. The bioactivities of over 230 identified peptide sequences were estimated after simulated gastrointestinal digestion, and those peptides with the highest chance of exerting antioxidant activity were selected to be further synthesised and tested. In this sense, the synthesised dipeptides CF and GY showed the highest antioxidant capacity. CF presented IC50 values of 69.63 and 145.41 μmol L-1 in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC) assays, respectively. In contrast, GY IC50 values were 15.27 and 10.06 μmol L-1 in ABTS and ORAC assays, respectively. Significant differences (P < 0.05) were registered between peptides in the same antioxidant assays.

CONCLUSION

Overall, the findings emphasised the favourable impact of enzymatic hydrolysis with the obtaining of antioxidant peptides from poultry by-products that could be evaluated as a safe and economical source to retard oxidation in food systems. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Recent advances in the development of therapeutic peptides

Peptides have unique characteristics that make them highly desirable as therapeutic agents. The physicochemical and proteolytic stability profiles determine the therapeutic potential of peptides. Multiple strategies to enhance the therapeutic profile of peptides have emerged. They include chemical modifications, such as cyclization, substitution with d-amino acids, peptoid formation, N-methylation, and side-chain halogenation, and incorporation in delivery systems. There have been recent advances in approaches to discover peptides having these modifications to attain desirable therapeutic properties. We critically review these recent advancements in therapeutic peptide development.

Food Peptides for the Nutricosmetic Industry

In recent years, numerous reports have described bioactive peptides (biopeptides)/hydrolysates produced from various food sources. Biopeptides are considered interesting for industrial application since they show numerous functional properties (e.g., anti-aging, antioxidant, anti-inflammatory, and antimicrobial properties) and technological properties (e.g., solubility, emulsifying, and foaming). Moreover, they have fewer side effects than synthetic drugs. Nevertheless, some challenges must be overcome before their administration via the oral route. The gastric, pancreatic, and small intestinal enzymes and acidic stomach conditions can affect their bioavailability and the levels that can reach the site of action. Some delivery systems have been studied to avoid these problems (e.g., microemulsions, liposomes, solid lipid particles). This paper summarizes the results of studies conducted on biopeptides isolated from plants, marine organisms, animals, and biowaste by-products, discusses their potential application in the nutricosmetic industry, and considers potential delivery systems that could maintain their bioactivity. Our results show that food peptides are environmentally sustainable products that can be used as antioxidant, antimicrobial, anti-aging, and anti-inflammatory agents in nutricosmetic formulations. Biopeptide production from biowaste requires expertise in analytical procedures and good manufacturing practice. It is hoped that new analytical procedures can be developed to simplify large-scale production and that the authorities adopt and regulate use of appropriate testing standards to guarantee the population's safety.

Peanut Allergenicity: An Insight into Its Mitigation Using Thermomechanical Processing

Peanuts are the seeds of a legume crop grown for nuts and oil production. Peanut allergy has gained significant attention as a public health issue due to its increasing prevalence, high rate of sensitization, severity of the corresponding allergic symptoms, cross-reactivity with other food allergens, and lifelong persistence. Given the importance of peanuts in several sectors, and taking into consideration the criticality of their high allergic potential, strategies aiming at mitigating their allergenicity are urgently needed. In this regard, most of the processing methods used to treat peanuts are categorized as either thermal or thermomechanical techniques. The purpose of this review is to provide the reader with an updated outlook of the peanut’s allergens, their mechanisms of action, the processing methods as applied to whole peanuts, as well as a critical insight on their impact on the allergenicity. The methods discussed include boiling, roasting/baking, microwaving, ultrasonication, frying, and high-pressure steaming/autoclaving. Their effectiveness in alleviating the allergenicity, and their capacity in preserving the structural integrity of the treated peanuts, were thoroughly explored. Research data on this matter may open further perspectives for future relevant investigation ultimately aiming at producing hypoallergenic peanuts.

