ABSTRACT
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.
Subject(s)
Angiotensin-Converting Enzyme Inhibitors , Arachis , Peptidyl-Dipeptidase A , Plant Proteins , Protein Hydrolysates , Renin , Subtilisins , Subtilisins/metabolism , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Angiotensin-Converting Enzyme Inhibitors/chemistry , Angiotensin-Converting Enzyme Inhibitors/metabolism , Protein Hydrolysates/pharmacology , Protein Hydrolysates/chemistry , Protein Hydrolysates/metabolism , Arachis/chemistry , Renin/metabolism , Renin/antagonists & inhibitors , Hydrolysis , Plant Proteins/metabolism , Plant Proteins/pharmacology , Plant Proteins/chemistry , Peptidyl-Dipeptidase A/metabolism , Peptidyl-Dipeptidase A/chemistry , Antihypertensive Agents/pharmacology , Antihypertensive Agents/chemistry , HumansABSTRACT
The Jatropha curcas cake, a protein-rich by-product of biofuel production, was the subject of our study. We identified and quantified the ACE inhibitory, antioxidant, and antidiabetic activities of bioactive peptides from a Jatropha curcas L. var Sevangel protein isolate. The protein isolate (20.44% recovered dry matter, 38.75% protein content, and 34.98% protein yield) was subjected to two enzyme systems for hydrolysis: alcalase (PEJA) and flavourzyme (PEJF), recording every 2 h until 8 h had passed. The highest proteolytic capacity in PEJA was reached at 2 h (4041.38 ± 50.89), while in PEJF, it was reached at 6 h (3435.16 ± 59.31). Gel electrophoresis of the PEJA and PEJF samples showed bands corresponding to peptides smaller than 10 kDa in both systems studied. The highest values for the antioxidant capacity (DPPH) were obtained at 4 h for PEJA (56.17 ± 1.14), while they were obtained at 6 h for PEJF (26.64 ± 0.52). The highest values for the antihypertensive capacity were recorded at 6 h (86.46 ± 1.85) in PEJF. The highest antidiabetic capacity obtained for PEJA and PEJF was observed at 6 h, 68.86 ± 8.27 and 52.75 ± 2.23, respectively. This is the first report of their antidiabetic activity. Notably, alcalase hydrolysate outperformed flavourzyme hydrolysate and the cereals reported in other studies, confirming its better multi-bioactivity.
Subject(s)
Angiotensin-Converting Enzyme Inhibitors , Antioxidants , Hypoglycemic Agents , Jatropha , Plant Proteins , Jatropha/chemistry , Hydrolysis , Antioxidants/chemistry , Antioxidants/pharmacology , Angiotensin-Converting Enzyme Inhibitors/chemistry , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Plant Proteins/chemistry , Plant Proteins/isolation & purification , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Subtilisins/metabolism , Subtilisins/chemistry , EndopeptidasesABSTRACT
This study characterized the sleep activity, sleep mechanism, and active peptides of whey protein hydrolysates selected through behavioral analysis of fruit-flies (Drosophila melanogaster). Sleep-inducing whey protein (WP) hydrolysate was selected through fruit fly behavior analysis, and sleep activity was measured using a pentobarbital model and electroencephalographic analysis. The mechanism of action was confirmed using a γ-aminobutyric acid (GABA) receptor antagonist, and the active peptide was identified using liquid chromatography-mass spectroscopy. Whey protein hydrolysate, prepared using Alcalase and Prozyme (WP-AP), increased sleep time in a dose-dependent manner. WP-AP significantly increased not only sleep time but also slow-wave sleep and showed an insomnia-alleviating effect in a caffeine-induced insomnia mouse model. In addition, the gene and protein expression levels of GABA sub-type A (GABAA) receptors increased in the brains of mice orally administered with WP-AP. Through peptide analysis, the mixture of DIQK, VPPF peptide, and GABA contained in WP-AP was estimated to exhibit sleep activity, and due to its high content, DIQK was speculated to be the main sleep -inducing ingredient. These results indicate that WP-AP has the potential to be used as a new ingredient to improve sleep quality.
