Chickpea Protein Hydrolysates Research Articles

Alcalase-Based Chickpea (Cicer arietinum L.) Protein Hydrolysates Efficiently Reduce Systolic Blood Pressure in Spontaneously Hypertensive Rats.

Studies on antihypertensive chickpea protein hydrolysates have rarely performed in vivo evaluations, limiting the entry of such hydrolysates into functional food development and clinical trials. Thus, our aim was to optimize the hydrolysis conditions to produce an alcalase-based chickpea hydrolysate with a hypotensive effect in vivo at convenient oral doses. The hydrolysis reaction time, temperature, and alcalase/substrate concentration were optimized using a response surface analysis (RSA). ACE-I inhibition was the response variable. The optimized hydrolysis conditions were time = 0.5 h, temperature = 40 °C, and E/S concentration = 0.254 (U/g). The IC50 of the optimized hydrolysate (OCPH) was 0.358 mg/mL. Five hydrolysates from the RSA worksheet (one of them obtained after 5 min of hydrolysis (CPH15)) had an ACE-I inhibitory potential similar to that of OCPH (p > 0.05). At 50 mg/kg doses, OCPH and CPH15 promoted a clinically relevant hypotensive effect in spontaneously hypertensive rats, up to -47.35 mmHg and -28.95 mmHg, respectively (p < 0.05 vs. negative control). Furthermore, the hypotensive effect was sustained for at least 7 h post-supplementation. Overall, OCPH and CPH15 are promising ingredients for functional food development and as test materials for clinical trials.

Metabolomic insights into the effect of chickpea protein hydrolysate on the freeze–thaw tolerance of industrial yeasts

The use of frozen dough is an intensive food-processing practice that contributes to the development of chain operations in the bakery industry. However, the fermentation activity of yeasts in frozen dough can be severely damaged by freeze–thaw stress, thereby degrading the final bread quality. In this study, chickpea protein hydrolysate significantly improved the quality of steamed bread made from frozen dough while enhancing the yeast survival rate and maintaining yeast cell structural integrity under freeze–thaw stress. The mechanism underlying this protective role of chickpea protein hydrolysate was further investigated by untargeted metabolomics analysis, which suggested that chickpea protein hydrolysate altered the intracellular metabolites associated with central carbon metabolism, amino acid synthesis, and lipid metabolism to improve yeast cell freeze–thaw tolerance. Therefore, chickpea protein hydrolysate is a promising natural antifreeze component for yeast cryopreservation in the frozen dough industry.

Production of chickpea protein hydrolysate at laboratory and pilot plant scales: Optimization using principal component analysis based on antioxidant activities

Chickpeas are a nutrient-rich source with optimal and high essential amino acid score. To evaluate its potential as a functional food ingredient, 36 chickpea protein hydrolysates were produced at the lab-scale using food-grade enzymes. Parameters including yields, protein content, hydrolysis degree, and antioxidant activities were employed to identify the most favourable conditions for scaling up production to a pilot plant level using a principal component analysis. The selected hydrolysate demonstrated commendable traits: a substantial content of essential amino acids and proteins at 67.71%, notable protein (73.12%) and weight (72.00%) yields, coupled with exceptional solubility exceeding 80%, and a noteworthy digestibility of 89.50%. Upon transition to pilot plant proportions, the hydrolysate retained its attenuated protein profile while exhibiting heightened antioxidant activities. Derived chickpea protein hydrolysates offer promise for innovative foods applications, impacting health and chronic disease prevention.

Antioxidant, anti-inflammatory, hypoglycemic, and anti-hyperglycemic activity of chickpea protein hydrolysates evaluated in BALB-c mice.

