Germination of Phaseolus vulgaris and alcalase hydrolysis of its proteins produced bioactive peptides capable of improving markers related to type-2 diabetes in vitro

Modifying of non-nutritional compounds in legumes: Processing strategies and new technologies

Legumes are consumed worldwide, are notable for their nutritional quality, however, contain certain non-nutritional compounds (NNCs) that can affect the absorption of nutrients, though these may exhibit bioactive properties. Various processing methods can modify the concentration of NNCs, including soaking and germination. These methods can be combined with other thermal, non-thermal, and bioprocessing treatments to enhance their efficiency. The efficacy of these methods is contingent upon the specific types of NNCs and legume in question. This work examines the effectiveness of these processing methods in terms of modifying the concentration of NNCs present in legumes as well as the potential use of emerging technologies, to enhance the level of NNCs modification in legumes. These technologies could increase the functional use of legume flours, potentially leading to new opportunities for incorporating legume-based ingredients in a range of culinary applications, thereby enhancing the diets of many individuals worldwide.

Precooked Jack Bean [Canavalia ensiformis (L.) DC] Sprout: Generation of Dipeptidyl Peptidase-IV Inhibitory Peptides during Simulated Digestion

Bioactive peptides generated from jack bean sprouts are reported to function as dipeptidyl peptidase IV (DPP-IV) inhibitors. However, no studies have investigated the effect of precooking followed by simulated digestion using pepsin-pancreatin to increase DPP-IV inhibitory peptide generation in jack bean sprouts. Therefore, the present study aimed to explore the generation of DPP-IV inhibitory peptides from precooked jack bean [Canavalia ensiformis (L.) DC] sprouts during simulated digestion with pepsin-pancreatin. The results showed that peptide fractions of the sample hydrolysate with molecular weight <1 kDa exhibited the strongest DPP-IV inhibitory activity (84.77%±0.49%) after simulated digestion. This activity was slightly greater than that (74.12%±0.85%) observed prior to simulated digestion. These findings demonstrate that the DPP-IV inhibitory activity of precooked jack bean sprouts can be retained following simulated digestion. Moreover, our investigation revealed the sequences of two novel peptides following simulated digestion with critical amino acids. The presence of alanine and glycine at the penultimate N-terminus of AAGPKP and LGDLLK confirmed the presence of DPP-IV inhibitors. Both peptide sequences are nontoxic and interact with the catalytic sites of enzymes through hydrogen bonds.

Enrichment and Quantitation of Dipeptidyl Peptidase IV Inhibitory Peptides in Quinoa upon Systematic Malting

Food-derived peptides with an inhibitory effect on dipeptidyl peptidase IV (DPP-IV) can be used as an additive treatment for type 2 diabetes. The inhibitory potential of food depends on technological protein hydrolysis and gastrointestinal digestion, as the peptides only act after intestinal resorption. The effect of malting as a hydrolytic step on the availability of these peptides in grains has yet to be investigated. In this study, quinoa was malted under systematic temperature, moisture, and time variations. In the resulting malts, the DPP-IV inhibition reached a maximum of 45.02 (±10.28) %, whereas the highest overall concentration of literature-known inhibitory peptides was 4.07 μmol/L, depending on the malting parameters. After in vitro gastrointestinal digest, the inhibition of most malts, as well as the overall concentration of inhibitory peptides, could be increased significantly. Additionally, the digested malts showed higher values in both the inhibition and the peptide concentration than the unmalted quinoa. Concerning the malting parameters, germination time had the highest impact on the inhibition and the peptide concentration after digest. An analysis of the protein sizes before and after malting gave first hints toward the origin of these peptides, or their precursors, in quinoa.

Physio-biochemical responses and crop performance analysis in chickpea upon botanical priming

Chickpea is a highly nutritious protein-rich source and one of the major crops to alleviate global malnutrition, but poor seed quality affects its productivity. Seed quality is essential for better crop establishment and higher yields, particularly in the uncertain climate change. The present study investigated the impact of botanical priming versus hydropriming and bavistin seed treatment on chickpea seeds. A detailed physiological (germination percentage, root and shoot length, vigour index) and biochemical (amylase, protease, dehydrogenase, phytase, and lipid peroxidation) analysis was carried out in order to assess the effect of priming treatments. Turmeric-primed seeds showed better germination rate (94.5%), seedling length, enzyme activity, and lower malondialdehyde (MDA) content. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed the expression of minor polypeptides of albumin and globulin in the primed seeds. Moreover, field experiments indicated increased crop growth, vigour, days to 50% flowering, yield and its attributing traits in turmeric-primed seeds. Botanical priming can increase chickpea yield by up to 16% over the control group. This low-cost and eco-friendly technique enhances seed and crop performance, making it a powerful tool for augmenting chickpea growth. Therefore, chickpea growers must adopt botanical priming techniques to enhance the quality of seed and crop performance. Moreover, this approach is environmentally sustainable and can help conserve natural resources in the long term. Therefore, this new approach must be widely adopted across the agricultural industry to ensure sustainable and profitable farming practices.