From In Silico to a Cellular Model: Molecular Docking Approach to Evaluate Antioxidant Bioactive Peptides

The increasing need to counteract the redox imbalance in chronic diseases leads to focusing research on compounds with antioxidant activity. Among natural molecules with health-promoting effects on many body functions, bioactive peptides are gaining interest. They are protein fragments of 2–20 amino acids that can be released by various mechanisms, such as gastrointestinal digestion, food processing and microbial fermentation. Recent studies report the effects of bioactive peptides in the cellular environment, and there is evidence that these compounds can exert their action by modulating specific pathways. This review focuses on the newest approaches to the structure–function correlation of the antioxidant bioactive peptides, considering their molecular mechanism, by evaluating the activation of specific signaling pathways that are linked to antioxidant systems. The correlation between the results of in silico molecular docking analysis and the effects in a cellular model was highlighted. This knowledge is fundamental in order to propose the use of bioactive peptides as ingredients in functional foods or nutraceuticals.

Bioactive protein hydrolysates obtained from amaranth by fermentation with lactic acid bacteria and Bacillus species

Protein hydrolysates are a promising source of bioactive peptides. One strategy by which they can be obtained is fermentation. This method uses the proteolytic system of microorganisms to hydrolyze the parental protein. Fermentation is a little-explored method for obtaining protein hydrolysates from amaranth. Different strains of lactic acid bacteria (LAB) and Bacillus species isolated from goat milk, broccoli, aguamiel, and amaranth flour were used in this work. First, the total protein degradation (%TPD) of amaranth demonstrated by the strains was determined. The results ranged from 0 to 95.95%, the strains that produced a higher %TPD were selected. These strains were identified by molecular biology and were found to correspond to the genera Enterococcus, Lactobacillus, Bacillus, and Leuconostoc. Fermentation was carried out with amaranth flour and the selected strains. After this process, water/salt extracts (WSE) containing the released protein hydrolysates were obtained from amaranth doughs. The peptide concentration was measured by the OPA method. The antioxidant, antihypertensive and antimicrobial activity of the WSE was evaluated. In the FRAP test, the best WSE was LR9 with a concentration of 1.99 μMTE/L ± 0.07. In ABTS, 18C6 obtained the highest concentration with 19.18 μMTE/L ± 0.96. In the DPPH test, there was no significant difference. In terms of antihypertensive activity, inhibition percentages ranging from 0 to 80.65% were obtained. Some WSE were found to have antimicrobial properties against Salmonella enterica and Listeria monocytogenes. Fermentation of amaranth with LAB and Bacillus spp. allowed the release of protein hydrolysates with antioxidant, antihypertensive, and antimicrobial activity.

Bioactive and Sensory Di- and Tripeptides Generated during Dry-Curing of Pork Meat

Dry-cured pork products, such as dry-cured ham, undergo an extensive proteolysis during manufacturing process which determines the organoleptic properties of the final product. As a result of endogenous pork muscle endo- and exopeptidases, many medium- and short-chain peptides are released from muscle proteins. Many of them have been isolated, identified, and characterized, and some peptides have been reported to exert relevant bioactivity with potential benefit for human health. However, little attention has been given to di- and tripeptides, which are far less known, although they have received increasing attention in recent years due to their high potential relevance in terms of bioactivity and role in taste development. This review gathers the current knowledge about di- and tripeptides, regarding their bioactivity and sensory properties and focusing on their generation during long-term processing such as dry-cured pork meats.

Nanomedicine based potentially transformative strategies for colon targeting of peptides: State-of-the-art

Recently, peptides have attracted tremendous attention among researchers attributed to their high target specificity and efficacy compared to conventional therapeutics. The ease of self-administration and non-invasiveness confers oral as the most desirable route. However, numerous challenges associated with peptide delivery through the oral route like harsh gastrointestinal environment, enzymatic degradation, and absorption barriers hinder its clinical translation. Protease activity is more pronounced in the proximal segments of the gastrointestinal tract (GIT). Distal segments like the colon possess lower proteolytic activity, enhanced retention time, etc. which could facilitate easy absorption. However, traversing of the upper segments to reach the colon requires the circumvention of the pitfalls of the GIT. The advent of nanomedicine strategies could help in overcoming the said challenges associated with oral delivery, colon-specific targeting, and improving stability and bioavailability at the active site. Furthermore, the classification of peptides and various nanomedicine strategies for oral delivery of peptides to the colon has been conveyed. Regulatory hurdles and ways to accomplish clinical translation have been addressed.