Chickpea (ICC3761) protein hydrolysates have shown high in vitro antioxidant activity (AoxA) and antidiabetic potential. The aim of this study was to evaluate the in vivo activities (i.e., antioxidant, anti-inflammatory, hypoglycemic, and anti-hyperglycemic) of chickpea albumin hydrolysates (CAH) obtained with alcalase and pepsin-pancreatin (fractions ≤ 10kDa). The CAH were analyzed for degree of hydrolysis (DH), electrophoretic and chromatographic profiles, and in vitro AoxA (2,2'-azino-bis(3-ethylbenzothiazolin)-6-sulfonic acid [ABTS], 2,2-diphenyl-1-pycrilhydrazyl [DPPH]). They were also evaluated for AoxA, anti-inflammatory and hypo- and anti-hyperglycemic activities in BALB-c mice. The DH was 20% for the alcalase CAH and 50% for the pepsin-pancreatin CAH, while the AoxA by ABTS (1mg/mL) was 64.8% and 64.9% and by DPPH (5mg/mL) was 48.0% and 31.1%. In the in vivo AoxA assay, mice of non-damaged control and those treated with both CAH showed similar alkaline phosphatase values, control and pepsin-pancreatin treated groups had similar malondialdehyde levels, while treated and non-damaged control groups had higher glutathione levels than the damaged control. Liver histopathology revealed that the pepsin-pancreatin CAH mitigated most of the pathological changes associated with the induced oxidative damage. Both CAH (2mg/ear) reduced croton oil-induced ear edema in mice. The α-glucosidase inhibition of CAH (100mg/mL) was 31.1% (alcalase) and 52.4% (pepsin-pancreatin). Mice treated with alcalase CAH (100mg/mL) and glibenclamide exhibited similar hypoglycemic activities, whereas only those treated with the pepsin-pancreatin CAH (200mg/kg body weight) showed anti-hyperglycemic activity. The results indicate that CAH can be used as a source of bioactive peptides with antioxidant, anti-inflammatory, hypoglycemic, and anti-hyperglycemic activities.

Trypsin-treated chickpea protein hydrolysate enhances the cytoaffinity of microbeads for cultured meat application

Cultured meat is believed to be a promising alternative to conventional meat production that can reduce environmental impacts, animal suffering, and food safety risks. However, one of the major challenges in producing cultured meat is to provide suitable microcarriers that can support cell attachment, proliferation, and differentiation. In this study, we developed novel microcarriers based on chickpea protein hydrolysates functionalized with trypsin. These microcarriers exhibited superior cytoaffinity and proliferation for various types of cultured cells, including C2C12, porcine myoblasts, chicken satellite cells, and 3T3-L1. Moreover, these microcarriers enabled cell differentiation into muscle or fat cells under appropriate conditions. We propose that trypsin treatment enhances the cytoaffinity of chickpea protein hydrolysates by exposing lysine and arginine residues that can interact with cell surface receptors. Our results suggest that chickpea protein hydrolysate functionalized microcarrier is a promising substrate for cultured meat production with cost-effectiveness and scalability.

Identification of Novel Dipeptidyl Peptidase-IV Inhibitory Peptides in Chickpea Protein Hydrolysates.

Dipeptidyl peptidase-IV (DPP-IV) is one of the main targets for blood sugar control. Some food protein-derived peptides are thought to have DPP-IV inhibitory (DPP-IVi) activity. In this study, chickpea protein hydrolysates (CPHs) obtained through Neutrase hydrolysis for 60 min (CPHs-Pro-60) exhibited the highest DPP-IVi activity. DPP-IVi activity after simulated in vitro gastrointestinal digestion was maintained at >60%. Peptide libraries are established after the identification of peptide sequences. Molecular docking verified that the four screened peptides (AAWPGHPEF, LAFP, IAIPPGIPYW, and PPGIPYW) could bind to the active center of DPP-IV. Notably, IAIPPGIPYW exhibited the most potent DPP-IVi activity (half maximal inhibitory concentration (IC50): 12.43 μM). Both IAIPPGIPYW and PPGIPYW exhibited excellent DPP-IVi activity in Caco-2 cells. These results indicated that chickpea could be used as a source of natural hypoglycemic peptides for food and nutritional applications.

Chickpea protein hydrolysate as a novel plant-based cryoprotectant in frozen surimi: Insights into protein structure integrity and gelling behaviors