Effects of Germination on the Structure, Functional Properties, and In Vitro Digestibility of a Black Bean (Glycine max (L.) Merr.) Protein Isolate

The utilization of black beans as a protein-rich ingredient presents remarkable prospects in the protein food industry. The objective of this study was to assess the impact of germination treatment on the physicochemical, structural, and functional characteristics of a black bean protein isolate. The findings indicate that germination resulted in an increase in both the total and soluble protein contents of black beans, while SDS-PAGE demonstrated an increase in the proportion of 11S and 7S globulin subunits. After germination, the particle size of the black bean protein isolate decreased in the solution, while the absolute value of the zeta potential increased. The above results show that the stability of the solution was improved. The contents of β-sheet and β-turn gradually decreased, while the content of α-helix increased, and the fluorescence spectrum of the black bean protein isolate showed a red shift phenomenon, indicating that the structure of the protein isolate and its polypeptide chain were prolonged, and the foaming property, emulsification property and in vitro digestibility were significantly improved after germination. Therefore, germination not only improves functional properties, but also nutritional content.

Germinated chickpea protein ficin hydrolysate and its peptides inhibited glucose uptake and affected the bitter receptor signaling pathway in vitro

The objective of this study was to evaluate germinated chickpea protein hydrolysate (GCPH) in vitro for its effect on markers of type 2 diabetes (T2D) and bitter taste receptor expression in intestinal epithelial cells. Protein hydrolysate was obtained using ficin, and the resulting peptides were sequenced using LC-ESI-MS/MS. Caco-2 cells were used to determine glucose uptake and extra-oral bitter receptor activation. Three peptides, VVFW, GEAGR, and FDLPAL, were identified in legumin. FDLPAL was the most potent peptide in molecular docking studies with a DPP-IV energy of affinity of -9.8 kcal mol-1. GCPH significantly inhibited DPP-IV production by Caco-2 cells (IC50 = 2.1 mM). Glucose uptake was inhibited in a dose-dependent manner (IC25 = 2.0 mM). A negative correlation was found between glucose uptake and PLCβ2 expression in Caco-2 cells (R value, -0.62). Thus, GCPH has the potential to be commercialized as a functional ingredient.

Impact of thermal treatments and simulated gastrointestinal digestion on the α-amylase inhibitory activity of different legumes

Legumes are excellent sources of proteins that can be hydrolysed to generate antidiabetic peptides, which inhibit carbohydrate digestive enzymes. The degree of protein hydrolysis depends on the thermal treatment applied and how it impacts protein denaturation and thus accessibility to enzymes. In this study, α-amylase inhibitory activities of cooked (conventional, pressure, and microwave cooking) and digested (simulated gastrointestinal digestion, GID) green pea, chickpea, and navy beans were evaluated, together with the impact of thermal treatments on peptide profiles after GID. All peptides extracts inhibited α-amylase after cooking and GID, and the peptide fraction <3 kDa was responsible for main activity. In green peas and navy beans, microwave cooking showed the highest impact whereas none thermal treatment highlighted in chickpeas. The peptidomics analysis of the fractions <3 kDa identified a total of 205 peptides, 43 of which were found to be potentially bioactive according to in silico analysis. Also quantitative results evidenced differences in the peptide profile between the type of legume and thermal treatment.

Legume-Derived Bioactive Peptides in Type 2 Diabetes: Opportunities and Challenges

Diabetes mellitus is a complex disorder characterized by insufficient insulin production or insulin resistance, which results in a lifelong dependence on glucose-lowering drugs for almost all patients. During the fight with diabetes, researchers are always thinking about what characteristics the ideal hypoglycemic drugs should have. From the point of view of the drugs, they should maintain effective control of blood sugar, have a very low risk of hypoglycemia, not increase or decrease body weight, improve β-cell function, and delay disease progression. Recently, the advent of oral peptide drugs, such as semaglutide, brings exciting hope to patients with chronic diabetes. Legumes, as an excellent source of protein, peptides, and phytochemicals, have played significant roles in human health throughout human history. Some legume-derived peptides with encouraging anti-diabetic potential have been gradually reported over the last two decades. Their hypoglycemic mechanisms have also been clarified at some classic diabetes treatment targets, such as the insulin receptor signaling pathway or other related pathways involved in the progress of diabetes, and key enzymes including α-amylase, α-glucosidase, and dipeptidyl peptidase-IV (DPP-4). This review summarizes the anti-diabetic activities and mechanisms of peptides from legumes and discusses the prospects of these peptide-based drugs in type 2 diabetes (T2D) management.