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.

The current research status and strategies employed to modify food-derived bioactive peptides

The ability of bioactive peptides to exert biological functions has mainly contributed to their exploitation. The exploitation and utilization of these peptides have grown tremendously over the past two decades. Food-derived peptides from sources such as plant, animal, and marine proteins and their byproducts constitute a more significant portion of the naturally-occurring peptides that have been documented. Due to their high specificity and biocompatibility, these peptides serve as a suitable alternative to pharmacological drugs for treating non-communicable diseases (such as cardiovascular diseases, obesity, and cancer). They are helpful as food preservatives, ingredients in functional foods, and dietary supplements in the food sector. Despite their unique features, the application of these peptides in the clinical and food sector is to some extent hindered by their inherent drawbacks such as toxicity, bitterness, instability, and susceptibility to enzymatic degradation in the gastrointestinal tract. Several strategies have been employed to eliminate or reduce the disadvantages of peptides, thus enhancing the peptide bioactivity and broadening the opportunities for their applications. This review article focuses on the current research status of various bioactive peptides and the strategies that have been implemented to overcome their disadvantages. It will also highlight future perspectives regarding the possible improvements to be made for the development of bioactive peptides with practical uses and their commercialization.

Health Beneficial Bioactivities of Faba Bean Gastrointestinal (In Vitro) Digestate in Comparison to Soybean and Pea

Faba beans are a promising emerging plant-based protein source to be used as a quality alternative to peas and soy. In this study, the potential health beneficial activities of three Canadian faba bean varieties (Fabelle, Malik and Snowbird) were investigated after in vitro gastrointestinal digestion and compared to two commonly used legumes (peas and soy). The results revealed that the faba beans had a higher antioxidant activity than peas when assessed with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays, except for the Fabelle variety. In the oxygen radical absorbance capacity (ORAC) and the iron chelating assays, the faba beans had a lower antioxidant activity than soy. Interestingly, Fabelle and Snowbird showed a higher antioxidant effect than the peas and soy at the cellular level. The antihypertensive properties of Fabelle and Malik varieties were significantly higher than peas but lower than soy. The in vitro antidiabetic activity was higher for soy, but no differences were found at the cellular level. The faba bean peptides were further fractionated and sequenced by mass spectrometry. Eleven peptides with in silico predicted bioactivities were successfully identified in the faba bean digestate and support validating the health-promoting properties of peptides. The results demonstrate the bioactive potential of faba beans as a health-promoting food ingredient against non-communicable diseases.

Quantitative In Silico Evaluation of Allergenic Proteins from Anacardium occidentale, Carya illinoinensis, Juglans regia and Pistacia vera and Their Epitopes as Precursors of Bioactive Peptides

The aim of the study presented here was to determine if there is a correlation between the presence of specific protein domains within tree nut allergens or tree nut allergen epitopes and the frequency of bioactive fragments and the predicted susceptibility to enzymatic digestion in allergenic proteins from tree nuts of cashew (Anacardium occidentale), pecan (Carya illinoinensis), English walnut (Juglans regia) and pistachio (Pistacia vera) plants. These bioactive peptides are distributed along the length of the protein and are not enriched in IgE epitope sequences. Classification of proteins as bioactive peptide precursors based on the presence of specific protein domains may be a promising approach. Proteins possessing a vicilin, N-terminal family domain, or napin domain contain a relatively low occurrence of bioactive fragments. In contrast, proteins possessing the cupin 1 domain without the vicilin N-terminal family domain contain a relatively high total frequency of bioactive fragments and predicted release of bioactive fragments by the joint action of pepsin, trypsin, and chymotrypsin. This approach could be utilized in food science to simplify the selection of protein domains enriched for bioactive peptides.