Chickpea protein (CP) and its enzymatic hydrolysates are one of the most widely consumed pulse ingredients manifesting versatile applications in food industry, such as binders, emulsifiers, and meat protein substitutes. Other than those well-known functionalities, however, the use of CP as a cryoprotectant remained unexplored. In this study, we prepared the chickpea protein hydrolysate (CPH) and investigated its cryoprotective effects to frozen surimi in terms of the protein structure integrity and gelling behaviors. Results indicated that CPH could inhibit myofibrillar protein (MP) denaturation and oxidation during the freeze–thaw cycling, as evidenced by their increased solubility, Ca2+-ATPase activity, sulfhydryl concentration, and declined content of disulfide bonds, carbonyl concentration and surface hydrophobicity. Freezing-induced changes on MP secondary structures were also retarded. Moreover, gels prepared from CPH-protected frozen surimi demonstrated more stabilized microstructure, uniform water distribution, enhanced elasticity, gel strength and water holding capacity. The CPH alone, at a reducing addition content of 4% (w/w), exhibited comparable cryoprotective performance to that of the commercial formulation (4% sucrose and 4% sorbitol). Therefore, this study provides scientific insights for development of pulse proteins as novel and high-performance food cryoprotectants.

Identification of Novel Peptides with Alcohol Dehydrogenase (ADH) Activating Ability in Chickpea Protein Hydrolysates.

Alcohol dehydrogenase (ADH) is one of the main rate-limiting enzymes in alcohol metabolism. Food protein-derived peptides are thought to have ADH activating ability. We verified for the first time that chickpea protein hydrolysates (CPHs) had the ability to activate ADH and identified novel peptides from them. CPHs obtained by hydrolysis with Alcalase for 30 min (CPHs-Pro-30) showed the highest ADH activating ability, and the ADH activation rate could still maintain more than 80% after in vitro simulated gastrointestinal digestion. We have verified four peptides with activation ability to ADH: ILPHF, MFPHLPSF, LMLPHF and FDLPALRF (concentration for 50% of maximal effect (EC50): 1.56 ± 0.07 µM, 1.62 ± 0.23 µM, 1.76 ± 0.03 µM and 9.11 ± 0.11 µM, respectively). Molecular docking showed that the mechanism for activating ADH was due to the formation of a stable complex between the peptide and the active center of ADH through hydrogen bonding. The findings suggest that CPHs and peptides with ADH activating ability may be developed as natural anti-alcoholic ingredients to prevent alcoholic liver disease (ALD).

Effects of simulated gastrointestinal digestion on chickpea protein, and its hydrolysate physicochemical properties, erythrocyte haemolysis inhibition, and chemical antioxidant activity

Chickpea protein and its hydrolysates have good antioxidant activity. Proteins and peptides are degraded and modified in the gastrointestinal tract before being digested and absorbed, a process that changes their physicochemical and biological properties. Changes in structure and antioxidant capacity of the chickpea protein and its hydrolysates after simulated gastrointestinal digestion were studied. The secondary structure, amino acid composition, and chemical antioxidant activity of chickpea protein and its hydrolysates were determined, and their protective effects on AAPH-induced erythrocyte oxidative damage were studied. Results showed that chickpea protein hydrolysate was easier to be digested by the gastrointestinal tract than chickpea protein. After digestion, the chemical antioxidant capacity of chickpea protein and its hydrolysates increased in a dose-dependent manner, and showed a protective effect against erythrocytes AAPH-induced oxidative damage. Chickpea protein and its hydrolysates can be used as natural antioxidants to promote healthy digestion.

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.

Extrusion Improves the Antihypertensive Potential of a Kabuli Chickpea (Cicer arietinum L.) Protein Hydrolysate.

Chickpea hydrolysates could have antihypertensive potential, but there are no evaluations in vivo. Thus, the antihypertensive potential of a chickpea protein hydrolysate obtained before and after extrusion (a process that modifies protein digestibility) was evaluated. Protein precipitates were obtained from extruded and unextruded chickpea flours by isoelectric precipitation and hydrolyzed (α-amylase/pepsin/pancreatin). Chemical composition was determined (standard methods). ACE-I inhibition assays were carried out using a colorimetric test. For antihypertensive effect evaluations, spontaneously hypertensive rats (n = 8) received the treatments intragastrically (extruded or unextruded hydrolysate (1.2 g/kg), captopril (25 mg/kg), or water only). Fat, ash, and carbohydrate contents were lower in extruded chickpea flour (p < 0.05 versus unextruded). The protein content varied between protein precipitates (91.03%/78.66% unextruded/extruded (dry basis)) (p < 0.05). The hydrolysates’ IC50 values (mg/mL) were 0.2834 (unextruded)/0.3218 (extruded) (p > 0.05). All treatments lowered the blood pressure (p < 0.05 vs. water). The extruded hydrolysate showed a more potent antihypertensive effect than the unextruded one (p < 0.05), an effect similar to captopril (p > 0.05). The results suggest that protein extrusion can be used to generate protein hydrolysates with improved health benefits. The findings have implications for the design and production of functional foods that could help to prevent hypertension or serve as an adjunct in its treatment.