In Vitro Assessment Methods for Antidiabetic Peptides from Legumes: A Review

Almost 65% of the human protein supply in the world originates from plants, with legumes being one of the highest contributors, comprising between 20 and 40% of the protein supply. Bioactive peptides from various food sources including legumes have been reported to show efficacy in modulating starch digestion and glucose absorption. This paper will provide a comprehensive review on recent in vitro studies that have been performed on leguminous antidiabetic peptides, focusing on the α-amylase inhibitor, α-glucosidase inhibitor, and dipeptidyl peptidase-IV (DPP-IV) inhibitor. Variations in legume cultivars and methods affect the release of peptides. Different methods have been used, such as in sample preparation, including fermentation (t, T), germination (t), and pre-cooking; in protein extraction, alkaline extraction, isoelectric precipitation, phosphate buffer extraction, and water extraction; in protein hydrolysis enzyme types and combination, enzyme substrate ratio, pH, and time; and in enzyme inhibitory assays, positive control type and concentration, inhibitor or peptide concentration, and the unit of inhibitory activity. The categorization of the relative scale of inhibitory activities among legume samples becomes difficult because of these method differences. Peptide sequences in samples were identified by means of HPLC/MS. Software and online tools were used in bioactivity prediction and computational modelling. The identification of the types and locations of chemical interactions between the inhibitor peptides and enzymes and the type of enzyme inhibition were achieved through computational modelling and enzyme kinetic studies.

Bioactive and health-promoting properties of enzymatic hydrolysates of legume proteins: a review

This study comprehensively reviewed the effect of controlled enzymatic hydrolysis on the bioactivity of pulse protein hydrolysates (PPHs). Proteolysis results in the partial structural unfolding of pulse proteins with an increase in buried hydrophobic groups of peptide sequences. The use of PPHs in a dose-dependent manner can enhance free radical scavenging and improve antioxidant activities regarding inhibition of lipid oxidation, ferric reducing power, metal ion chelation, and β-carotene bleaching inhibition. Ultrafiltered peptide fractions with low molecular weights imparted angiotensin-I converting enzyme (ACE) inhibitory effects during in vitro simulated gastrointestinal digestion and in vivo conditions. Ultrasonication, high-pressure pretreatments, and glycosylation as post-treatments can improve the antiradical, antioxidant, and ACE inhibitory activities of PPHs. The electrostatic attachment of pulse peptides to microbial cells can inhibit the growth and activity of bacteria and fungi. Bioactive pulse peptides can reduce serum cholesterol and triglycerides, and inhibit the formation of adipocyte lipid storage, allergenic factors, inflammatory markers, and arterial thrombus without cytotoxicity. The combination of germination and enzymatic hydrolysis can significantly increase the protein digestibility and bioavailability of essential amino acids. Moreover, the utilization and enrichment of bakery and meat products with functional PPHs ensure quality, safety, and health aspects of food products.

Biological functions of peptides from legumes in gastrointestinal health. A review legume peptides with gastrointestinal protection

Extensively consumed worldwide, legumes such as beans, soybeans, chickpeas, and peas represent a great source of protein. Legume-derived proteins provide bioactive peptides, small sequences of amino acids produced by enzymatic hydrolysis, gastrointestinal digestion, fermentation, or germination. Recent studies showed diverse biological effects of these peptides as antioxidants, antihypertensives, anti-inflammatory, antimicrobial, antithrombotic, antidiabetic, hypocholesterolemic, and even immunomodulators. These beneficial effects aid in preventing and treating chronic illnesses, particularly inflammatory disorders, obesity, and cardiovascular diseases. Thus, this work discusses these biological functions in gastrointestinal digestion health of bioactive peptides obtained from common beans, soybeans, chickpeas, peas, and other legumes. PRACTICAL APPLICATIONS: Knowledge of the nutraceutical properties of legumes can encourage the use of these seeds as ingredients in the development and design of functional foods.

Diabetes and seeds: New horizon to promote human nutrition and anti-diabetics compounds in grains by germination

Type 2 diabetes (T2D) is a complex and heterogeneous chronic metabolic disorder disease that is associated with high blood sugar. Because of the side effects of synthetic drugs on T2D patients and their economic burden, interest in plant-derived functional foods like grains with biological activities has developed. Based on scientific reports, whole grains are rich sources of energy, nutrients, and bioactive compounds and are assumed to have beneficial health effects on glucose enzymes regulation or hyperglycemia. Nowadays, different methods have been applied to enhance whole seed healthful properties and anti-diabetic compounds, and germination is one of them. Germination (sprouting) is a cost-effective method for boosting the activity of endogenous seed enzymes and modifying the structure of macromolecules. Some of these macromolecules like bioactive peptides, polyphenols, dietary fiber, and vitamins are related to diabetes management. Determining the best germination condition can help to promote these anti-diabetics properties of compounds. This study presents relevant information about diabetes, the effect of seed germination on releasing bioactive compounds, and optimizing environmental germination conditions to improve the anti-diabetic compounds in seeds for reaching functional food.