Plant-derived proteins as a sustainable source of bioactive peptides: recent research updates on emerging production methods, bioactivities, and potential application

The development of novel protein sources to compensate for the expected future shortage of traditional animal proteins due to their high carbon footprint is a major contemporary challenge in the agri-food industry currently. Therefore, both industry and consumers are placing a greater emphasis on plant proteins as a sustainable source of protein to meet the growing nutritional demand of ever increasing population. In addition to being key alternatives, many plant-based foods have biological properties that make them potentially functional or health-promoting foods, particularly physiologically active peptides and proteins accounting for most of these properties. This review discusses the importance of plant-based protein as a viable and sustainable alternative to animal proteins. The current advances in plant protein isolation and production and characterization of bioactive hydrolysates and peptides from plant proteins are described comprehensively. Furthermore, the recent research on bioactivities and bioavailability of plant protein-derived bioactive peptides is reviewed briefly. The limitations of using bioactive peptides, regulatory criteria, and the possible future applications of plant protein-derived bioactive peptides are highlighted. This review may help understand plant proteins and their bioactive peptides and provide valuable suggestions for future research and applications in the food industry.

Nrf2-Activating Bioactive Peptides Exert Anti-Inflammatory Activity through Inhibition of the NF-κB Pathway

Redox status and inflammation are related to the pathogenesis of the majority of diseases. Therefore, understanding the role of specific food-derived molecules in the regulation of their specific pathways is a relevant issue. Our previous studies indicated that K-8-K and S-10-S, milk and soy-derived bioactive peptides, respectively, exert antioxidant effects through activation of the Keap1/Nrf2 pathway. A crosstalk between Nrf2 and NF-κB, mediated by the action of heme oxygenase (HO-1), is well known. On this basis, we studied if these peptides, in addition to their antioxidant activity, could exert anti-inflammatory effects in human cells. First, we observed an increase of HO-1 expression in Caco-2 cells treated with K-8-K and S-10-S, following the activation of the Keap1/Nrf2 pathway. Moreover, when cells are treated with the two peptides and stimulated by TNF-α, the levels of NF-κB in the nucleus decreased in comparison with TNF-α alone. In the same conditions, we observed the downregulation of the gene expression of proinflammatory cytokines (IL1B, IL6, and TNF), while the anti-inflammatory cytokine gene, IL1RN, was upregulated in Caco-2 cells processed as reported above. Then, when the cells were pretreated with the two peptides and stimulated with LPS, a different proinflammatory factor, (TNF-α) was estimated to have a lower secretion in the supernatant of cells. In conclusion, these observations confirmed that Nrf2-activating bioactive peptides, K-8-K and S-10-S, exerted anti-inflammatory effects by inhibiting the NF-κB pathway.

Faba Bean: An Untapped Source of Quality Plant Proteins and Bioactives

Faba beans are emerging as sustainable quality plant protein sources, with the potential to help meet the growing global demand for more nutritious and healthy foods. The faba bean, in addition to its high protein content and well-balanced amino acid profile, contains bioactive constituents with health-enhancing properties, including bioactive peptides, phenolic compounds, GABA, and L-DOPA. Faba bean peptides released after gastrointestinal digestion have shown antioxidant, antidiabetic, antihypertensive, cholesterol-lowering, and anti-inflammatory effects, indicating a strong potential for this legume crop to be used as a functional food to help face the increasing incidences of non-communicable diseases. This paper provides a comprehensive review of the current body of knowledge on the nutritional and biofunctional qualities of faba beans, with a particular focus on protein-derived bioactive peptides and how they are affected by food processing. It further covers the adverse health effects of faba beans associated with the presence of anti-nutrients and potential allergens, and it outlines research gaps and needs.

Effect of oral and intraperitoneal administration of walnut-derived pentapeptide PW5 on cognitive impairments in APPSWE/PS1ΔE9 mice