Chickpea Protein Hydrolysate Ameliorates the Impact of Feeding a High-Fat-Diet-Induced Obesity in Mice by Modulating Inflammation

ObjectivesTo evaluate the efficacy of a chickpea (Cicer arietinum) protein hydrolysate (CPH) on ameliorating markers of obesity in a mouse model of metabolic dysfunction when fed a high fat diet. MethodsCPH was produced using an Alcalase® and Flavourzyme® dual-system. Fifty-two male C57BL/6J mice (6 weeks of age) were randomized into four groups (n = 13/group) and fed daily, for a period of 16 weeks, as follows: standard diet (SD), high-fat diet (HFD), HFD + 400 mg CPH/kg body weight (BW) (400 CPH), and HFD + 800 mg CPH/kg BW (800 CPH). BW was measured weekly and blood glucose biweekly via tail bleeding. Feces were collected during week 16. Tissue samples were collected at the end of the study. Protein expression was measured in blood plasma, and metabolites relative concentrations in feces. Gene expression analyses were performed on liver, adipose, and pancreas tissues. ResultsWeight gain for the 800 CPH group was significantly lower (19%, P < 0.01) than the weight gain in the HFD group. Both, adipose and liver tissue weights were significantly lower (12% and 26%, P < 0.05, respectively) in 800 CPH than in HFD. Group 800 CPH had significantly reduced (P < 0.05) plasma protein levels of interleukin (IL)-1 α (14%), IL-4 (35%), IL-9 (32%), lymphotactin (37%), MCP-1 (48%), MIP-1 γ (40%), and TNF- α (40%) as compared to the HFD group. In liver, the 400 CPH group had upregulation (fold change [FC] >2) of genes related to lipid metabolism (Acsl4) and adipokine signaling (Adipor2) and downregulation (FC 0.3–0.5) of genes related to insulin signaling (Pik3r1, Ikbkb, Map2k1) when compared to HFD. In adipose tissue, the 800 CPH group modulated (FC > 2) genes related to inflammation (IL1B and IL18R1), and carbohydrate metabolism (Hk2) compared to the HFD group. The 400 CPH group had significant (FC > 2) upregulation of Tlr4 in pancreas tissue as compared to HFD. More than two hundred metabolites were identified in feces; branched-chain amino acids leucine and isoleucine decreased their relative concentrations in 800 CPH in comparison to HFD. ConclusionsFindings indicated that mice fed CPH had lower BW, reduced levels of inflammatory proteins in plasma, downregulated genes related to insulin signaling, and upregulated genes related to lipid metabolism, and adipokine signaling. Funding SourcesUSDA Pulses Division.

Effect of Germinated Chickpea Protein Hydrolysate on Markers of Type-2 Diabetes and Its Relationship to Bitter Taste Receptor Expression