A comprehensive review on the glucoregulatory properties of food-derived bioactive peptides

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with antidiabetic properties. Notable examples include AGFAGDDAPR, a black tea-derived peptide, VRIRLLQRFNKRS, a β-conglycinin-derived peptide, and milk-derived peptide VPP, which have shown antidiabetic effects in diabetic rodent models through variety of pathways including improving beta-cells function, suppression of alpha-cells proliferation, inhibiting food intake, increasing portal cholecystokinin concentration, enhancing insulin signaling and glucose uptake, and ameliorating adipose tissue inflammation. Despite the immense research on glucoregulatory properties of bioactive peptides, incorporation of these bioactive peptides in functional foods or nutraceuticals is widely limited due to the existence of several challenges in the field of peptide research and commercialization. Ongoing research in this field, however, is fundamental to pave the road for this purpose.

Impact of germination time on protein solubility and anti-inflammatory properties of Pisum sativum L grains

•

Germination has an evident impact on the amount of soluble protein in sprouts.

•

The amount of soluble protein can be correlated with the presence of biopeptides.

•

In vitro assays indicate that sprouts soluble protein act as anti-inflammatory agents.

•

Pisum sativum sprouts may constitute a minimally processed functional food.

•

Proteins and peptides isolated from sprouts could be used as nutraceutical ingredients.

During germination processes take place that modify the major components of the grain, such is the case of proteins that are hydrolyzed to generate peptides that can lead to the generation of bioactivity. The objective of the present work was to germinate grains of Pisum sativum to evaluate the effect on the soluble protein content and the anti-inflammatory activity. The grains were subjected to 10 days of germination at 24 °C and relative humidity of 75%. Sprouts were lyophilized, milled, and phenolic compounds were extracted to avoid interferences. Soluble protein content varied significantly during the 10 days of germination. In vitro assays indicate that sprouts protein inhibits thermal denaturation of proteins, protease activity, and stabilize cell membranes. The IC50 values indicate that after germination the bioactivity increased between 1.4 and 3.5 times, with respect to the ungerminated grains. Results indicated that Pisum sativum sprouts may constitute promising health-promoting foods.

Sensory and Biological Potential of Encapsulated Common Bean Protein Hydrolysates Incorporated in a Greek-Style Yogurt Matrix

The work aimed to develop a gel as a protective barrier of common bean protein hydrolysates to be incorporated into a Greek-style yogurt and evaluate the sensory perception and biological potential. The gel was formed by complex coacervation and induced heat at a pH 3.5 and 3:1 biopolymer ratio (whey protein and gum arabic). The gel presented a 39.33% yield, low syneresis (0.37%), and a gel strength of 100 gf. The rheological properties showed an elastic behavior (G′ > G″). The gel with the most stable characteristics favored the incorporation of 2.3 g of hydrolysates to be added into the Greek-style yogurt. Nutritionally, the Greek-style yogurt with the encapsulated hydrolysates presented 9.96% protein, 2.27% fat, and 1.76% carbohydrate. Syneresis (4.64%), titratable acidity (1.39%), and viscoelastic behavior presented similar characteristics to the Greek-style control yogurt. The bitterness and astringency in yogurt with encapsulated hydrolysates decreased 44% and 52%, respectively, compared to the yogurt control with the unencapsulated hydrolysates. The Greek-style yogurt with the encapsulated hydrolysates showed the ability to inhibit enzymes related to carbohydrate metabolism (α-amylase (92.47%) and dipeptidyl peptidase-4 (75.24%) after simulated gastrointestinal digestion). The use of gels could be an alternative to transporting, delivering, and masking off-flavors of common bean protein hydrolysates in food matrices to decrease glucose absorption for type 2 diabetes patients.