Food-derived bioactive peptides, encrypted in native protein sequence, have attracted enormous research attention due to its potential in the prevention and/or treatment of a broad range of diseases. However, administration route poses a great challenge to their development and commercial applications. Patient-friendly delivery of bioactive peptides which also enhances its efficacy urgently remain to be addressed. Here we compared the effects of oral administration (PO) to intraperitoneal injection (IP) of a walnut-derived bioactive pentapeptide PW5 (Pro-Pro-Lys-Asn-Trp) in cognitive improvement capacity in APP_SWE/PS1_ΔE9 transgenic mice. Strikingly, we found that only PO administration of PW5 could effectively ameliorate cognitive impairments and reduce the β-amyloid deposits in the brain compared to the IP administration. This may be attributable to alterations in the gut microbiota communities, including alterations in microbial α- and β-diversities after PO treatment, leading to the reversal of the relative abundances of ten differential genera (e.g. Acinetobacter, Lactobacillus, Akkermansia, Allobaculum, Adlercreutzia, Coriobacteriaceae, unclassified_p_ Firmicutes, Desulfovibrionaceae, Oscillospira and Anaeroplasma) which are highly correlated with disease progression. Thus, this study has leveraged on PW5 to proof the superior efficacy of oral delivery to injection delivery in improving cognitive impairments in vivo, suggesting that oral delivery might be highly recommended as a prioritized delivery route in the development of food-derived peptides.

Macroalgal Proteins: A Review

Population growth is the driving change in the search for new, alternative sources of protein. Macroalgae (otherwise known as seaweeds) do not compete with other food sources for space and resources as they can be sustainably cultivated without the need for arable land. Macroalgae are significantly rich in protein and amino acid content compared to other plant-derived proteins. Herein, physical and chemical protein extraction methods as well as novel techniques including enzyme hydrolysis, microwave-assisted extraction and ultrasound sonication are discussed as strategies for protein extraction with this resource. The generation of high-value, economically important ingredients such as bioactive peptides is explored as well as the application of macroalgal proteins in human foods and animal feed. These bioactive peptides that have been shown to inhibit enzymes such as renin, angiotensin-I-converting enzyme (ACE-1), cyclooxygenases (COX), α-amylase and α-glucosidase associated with hypertensive, diabetic, and inflammation-related activities are explored. This paper discusses the significant uses of seaweeds, which range from utilising their anthelmintic and anti-methane properties in feed additives, to food techno-functional ingredients in the formulation of human foods such as ice creams, to utilising their health beneficial ingredients to reduce high blood pressure and prevent inflammation. This information was collated following a review of 206 publications on the use of seaweeds as foods and feeds and processing methods to extract seaweed proteins.

Insight of nanotechnological processing for nano-fortified functional foods and nutraceutical-opportunities, challenges, and future scope in food for better health

In the twenty-first century food sector, nanotechnological processing is a new frontier that has vibrant impact on enhancing the food quality, nutritional value, food safety, and nano-fortified functional foods aspects. In addition, the added-value of various robust nano-scale materials facilitates the targeted delivery of nutraceutical ingredients and treatment of obesity and comorbidities. The recent advancement in nanomaterial-assisted palatability enhancement of healthy foods opened up a whole new area of research and development in food nanoscience. However, there is no comprehensive review available on promises of nanotechnology in the food industry in the existing literature. Thus, herein, an effort has been made to cover this leftover literature gap by spotlighting the new nanotechnological frontier and their future scope in food engineering for better health. Following a brief introduction, promises of nanotechnology have revolutionized the twenty-first century food sector of the modern world. Next, recent and relevant examples discuss the exploitation and deployment of nanomaterials in food to attain certain health benefits. A detailed insight is also given by discussing the role of nano-processing in nutraceutical delivery to treat obesity and comorbidities. The latter half of the work focuses on improving healthy foods' palatability and food safety aspects to meet the growing consumer demands. Furthermore, marketed products and public acceptance of nanotechnologically designed food items as well as future prospects are also covered herein.

Lupin-Derived Bioactive Peptides: Intestinal Transport, Bioavailability and Health Benefits

There is a renewed interest on the reliance of food-based bioactive compounds as sources of nutritive factors and health-beneficial chemical compounds. Among these food components, several proteins from foods have been shown to promote health and wellness as seen in proteins such as α/γ-conglutins from the seeds of Lupinus species (Lupin), a genus of leguminous plant that are widely used in traditional medicine for treating chronic diseases. Lupin-derived peptides (LDPs) are increasingly being explored and they have been shown to possess multifunctional health improving properties. This paper discusses the intestinal transport, bioavailability and biological activities of LDPs, focusing on molecular mechanisms of action as reported in in vitro, cell culture, animal and human studies. The potentials of several LDPs to demonstrate multitarget mechanism of regulation of glucose and lipid metabolism, chemo- and osteoprotective properties, and antioxidant and anti-inflammatory activities position LDPs as good candidates for nutraceutical development for the prevention and management of medical conditions whose etiology are multifactorial.