ObjectivesTo evaluate the effect of an optimized germinated chickpea protein hydrolysate (GCPH) on markers of type-2 diabetes such as dipeptidyl peptidase-IV (DPP-IV) inhibition, glucose uptake and expression of glucose transporters in enterocytes and their relationship to bitter taste receptor expression. MethodsGCPH was characterized using LC-ESI-MS/MS. The bioactivity of the peptides and bitterness were characterized using the BioPep database. Predicted activation of bitter receptors was determined with BitterX. The energy of affinity was determined using molecular docking with DPP-IV, SGLT1, GLUT2, lipoprotein lipase (LPL) and fatty acid synthase (FAS). Glucose uptake was evaluated in Caco-2 cells and 3T3-L1 MBX adipocytes. The expression of glucose transporters SGLT1and GLUT2, and DPP-IV inhibition after GCPH treatment were also evaluated in Caco-2 cells. Lipid accumulation, triglycerol content, LPL and FAS activities were analyzed in 3T3-L1 MBX adipocytes. ResultsThree peptides, FDLPAL, GEAGR and VVFW were identified from legumin, all of which inhibited DPP-IV. Bitter fragments were found in several peptides and were predicted to activate bitter receptor hTAS2R14. FDLPAL was the most potent peptide inhibiting DPP-IV (–9.4 kcal/mol), SGLT1 (–9.3 kcal/mol) the enoyl-acyl carrier protein-reductase domain (–10.5 kcal/mol) and FAS β-ketoacyl reductase domain (–8.9 kcal/mol). VVFW was the most potent in inhibiting LPL (–6.6 kcal/mol) and GLUT2 (–11.2 kcal/mol). GEAGR was the most potent inhibitor of FAS thioesterase domain (–7.4 kcal/mol). GCPH inhibited DPP-IV (P < 0.05) in Caco-2 cells (IC50 2.1 mM) and glucose uptake at 1 mM (22%, P < 0.05) compared to untreated cells. GLUT2 expression was not different from a known inhibitor (phloretin, 100 μM, p > 0.05) at 2.5 mM. Bitter receptor TAS2R38 expression was suppressed with GCPH increasing concentrations up to 6.4-fold at 2.5 mM GCPH. ConclusionsGCPH inhibited glucose uptake in enterocytes and GLUT2, DPP-IV and TAS2R38 in a dose-dependent manner. GCPH showed potential to be used as a functional ingredient in industrially processed foods. Funding SourcesUSDA\\Pulse Crop Health Initiative.

Protective properties of sardine and chickpea protein hydrolysates against lipoprotein oxidative damages and some inflammation markers in hypercholesterolemic rats

OBJECTIVE: This study evaluated the effect of sardine (SPH) and chickpea protein hydrolysates (CPH) on oxidant stress and inflammatory profile in cholesterol-fed rats. METHODS: The experiment was undertaken for thirty days on 18 cholesterol-fed Wistar rats (220±10 g) divided into three groups and receiving 1 g/kg of body weight either chickpea protein hydrolysate (CPH), sardine protein hydrolysate (SPH) or casein in water (CG). RESULTS: Compared to CG, SPH and CPH treatment reduced cholesterol, hydroperoxide and malondialdehyde contents in serum, lipoproteins, erythrocytes and aorta. These same treated groups showed also lower serum isoprostane levels. However, serum paraoxonase activity and HDL-antioxidant property were improved only by CPH compared to CG. SOD activity of aorta and erythrocytes was higher in CPH but in SPH group, SOD activity was lower in these tissues and remained unchanged in serum. Furthermore, CPH and SPH stimulated glutathione peroxidase and catalase activities of aorta and erythrocytes. In CPH group, nitric oxide levels of serum, erythrocytes and aorta were increased by respectively 1.4- to 1.8-fold compared to CG and SPH. In addition, among the three groups, CPH exhibited the best anti-inflammatory effect by lowering serum C reactive protein, uric acid and albumin concentrations. CONCLUSIONS: SPH and particularly CPH possess antioxidant and anti-inflammatory properties and could be useful as nutraceuticals for health improving and preventing numerous disorders such as cardiovascular diseases.

Optimization, identification, and comparison of peptides from germinated chickpea (Cicer arietinum) protein hydrolysates using either papain or ficin and their relationship with markers of type 2 diabetes

The objective was to optimize and compare the production of antidiabetic peptides from germinated chickpea isolated protein using either papain or ficin. Kabuli chickpeas were germinated for 2, 4 and 6 days. Proteins were isolated, and peptides were produced based on a central composite design selecting human dipeptidyl peptidase (DPP-IV) inhibition as a response. Peptide sequencing was performed to identify and evaluate the physiochemical, biochemical and bitterness properties. DPP-IV inhibition using papain was 84.66 ± 8.72%, with ficin being 72.05 ± 1.20%. The optimum hydrolysate conditions were 6 days germination, 1:10 E/S, and 30 min ficin hydrolysis; SPGAGKG, GLAR, and STSA were identified. Pure SPGAGKG had relatively high affinity for DPP-IV (−7.2 kcal/mol) and α-glucosidase inhibition (−5.9 kcal/mol), with an IC50 of 0.27 mg/mL for DPP-IV inhibition. Peptides in the chickpea hydrolysate inhibited markers of T2D, indicating that the optimal conditions could be used to prepare a functional food ingredient.