A review on processing methods and functions of wheat germ-derived bioactive peptides

Wheat germ protein is a potential resource to produce bioactive peptides. As a cheap, safe, and healthy nutritional factor, wheat germ-derived bioactive peptides (WGBPs) provide benefits and great potential for biomedical applications. The objective of this review is to reveal the current research status of WGBPs, including their preparation methods and biological functions, such as antibacterial, anti-tumor, immune regulation, antioxidant, and anti-inflammatory properties, etc. We also reviewed the information in terms of the preventive ability of WGBPs to treat serious infectious diseases, to offer their reference to further research and application. Opinions on future research directions are also discussed. Through the review of previous research, we find that there are still some scientific issues in the basic research and industrialization process of WGBPs that deserve further exploration. Firstly, based on current complex enzymolysis, the preparation and production of WGBPs need to be combined with other advanced technology to achieve efficient and large-scale production. Secondly, studies on the bioavailability, biosafety, and mechanism against different diseases of WGBPs need to be carried out in different in vitro and in vivo models. More human experimental evidence is also required to support its industrial application as a functional food and nutritional supplement.HighlightsThe purification and identification of wheat germ-derived bioactive peptides.The main biological activities and potential mechanisms of wheat germ hydrolysates/peptides.Possible absorption and transport pathways of wheat germ hydrolysate/peptide.Wheat germ peptide shows a variety of health benefits according to its amino acid sequence.Current food applications and future perspectives of wheat germ protein hydrolysates/peptide.

Production, Purification, and Potential Health Applications of Edible Seeds' Bioactive Peptides: A Concise Review

Edible seeds play a significant role in contributing essential nutritional needs and impart several health benefits to improve the quality of human life. Previous literature evidence has confirmed that edible seed proteins, their enzymatic hydrolysates, and bioactive peptides (BAPs) have proven and potential attributes to ameliorate numerous chronic disorders through the modulation of activities of several molecular markers. Edible seed-derived proteins and peptides have gained much interest from researchers worldwide as ingredients to formulate therapeutic functional foods and nutraceuticals. In this review, four main methods are discussed (enzymatic hydrolysis, gastrointestinal digestion, fermentation, and genetic engineering) that are used for the production of BAPs, including their purification and characterization. This article’s main aim is to provide current knowledge regarding several health-promoting properties of edible seed BAPs in terms of antihypertensive, anti-cancer, antioxidative, anti-inflammatory, and hypoglycemic activities.

Effect of Food Processing on Antioxidant Potential, Availability, and Bioavailability

Antioxidants are understood to play a key role in disease prevention; because of this, research and interest in these compounds are ever increasing. Antioxidative phytochemicals from natural sources are preferred, as some negative implications have been associated with synthetic antioxidants. Beans, nuts, seeds, fruits, and vegetables, to name a few, are important sources of phytochemicals, which have purported health benefits. The aforementioned plant sources are reportedly rich in bioactive compounds, most of which undergo some form of processing (boiling, steaming, soaking) prior to consumption. This article briefly reviews selected plants (beans, nuts, seeds, fruits, and vegetables) and the effects of processing on the antioxidant potential, availability, and bioavailability of phytochemicals, with research from our laboratory and other studies determining the health benefits of and processing effects on bioactive compounds.

Proteins and peptides from vegetable food sources as therapeutic adjuvants for the type 2 diabetes mellitus

Proteins and peptides are fundamental components of the cereals, pseudocereals, and legumes, giving them numerous health-beneficial properties. Previous studies have demonstrated that these molecules exerted effects on current therapeutic targets related to type 2 diabetes mellitus, such as incretin hormones (responsible for appetite suppression), dipeptidyl peptidase IV (an enzyme involved in the inactivation and degradation of the incretin hormones), and glucose transporters (molecules that transport glucose in or out of cells). Therefore, this review presents the current biological activity of protein derivatives and peptides isolated from cereals, pseudocereals, and legumes on these therapeutic markers, highlighting their potential as a possible pharmacological treatment for type 2 diabetes mellitus.

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.

Antioxidant and Anti-Inflammatory Potential of Peptides Derived from In Vitro Gastrointestinal Digestion of Germinated and Heat-Treated Foxtail Millet (Setaria italica) Proteins

This study aimed at identifying antioxidant and anti-inflammatory peptides derived from the in vitro gastrointestinal digestion of germinated and heated (microwave and boiling) foxtail millet. The protein digest fraction containing low-molecular-weight peptides (<3 kDa) and the most hydrophobic subfraction (F4) abundant in random coil structure were responsible for the bioactivity. Then, seven novel peptides were identified using liquid chromatography with tandem mass spectrometry (LC-MS/MS) from the most potent F4 subfraction derived from boiled germinated millet. All seven synthesized peptides significantly (p < 0.05) reduced reactive oxygen species production and increased glutathione content and superoxide dismutase activity in Caco-2 cells, whereas two peptides (EDDQMDPMAK and QNWDFCEAWEPCF) were superior in inhibiting nitric oxide, tumor necrosis factor-α (reduced to 42.29 and 44.07%, respectively), and interleukin-6 (reduced to 56.59 and 43.45%, respectively) production in a RAW 264.7 cell model. This study is the first to report about the potential role of germinated and heated foxtail millet as a source of dual antioxidant and anti-inflammatory peptides.

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.