Bioactive Peptides as Potential Nutraceuticals for Diabetes Therapy: A Comprehensive Review

Diabetes mellitus is a major public health concern associated with high mortality and reduced life expectancy. The alarming rise in the prevalence of diabetes is linked to several factors including sedentary lifestyle and unhealthy diet. Nutritional intervention and increased physical activity could significantly contribute to bringing this under control. Food-derived bioactive peptides and protein hydrolysates have been associated with a number health benefits. Several peptides with antidiabetic potential have been identified that could decrease blood glucose level, improve insulin uptake and inhibit key enzymes involved in the development and progression of diabetes. Dietary proteins, from a wide range of food, are rich sources of antidiabetic peptides. Thus, there are a number of benefits in studying peptides obtained from food sources to develop nutraceuticals. A deeper understanding of the underlying molecular mechanisms of these peptides will assist in the development of new peptide-based therapeutics. Despite this, a comprehensive analysis of the antidiabetic properties of bioactive peptides derived from various food sources is still lacking. Here, we review the recent literature on food-derived bioactive peptides possessing antidiabetic activity. The focus is on the effectiveness of these peptides as evidenced by in vitro and in vivo studies. Finally, we discuss future prospects of peptide-based drugs for the treatment of diabetes.

Bioactive peptide release and the absorption tracking of casein in the gastrointestinal digestion of rats

Bovine casein is considered as an important source of many bioactive peptides (BAPs), which can also be produced via in vitro simulated gastrointestinal hydrolysis. To perform their physiological functions, some active peptides need to pass through the intestinal epithelial barrier and keep their structural integrity after oral administration. Owing to the complexity of in vivo digestion and absorption, there have been few studies in this area. In this study, casein was labeled with FITC to trace its digestion and absorption in Sprague Dawley (SD) rats. Gastric juice, intestinal fluid, blood, and intestinal tissue samples were collected at different time-points for preservation and analysis after intragastric administration. The results showed that CN-FITC exhibited good labeling stability in the gastrointestinal digestive juice both in vivo and in vitro, suggesting its potential to be used for the detection and tracking of casein hydrolysate. After the intra-gastric administration of FITC, the diffusion rates of fluorescent substances in serum were much higher than in the CN-FITC group. The maximum peptide content in the CN-FITC group during intestinal digestion was achieved 2 h after administration, and electrophoretic analysis of the hydrolysate composition suggested that the molecular weights of the peptides were mainly concentrated in the range of 3.4-10 kDa. The hydrolyzed peptides from CN-FITC could be absorbed into the blood just 1 h after administration. Frozen sections of rat duodenal tissue were observed under a confocal laser scanning microscope, and they showed that the CN-FITC digested products were absorbed from villi to mucosa in the rat intestines, and the casein-hydrolyzed polypeptides were accumulated significantly in tissue samples 2 h after administration. The peptides were mainly absorbed in the duodenum on the basis of absorption experiments using an everted gut sac. After intestinal digestion for 2 h, peptides with weights less than 5 kDa were enriched and identified using LC-MS-MS, and they were found to be mainly derived from β-casein, containing potential angiotensin-I-converting enzyme inhibitory, antioxidant, dipeptidyl peptidase IV inhibitory, and morphine-like peptides. The peptides from casein hydrolysate were tracked entering the blood through the intestinal epithelial barrier in the form of complete fragments, and they might exert potential physiological activity in vivo.