Physicochemical properties and antioxidant activity of enzymatic hydrolysed chickpea (Cicer arietinum L.) protein as influence by alcalase and papain enzyme

Alcalase is a protease which prepared from the Bacillus licheniformis bacteria, whereas papain is a cysteine protease which prepared from plant sources papaya fruit latex, and both are utilized in enzymatic hydrolysis. However, each enzyme showed different effect during the hydrolysis process. In this present research, the effects of two commercial proteases, alcalase and papain, on the preparation and characterisation of physiochemical properties and antioxidant activity of chickpea (Cicer arietinum L.) protein hydrolysate (CPH) were studied. Different parameters were used during hydrolysis using alcalase (pH 10, temperature 45 °C) and papain (pH 6.7, temperature 65 °C). CPH hydrolysed by enzyme alcalase (CPHA) showed higher yields (32.5%) and degree of hydrolysis (DH) (8.62%) than CPH hydrolysed by enzyme papain (CPHP), which had lower yields (13.92%) and DH (7.99%). In addition, CPHA led to a lower molecular weight (10 kDa) than CPHP (14.3 kDa). However, in terms of chemical composition and solubility, no significant differences existed between CPHA and CPHP. Moreover, CPHA showed significantly higher foaming capacity, foaming stability, emulsifying stability, antioxidant activity on DPPH radical scavenging activity as compared to CPHP. CPHA also showed significantly lower emulsifying capacity than CPHP. These findings indicate that the type of protease used to hydrolyse CPH has a significant impact on the physicochemical properties and antioxidant activity of the produced CPH. • The yield of CPHA was higher (32.5%) than CPHP (13.92%). • CPHA showed a higher DH value however lower in molecular weight value than CPHP. • CPHA had a better foaming capacity, stability, and emulsifying stability than CPHP. • CPHA showed a lower emulsifying capacity (52.94%) than CPHP (57.33%). • CPHA had higher antioxidant activity in DPPH radical scavenging activity (79.57%).

Identification and Comparison of Peptides from Chickpea Protein Hydrolysates Using Either Bromelain or Gastrointestinal Enzymes and Their Relationship with Markers of Type 2 Diabetes and Bitterness.

The chickpea (Cicer arietinum L.) is one of the most important pulses worldwide. The objective was to identify, compare and evaluate peptides from chickpea hydrolysates produced by two enzymatic treatments. The antidiabetic potential and bitterness of the peptides and induction of bitter receptors were identified in silico. Proteins were isolated from the Kabuli variety. Peptides were produced from the proteins using a simulated digestive system (pepsin/pancreatin, 1:50 Enzyme/Protein, E/P), and these peptides were compared with those produced via bromelain hydrolysis (1:50 E/P). The protein profiles, sequences and characteristics of the peptides were evaluated. The biochemical inhibition and molecular docking of dipeptidyl peptidase-IV (DPP-IV), α-amylase and α-glucosidase were also studied. The molecular docking identified peptides from enzymatic hydrolysis as inhibitors of DPP-IV. The high hydrophobicity of the peptides indicated the potential for bitterness. There was no correlation between peptide length and DPP-IV binding. Peptides sequenced from the pepsin/pancreatin hydrolysates, PHPATSGGGL and YVDGSGTPLT, had greater affinity for the DPP-IV catalytic site than the peptides from the bromelain hydrolysates. These results are in agreement with their biochemical inhibition, when considering the inhibition of sitagliptin (54.3 µg/mL) as a standard. The bitter receptors hTAS2R38, hTAS2R5, hTAS2R7 and hTAS2R14 were stimulated by most sequences, which could be beneficial in the treatment of type 2 diabetes. Chickpea hydrolysates could be utilized as functional ingredients to be included in the diet for the prevention of diabetes.

Enzymatic Production, Bioactivity, and Bitterness of Chickpea (Cicer arietinum) Peptides.