Bioactive peptides from beans with the potential to decrease the risk of developing noncommunicable chronic diseases

Several studies have demonstrated that peptides obtained from the proteins of different bean species have the potential to act on therapeutic targets of noncommunicable chronic diseases or NCDs. However, peptides with great structural diversity can be obtained from the hydrolysis of proteins present in foods. Therefore, the present review had the objective of identifying, in silico, the possibility of obtaining peptides with potential biological activity from the storage globulin proteins of the bean species Phaseolus vulgaris (L.), Vigna angularis (Willd.), Vigna radiata (L.) and Vigna unguiculata (L.) Walp., using the UniProtKB, BIOPEP and PeptideRanker databases, as well as reviewing available research reports that showed evidence bioactive properties of peptides obtained from beans via in vitro assays. For all the species studied, the highest frequency of the occurrence of bioactive fragments was found for the inhibition of dipeptidyl peptidase-IV, followed by the inhibition of the angiotensin-converting enzyme and by antioxidant activity. The inhibition of the two enzymes is the therapeutic target of drugs used for type 2 diabetes mellitus (T2DM) and for hypertension, respectively, while the antioxidant activity can prevent the development of several chronic diseases related to oxidative stress.

Effect of Instant Controlled Pressure-Drop (DIC), Cooking and Germination on Non-Nutritional Factors of Common Vetch (Vicia sativa spp.)

Legumes are widely consumed by humans, being an important source of nutrients; however, they contain non-nutritional factors (NNFs), such as phytic acid (IP6), raffinose, stachyose, total phenolic compounds, condensed tannins, and flavonoids, that have negative effects on human health. Although vetches (Vicia sativa) are widely cultivated, they are not intended for human feeding due to their contents of NNF. Usually, the NNF are removed by cooking or germinating; however, germination is a process that requires extended time, and cooking may compromise the viability of some nutrients. To promote vetches for human consumption, the effect of the Instant Controlled Pressure Drop (DIC) process was studied as an alternative to cooking and germinating to decrease NNF contents. Results showed that compared to raw vetches, DIC treatment reduced total phenolic compounds (48%), condensed tannins (28%), flavonoids (65%), IP6 (92%), raffinose (77%), and stachyose (92%). These results are very similar to the ones achieved by traditional ways of removing NNF.

Bioactive proteins and phytochemicals from legumes: Mechanisms of action preventing obesity and type-2 diabetes

The Fabaceae family of plants include a variety of seeds with multiple shapes, sizes, and colors; with a great diversity of bioactive compounds found in legume seeds. Legumes are an excellent source of protein, peptides and phytochemicals which are present in significant amounts. These bioactive compounds have been reported to reduce the risk of developing non-communicable diseases (NCD), such as obesity and type-2 diabetes. In this narrative review, we discuss the biological potential of bioactive compounds found in legumes and the health benefits associated with their consumption as an alternative approach in the management of NCD. Current extraction methods, characteristics of the bioactive compounds, and different in vitro and in vivo studies evaluating the bioactivity of legume bioactives are reviewed and discussed.

Production of White, Red and Black Quinoa (Chenopodium quinoa Willd Var. Real) Protein Isolates and Its Hydrolysates in Germinated and Non-Germinated Quinoa Samples and Antioxidant Activity Evaluation

Red, black and white seeds quinoa were germinated at 28 °C during 24 (G1), 48 and 72 h (G3). Red quinoa presented a higher percentage of germination with a value of 46% of germination at 72 h. Quinoa protein isolate (QPI) was obtained by alkaline extraction (pH 8.0) followed by an isoelectric precipitation (pH 4.5) from white, red and black quinoa seeds, germinated QPI-G1 or QPI-G3 and non-germinated QPI-NG, Chenopodium quinoa Willd var. Real. QPI-G1, QPI-G3 and QPI-NG were subject to a simulated gastric digestion (DG) and in vitro duodenal digestion (DD). The antioxidant activity was evaluated using the 1, 1-diphenyl-2-picryl hydrazyl (DPPH), azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC) methods. Gastric and duodenal digest of QPI-NG and QPI-G1 and QPI-G3 from white, red and black quinoa presented antioxidant activity. QPI-G1-DD of white quinoa presented the highest antioxidant activity with a DPPH value of 167.98 µmoL TE/g of digest, QPI-G1-DD of red quinoa with an ABTS value of 204.86 µmoL TE/g of digest and QPI-G1-DD of black quinoa with an ORAC value of 401.42 µmoL TE/g of digest. QPI-G3-DD of white quinoa presented higher antioxidant activity with a DPPH value of 186.28 µmoL TE/g of sample, QPI-G3-DD of red quinoa with an ABTS value of 144.06 µmoL TE/g of digest and QPI-G3-DD of black quinoa with an ORAC value of 395.14 µmoL TE/g of digest. The inhibition of reactive oxygen species (ROS) production in the zebrafish embryo model (Danio rerio) was evaluated. Protein profiles of QPI from white, red and black from germinated quinoa and non-germinated quinoa were similar with proteins between 10 kDa to 100 kDa with the presence of globulins 11S and 7S and 2S albumins.