Assessment of the biological activity of fish muscle protein hydrolysates using in vitro model systems

The generation of biologically active fish protein hydrolysates (FPH) is a useful technique to produce value-added products with potential application in the functional food and nutraceutical industries. Fish muscle is an attractive substrate for the production of protein hydrolysates due to its rich protein content, containing 15-25% of total fish protein. This paper reviews the production of protein hydrolysates from fish muscle, most commonly via enzymatic hydrolysis, and their subsequent bioactivities including anti-obesity, immunomodulatory, antioxidant, angiotensin I-converting enzyme (ACE)-inhibitory, anti-microbial, and anti-cancer activities as measured by in vitro testing methods. Disease prevention with FPH potentially offers a safe and natural alternative to synthetic drugs. Small molecular weight (MW) FPHs generally exhibit favourable bioactivity than large MW fractions via enhanced absorption through the gastrointestinal tract. This review also discusses the relationship between amino acid (AA) composition and AA sequence of FPH and peptides and their exhibited in vitro bioactivity.

Novel ACE Inhibitory Peptides Derived from Yeast Hydrolysates: Screening, Inhibition Mechanisms and Effects on HUVECs

The antihypertensive activity of yeast hydrolysate (YH) was confirmed in our previous study. However, the critical peptides in YH and the underlying mechanisms have not been fully elucidated. This study aimed to explore the angiotensin-converting enzyme (ACE) inhibitory peptides in YH and illustrate their molecular and cellular mechanisms. The potential of YH-derived peptides was evaluated by in silico methods, followed by in vitro verification. A new competitive ACE inhibitory peptide, VIPVPFF (V7), with an IC₅₀ value of 10.27 μM, was screened. YH and V7 increased the nitric oxide (NO) levels, upregulated GUCY1A1 gene expression (approximately 15-fold), and functioned in several hypertension-related pathways in human umbilical vein endothelial cells (HUVECs). This study revealed the antihypertensive mechanisms of YH and V7, laying down a theoretical basis for their application.

Safety evaluation of high-dose intake of casein-derived peptide Met-Lys-Pro in healthy adults: A randomized, double-blind, placebo-controlled trial

Met-Lys-Pro (MKP) is a casein-derived angiotensin I-converting enzyme inhibitory peptide with the potential to cross the blood-brain barrier. It has shown preventive effects against high blood pressure (BP) and cognitive decline in animal models and human studies. MKP shows good water solubility and can be blended into a variety of foods. However, its ease of intake may contribute to the possibility of overdose. Therefore, we aimed to evaluate the safety of high-dose intake of MKP in healthy adults by conducting a randomized controlled trial with 30 subjects. Participants were randomly allocated to the MKP (n = 15) or placebo (n = 15) group. Over 4 weeks, the MKP group received test powder containing a daily dose of 1,000 μg of MKP, five times the minimum effective dose for cognitive improvement, whereas the placebo group received dextrin powder containing no detectable MKP. No clinical problems were observed in anthropometric and BP measurements or in blood and urine parameters. No adverse events owing to MKP intake were observed. These findings suggest that consumption of MKP is safe, and that it may be applicable as a safe preventive measure against hypertension and cognitive decline in future.

Techniques, perspectives, and challenges of bioactive peptide generation: A comprehensive systematic review

Due to the digestible refractory and absorbable structures of bioactive peptides (BPs), they could induce notable biological impacts on the living organism. In this regard, the current study was devoted to providing an overview regarding the available methods for BPs generation by the aid of a systematic review conducted on the published articles up to April 2019. In this context, the PubMed and Scopus databases were screened to retrieve the related publications. According to the results, although the characterization of BPs mainly has been performed using enzymatic and microbial in-vitro methods, they cannot be considered as suitable techniques for further stimulation of digestion in the gastrointestinal tract. Therefore, new approaches for both in-vivo and in-silico methods for BPs identification should be developed to overcome the obstacles that belonged to the current methods. The purpose of this review was to compile the recent analytical methods applied for studying various aspects of food-derived biopeptides, and emphasizing generation at in vitro, in vivo, and in silico.