Chickpeas are inexpensive, protein rich (approximately 20% dry mass) pulses available worldwide whose consumption has been correlated with positive health outcomes. Dietary peptides are important molecules derived from dietary proteins, but a comprehensive analysis of the peptides that can be produced from chickpea proteins is missing in the literature. This review provides information from the past 20 years on the enzymatic production of peptides from chickpea proteins, the reported bioactivities of chickpea protein hydrolysates and peptides, and the potential bitterness of chickpea peptides in food products. Chickpea peptides have been enzymatically produced with pepsin, trypsin, chymotrypsin, alcalase, flavorzyme, and papain either alone or in combination, but the sequences of many of the peptides in chickpea protein hydrolysates remain unknown. In addition, a theoretical hydrolysis of chickpea legumin by stem bromelain and ficin was performed by the authors to highlight the potential use of these enzymes to produce bioactive chickpea peptides. Antioxidant activity, hypocholesterolemic, and angiotensin 1-converting enzyme inhibition are the most studied bioactivities of chickpea protein hydrolysates and peptides, but anticarcinogenic, antimicrobial, and anti-inflammatory effects have also been reported for chickpea protein hydrolysates and peptides. Chickpea bioactive peptides are not currently commercialized, but their bitterness could be a major impediment to their incorporation in food products. Use of flavorzyme in the production of chickpea protein hydrolysates has been proposed to decrease their bitterness. Future research should focus on the optimization of chickpea bioactive peptide enzymatic production, studying the bioactivity of chickpea peptides in humans, and systematically analyzing chickpea peptide bitterness.

Effect of enzymatic hydrolysis using endo- and exo-proteases on secondary structure, functional, and antioxidant properties of chickpea protein hydrolysates

Chickpea protein isolate was hydrolyzed batchwise using Alcalase as an endopeptidase and Flavourzyme as an exopeptidase, by either individual or sequential treatment. Secondary structure, SDS-PAGE molecular weight profile, functional properties, and antioxidant activity of the hydrolysates were investigated. Alcalase was more effective than Flavourzyme to cleave the peptide bonds, and the degree of hydrolysis (DH) of Alcalase-treated hydrolysate was 25.8% compared to Flavourzyme-treated counterpart with a DH of 11.9%. Sequential treatment increased the DH up to 50%. The hydrolysis process significantly changed the protein’s secondary structure characterized by decreased ordered structures and increased disordered structures. The more notable changes occurred for those that were treated sequentially. Protein banding patterns of the hydrolysates were also markedly changed, especially for those treated by Alcalase in which no visible band was observed. Furthermore, hydrolysates had a significant (P < 0.05) increase in the solubility, emulsifying capacity, and DPPH· scavenging capacity. The changes in DH and protein secondary structure significantly correlated with functional properties and DPPH· scavenging capacity. DH presented a significant inverse association with emulsifying stability (r = − 0.940), but a positive correlation with DPPH· scavenging activity (r = 0.951). β-sheet was found to be negatively correlated with both solubility (r = − 0.979) and DPPH· scavenging activity (r = − 0.979). However, an opposite trend was observed for β-turn which positively correlated with both solubility (r = 0.881) and DPPH· scavenging activity (r = − 0.909). The results reveal that hydrolysis enhanced the functional properties and antioxidant activity of chickpea protein which may be beneficial for potential functional food ingredient applications.

Impact of hydrolysis on functional properties, antioxidant, ACE-I inhibitory and antiproliferative activity of Cicer arietinum and Cicer reticulatum hydrolysates

Chickpea is an important food legume of the world offering valuable nutrients. Employing the degree of hydrolysis (DH) by the enzyme alcalase and flavourzyme, the functional properties of two chickpea species i.e. Cicer arietinum and Cicer reticulatum was investigated. This includes antioxidant, physicochemical properties and angiotensin-converting enzyme (ACE-I) inhibitory activities. Hydrolysis reaction was performed in different time intervals including 0, 20, 40, 60, 80, and 100 min by adding 2% (w/v) alcalase (pH 8) and flavourzyme (pH 7) at 50 °C temperature and pH was kept constant during hydrolysis time. DH improved through solubility of chickpea isolate in the pH range of 5–10. Alcalase produced a maximum degree of hydrolysis at 60 min for both the Cicer species. Flavourzyme demonstrated the highest degree hydrolysis for C. arietinum at 80 min and C. reticulatum at 100 min. The Cicer protein hydrolysates showed the highest antioxidant, ACE-I inhibitory and antiproliferative activity. As a prerequisite to food industry, present study revealed that chickpea protein hydrolysate (CPH) can be appraised as a source of functional food.