Antihyperglycemic and hypoglycemic activity of naturally occurring peptides and protein hydrolysates from easy-to-cook and hard-to-cook beans (Phaseolus vulgaris L.)

The present study was undertaken to examine the antidiabetic potential of naturally occurring peptides and hydrolysate fractions from easy-to-cook (ETC) and hard-to-cook (HTC) beans. All fractions were tested regarding their in vitro inhibitory activities against α-amylase and α-glucosidase as well as in vivo anti-hyperglycemic and hypoglycemic effects. Results evidenced that the peptide fractions with the lowest molecular weight (<3 kDa) have the highest inhibitory activities, and a 16.9%-89.1% inhibition of α-amylase and 34.4%-89.2% inhibition of α-glucosidase were observed. Regarding the antihyperglycemic activity, the fraction ETCNO3-10 showed a better performance than the positive control (acarbose). In addition, results from hypoglycemic activity evidenced that the tested peptide fractions were able to decrease the glucose levels at the same extension of glibenclamide, maintaining a constant basal glucose level without a postprandial hyperglycemia peak. Finally, it is possible to suggest that the naturally occurring peptides and hydrolysate fractions obtained from ETC and HTC common beans could be used in functional food production or pharmaceutical formulations to prevent diabetes.

Recently isolated antidiabetic hydrolysates and peptides from multiple food sources: a review

Diabetes, a metabolic syndrome of global importance has been on a progressive rise in recent years. Several pharmacological approaches have been made, which have proved effective, but with underlying side effects. Bioactive hydrolysates (BHs) and peptides (BPs) from food sources, however, have shown the relative advantage of imparting less adverse effects. Furthermore, BHs and BPs from food have been discovered to impart their antidiabetic potentials through one or more mechanisms such as inhibition of digestive enzymes, inhibition of the antigenic enzyme - Dipeptyl peptidase IV (DPP-IV), decrease in blood glucose levels and increase in insulin uptake. Several plants and animal sources have been used as protein sources for the isolation of antidiabetic hydrolysates and peptides through different mechanisms and analytical techniques. This review integrates recent research information about several popular and unconventional food sources of BHs and BPs, their isolation techniques, antidiabetic effects and protein profiles. In addition, the fractionation technique(s) employed in each study and inhibition potentials of BHs and BPs are reviewed. This article is intended to supplement accessible scholarly literature and intellectual awareness on the subject of food-oriented approach for the management of diabetes.

Extraction and identification of α-amylase inhibitor peptides from Nephelium lappacheum and Nephelium mutabile seed protein using gastro-digestive enzymes

The potential of N. lappacheum and N. mutabile seed as a source of α-amylase inhibitor peptides was explored based on the local traditional practice of using the seed. Different gastro-digestive enzymes (i.e. pepsin or chymotrypsin) or a sequential digestion were used to extract the peptides. The effects of digestion time and enzyme to substrate (E:S) ratio on the α-amylase inhibitory activity were investigated. Results showed that chymotrypsin was effective in producing the inhibitor peptides from rambutan seed protein at E:S ratio 1:20 for 1 h, whereas pepsin was more effective for pulasan seed protein under the same condition. A total of 20 and 31 novel inhibitor peptides were identified, respectively. These peptides could bind with the subsites of α-amylase (i.e. Trp58, Trp59, Tyr62, Asp96, Arg195, Asp197, Glu233, His299, Asp300, and His305) and formed a sliding barrier that preventing the formation of enzyme/substrate intermediate leading to lower α-amylase activity.

Peptides derived from in vitro gastrointestinal digestion of germinated soybean proteins inhibit human colon cancer cells proliferation and inflammation

The aim was to investigate the potential of germinated soybean proteins asa source of peptides with anticancer and anti-inflammatory activities produced after simulated gastrointestinal digestion. Protein concentrate from germinated soybean was hydrolysed with pepsin/pancreatin and fractionated by ultrafiltration. Whole digest and fractions>10, 5-10, and<5kDa caused cytotoxicity to Caco-2, HT-29, HCT-116 human colon cancer cells, and reduced inflammatory response caused by lipopolysaccharide in macrophages RAW 264.7. Antiproliferative and anti-inflammatory effects were generally higher in 5-10kDa fractions. This fraction was further purified by semi-preparative chromatography and characterised by HPLC-MS/MS. The most potent fraction was mainly composed of β-conglycinin and glycinin fragments rich in glutamine. This is the first report on the anti-cancer and anti-inflammatory effects of newly isolated and identified peptides from germinated soybean released during gastrointestinal digestion. These findings highlight the potential of germination as a process to obtain functional foods or nutraceuticals for colon cancer prevention.