Explorative Screening of Bioactivities Generated by Plant-Based Proteins after In Vitro Static Gastrointestinal Digestion

The gastrointestinal digestion of food proteins can generate peptides with a wide range of biological activities. In this study, we screened various potential bioactivities generated by plant-based proteins. Whey protein as an animal protein reference, five grades of pea protein, two grades of wheat protein, and potato, fava bean, and oat proteins were submitted to in vitro SGID. They were then tested in vitro for several bioactivities including measures on: (1) energy homeostasis through their ability to modulate intestinal hormone secretion, to inhibit DPP-IV activity, and to interact with opioid receptors; (2) anti-hypertensive properties through their ability to inhibit ACE activity; (3) anti-inflammatory properties in Caco-2 cells; (4) antioxidant properties through their ability to inhibit production of reactive oxygen species (ROS). Protein intestinal digestions were able to stimulate intestinal hormone secretion by enteroendocrine cells, to inhibit DPP-IV and ACE activities, to bind opioid receptors, and surprisingly, to decrease production of ROS. Neither pro- nor anti-inflammatory effects have been highlighted and some proteins lost their pro-inflammatory potential after digestion. The best candidates were pea, potato, and fava bean proteins.

Additives affect the distribution of metabolic profile, microbial communities and antibiotic resistance genes in high-moisture sweet corn kernel silage

This work investigated the effects of chemical additive vanillin (V), homofermentative Lactobacillus plantarum (LP), and heterofermentative Lactobacillus brevis (LB) on the distribution of the metabolome, microbial communities, viruses, and antibiotic-resistance genes in high-moisture corn kernel silage. LP and LB improved lactic acid production, whereas V and LB inhibited protein degradation. A significant difference was observed between the metabolite profiles of silage treated with additives and a control. In silage, the Proteobacteria and Ascomycota were the main hosts of antibiotic-resistance genes, primarily antibiotic efflux. The additives significantly affected the virus content in silage, and LB-treated silage featured the lowest virus content. Overall, these findings suggest that the application of the additive LB to high-moisture corn kernel silage impacts antibiotic-resistance gene reduction and virus distribution within the silage.

Pulses' germination and fermentation: Two bioprocessing against hypertension by releasing ACE inhibitory peptides

Angiotensin-Converting Enzyme (ACE) is one of the main blood pressure regulators in the renin-angiotensin system leading to hypertension. Hypertension is known as the modern world disease which increases the risk of serious human health problems. Synthetic drugs and some natural compounds could treat this disease by binding to ACE and reducing its activity. Pulses, one of the legumes group, that are the rich in protein sources in the human diet, have several bioactive compounds with ACE inhibitory (ACE I) properties. However, several processes need to break down proteins and improve ACE I activity in foods. Germination and fermentation, known by bioprocessing, could make releasing bioactive peptides and polyphenols and exhibit ACE I and either other health properties such as antimicrobial, antioxidant, anti-diabetic and anticancer activities. Various factors such as kind of selective culture, temperature, time and humidity affect these processes. This review summarizes relevant studies about the effect of pulses' germination and fermentation to produce ACE I activity compounds and also explains about main parameters affecting the health properties of these two bioprocessing to treat hypertension that could lead to the development of their application in pharmaceuticals instead of synthetic drugs.

Characteristics of Potential Protein Nutraceuticals of Plant Origin with Antioxidant Activity

This study used selected plant proteins and the tools available in the BIOPEP-UWM database to profile proteins and release antioxidant nutraceuticals from their primary structures. The frequency of the occurrence of fragments with antioxidant activity in a protein sequence (the A parameter) was determined. A simulated monocatalytic proteolysis was carried out using ficin or stem bromelain or pepsin (pH > 2), and the theoretical degree of hydrolysis (DHt) and the frequency (including relative frequency) of the release of fragments with a particular antioxidant activity by a selected enzyme (the AE and W parameters, respectively). Both barley hordoindolines and the protein group of "actins and other rice proteins" were characterised by the best antioxidant potential. On the other hand, among the main analysed cereal protein groups or species, the best nutraceutical sources included kafirins, rice glutelins and α-gliadins. Potentially the most nutraceutical molecules were released by pepsin (HL, VY, PHQ and PWQ biopeptides) from gliadins, but the most analysed proteins were hydrolysed (66% on average) and the DHt for ficin and bromelain amounted to 27% and 31%, respectively. However, based on the calculated AE mean values, it can be concluded that nutraceuticals were more frequently released from rice protein structures (IY and VY biopeptides), and less frequently released from barley and other cereal protein species, which may be of significance in the context of designing nutraceutical food.