ABSTRACT
This study aimed to extract bioactive proteins and protein hydrolysates from Apis mellifera larvae and assess their potential application in cosmetics as well as their irritation properties. The larvae were defatted and extracted using various mediums, including DI water, along with 0.5 M aqueous solutions of sodium hydroxide, ascorbic acid, citric acid, and hydrochloric acid. Subsequently, the crude proteins were hydrolyzed using the Alcalase® enzyme. All extracts underwent testing for antioxidant activities via the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and Griess assays. Anti-aging properties were evaluated in terms of anti-collagenase and anti-hyaluronidase effects. Irritation potential was assessed using the hen's egg chorioallantoic membrane (HET-CAM) test. The results revealed that the sodium hydroxide extraction showed promising outcomes in terms of yield, protein content, and effectiveness in inhibiting hyaluronidase, with the highest inhibition at 78.1 ± 1.5%, comparable to that of oleanolic acid. Conversely, crude protein extracted with ascorbic acid and its hydrolysate showed notable antioxidant and collagenase-inhibitory activities. Remarkably, their anti-collagenase effects were comparable to those of ascorbic acid and lysine. Additionally, it demonstrated safety upon testing with the CAM. In conclusion, the findings provided valuable insights into the utilization of A. mellifera larval proteins as active ingredients with a wide range of cosmeceutical applications, particularly due to their antioxidant, anti-aging, and low irritation properties, which hold significant promise for anti-skin wrinkles.
ABSTRACT
The study aimed to optimize ultrasonic (US: 40 kHz/200 W for 10, 20, 30, 40, and 50 min), and microwave (MW: 160 W for 45, 90, 125, 180, and 225 s) pretreatment conditions on protein extraction yield and degree of protein hydrolysis (DH) from almond de-oiled meal, an industrial by-product. First order model was used to describe the kinetics of almond protein hydrolysates obtained with Alcalase. The highest DH, 10.95% was recorded for the US-50 min and 8.87% for MW-45 s; while it was 5.76% for the untreated/control sample. At these optimized pretreatment conditions, a 1.16- and 1.18-fold increment in protein recovery was observed for the US and MW pretreatments, respectively in comparison to the conventional alkaline extraction. The molecular weight distribution recorded for pretreated samples disclosed a significant reduction in the band thickness in comparison with control. Both the pretreatments resulted in a significant increase (P < 0.05) in the antioxidant activity, and TCA solubility index when compared with the control. Results evinced that US and/or MW pretreatments before enzymatic hydrolysis can be a promising approach for the valorization of almond meal for its subsequent use as an ingredient for functional foods/nutraceuticals which otherwise fetches low value as an animal feed.
ABSTRACT
Effective reduction of the allergenicity of instant soy milk powder (ISMP) is practically valuable for expanding its applications. This study optimized the enzymolysis technology of ISMP using single-factor experiments and response surface methodology, combined serological analysis, cellular immunological models, bioinformatics tools, and multiple spectroscopy techniques to investigate the effects of alcalase hydrolysis on allergenicity, spatial conformation, and linear epitopes of ISMP. Under the optimal process, special IgE and IgG1 binding abilities and allergenic activity to induce cell degranulation of alcalase-hydrolyzed ISMP were reduced by (64.72 ± 1.76)%, (56.79 ± 3.72)%, and (73.3 ± 1.19)%, respectively (P < 0.05). Moreover, the spatial conformation of instant soy milk powder hydrolysates (ISMPH) changed, including decreased surface hydrophobicity, a weaker peak of amide II band, lower contents of α-helix and ß-sheet, and an enhanced content of random coil. Furthermore, the linear epitopes of major soy allergens, 9 from glycinin and 13 from ß-conglycinin, could be directionally disrupted by alcalase hydrolysis. Overall, the structure-activity mechanism of alcalase hydrolysis to reduce ISMP allergenicity in vitro was preliminarily clarified. It provided a new research direction for the breakthrough in the desensitization of ISMP and a theoretical basis for revealing the potential mechanism of alcalase enzymolysis to reduce the allergenicity of ISMP.