Characterization of peptides from common bean protein isolates and their potential to inhibit markers of type-2 diabetes, hypertension and oxidative stress

BACKGROUND

Diabetes and hypertension are diseases affecting a high proportion of the world population; the use of food-based products such as common bean peptides may contribute to reduce the risk of complications associated to chronic diseases. The aim was to produce and characterize peptides from common bean protein isolates and evaluate their potential to inhibit markers of type-2 diabetes, hypertension and oxidative stress.

RESULTS

Mexican black and Brazilian Carioca bean isolated proteins were characterized after pepsin/pancreatin digestion. Also, four synthesized pure peptides, originally found in these beans, were evaluated. Bean protein digests and pure peptides exerted dipeptidyl peptidase-IV (DPP-IV) inhibition (IC₅₀ = 0.03-0.87 mg dry weight (DW) mL^-1 ). Lineweaver-Burk plots and computational modeling showed competitive inhibition of DPP-IV. Angiotensin-converting enzyme (ACE) inhibition ranged from IC₅₀ = 0.09 to 0.99 mg DW mL^-1 , and α-glucosidase inhibition ranged from 36.3 to 50.1% mg^-1 DW. Carioca Perola bean digested proteins presented the highest antioxidant capacity (269.3 mmol L^-1 Trolox equivalent g^-1 DW) as the peptide KTYGL (P > 0.05) with the most potent DPP-IV and ACE inhibition.

CONCLUSION

Peptides from common bean have antidiabetic and antihypertensive potential regardless of their antioxidant capacity. © 2016 Society of Chemical Industry.

Optimization of enzymatic production of anti-diabetic peptides from black bean (Phaseolus vulgaris L.) proteins, their characterization and biological potential

The aim was to optimize the production of bioactive peptides from black bean (Phaseolus vulgaris L.) protein isolate and to determine their biological potential using biochemical and in silico approaches. Protein fractions were generated using eight commercially available proteases after 2, 3 and 4 h and 1:20, 1:30 and 1:50 enzyme/substrate (E/S) ratios. The best combination of conditions to generate anti-diabetic peptides was with alcalase for 2 h and E/S of 1:20; with inhibition values for dipeptidyl peptidase IV (DPP-IV, 96.7%), α-amylase (53.4%) and α-glucosidase (66.1%). Generated peptides were characterized using LC-ESI-MS/MS. Molecular docking analysis was performed to predict individual peptide biological potential using DockingServer®. Peptides EGLELLLLLLAG, AKSPLF and FEELN inhibited DPP-IV more efficiently in silico through free energy interactions of -9.8, -9.6 and -9.5 kcal mol(-1), respectively, than the control sitagliptin (-8.67 kcal mol(-1)). The peptide TTGGKGGK (-8.97 kcal mol(-1)) had higher inhibitory potential on α-glucosidase compared to the control acarbose (-8.79 kcal mol(-1)). Peptides AKSPLF (-10.2 kcal mol(-1)) and WEVM (-10.1 kcal mol(-1)) generated a lower free energy interaction with the catalytic site of α-amylase in comparison with acarbose (-9.71 kcal mol(-1)). Bean peptides inhibited the tested enzymes through hydrogen bonds, polar and hydrophobic interactions. The main bindings on the catalytic site were with ASP192, GLU192 and ARG 253 on DPP-IV; TYR151, HIS201 and ILE235 on α-amylase; and ASP34, THR83 and ASN32 on α-glucosidase. For the first time, a systematic evaluation and characterization of the anti-diabetic peptides from black bean protein isolate is presented with the potential for inhibiting important molecular markers related to diabetes.

Changes in antioxidant and antiinflammatory activity of black bean (Phaseolus vulgaris L.) protein isolates due to germination and enzymatic digestion

Germination is an inexpensive process to improve the nutritional properties of legumes. The effect of germinating black bean seeds on the production of cotyledon protein hydrolysates (CPH) with antioxidant and antiinflammatory activities was analyzed in this research. After simulated enzymatic digestion, the oxygen radical absorbance capacity (ORAC) of CPH obtained from germinated black beans was lower than that observed for raw cotyledons. There were no significant differences among CPH cellular antioxidant activities (CAA), except for the high CAA of the 120 min hydrolysate obtained from one day germinated black bean cotyledons. The most significant changes due to germination and enzymatic hydrolysis were observed for the inhibition of nitric oxide (NO) production in macrophages. The NO synthesis inhibition observed for raw CPH was reduced after simulated gastrointestinal digestion but for germinated samples the inhibition was doubled. Peptides derived from cell wall proteins produced during germination could be responsible of antiinflammatory activity.