Subject(s)
Allergens , Soy Milk , Subtilisins , Humans , Allergens/chemistry , Allergens/immunology , Allergens/metabolism , Food Hypersensitivity/prevention & control , Food Hypersensitivity/immunology , Globulins/chemistry , Globulins/immunology , Hydrolysis , Immunoglobulin E/immunology , Immunoglobulin G/immunology , Powders/chemistry , Soy Milk/chemistry , Soybean Proteins/chemistry , Soybean Proteins/immunology , Soybean Proteins/metabolism , Structure-Activity Relationship , Subtilisins/metabolismABSTRACT
The impact of different pressure levels in the HHP-assisted hydrolysis by Alcalase of quinoa proteins on the catalytic efficiency, peptide release, phenolic compounds content, and biological activities was investigated. The protein profile (SDS-PAGE) showed a more extensive peptide breakdown for the HHP-assisted proteolysis at 300-400 MPa, which was confirmed by the higher extent of hydrolysis and peptide concentration. Quinoa protein hydrolysates (QPH) produced at 200 and 300 MPa exhibited higher total phenolic contents and antioxidant activities (methanol-acetone and aqueous extracts) when compared to the non-hydrolyzed (QPI) and non-pressurized hydrolyzed samples. Kaempferol dirhamnosyl-galactopyranoside was the prevalent phenolic compound in those samples, increasing total flavonoids by 1.8-fold over QPI. The QPH produced at 300 MPa inhibited ACE more effectively, exhibiting the greatest anti-hypertensive potential, along with the presence of several ACE-inhibitory peptides. The peptide sequences GSHWPFGGK, FSIAWPR, and PWLNFK presented the highest Peptide Ranker scores and were predicted to have ACE inhibitory, DPP-IV inhibitory, and antioxidant activities. Mild pressure levels were effective in producing QPH with enhanced functionality due to the effects of bioactive soluble phenolics and low molecular weight peptides.
Subject(s)
Antioxidants , Chenopodium quinoa , Hydrolysis , Antioxidants/pharmacology , Antioxidants/chemistry , Protein Hydrolysates/chemistry , Angiotensin-Converting Enzyme Inhibitors/chemistry , Peptides/chemistryABSTRACT
In this study, watermelon seeds (Citrullus lanatus) protein hydrolyzed (WSPH) was produced using microbial enzymes Alcalase and Protamex. Then, the effect of different concentrations of WSPH (0, 1, 2, and 3%) on the quality of the silver carp (Hypophthalmichthys molitrix) burger during refrigerated storage (4 ± 1 °C) was investigated. According to the results, WSPH by alcalase had significantly higher degree of hydrolysis and antioxidant activity (p < 0.05) and it was used for burger tests. The results showed that, the addition of WSPH was able to reduce the microbial, chemical spoilage and sensory score during 16 days compared to the control, and with increasing the concentration of WSPH, better results were observed (p < 0.05). According to the chemical, microbial and sensory indicators, WSPH at 3% could increase the shelf life of fish burgers up to 8 days compared to the control, and this treatment was within the permissible quality limit until the end of the refrigerated storage.
ABSTRACT
Muscle atrophy is a complex physiological condition caused by a variety of reasons, including muscle disuse, aging, malnutrition, chronic diseases, immobilization, and hormonal imbalance. Beyond its effect on physical appearance, this condition significantly reduces the quality of human life, thus warranting the development of preventive strategies. Although exercising is effective in managing this condition, it is applicable only for individuals who can engage in physical activities and are not bedridden. A combination of exercise and nutritional supplementation has emerged as a more advantageous approach. Here, we evaluated the effects of enzyme-assisted hydrolysates of Mytilus edulis prepared using Protamex (PMH), Alcalase (AMH), or Flavourzyme (FMH) in protecting against muscle atrophy in a dexamethasone (Dex)-induced muscular atrophy model in vitro and in vitro. Alcalase-assisted M. edulis hydrolysate (AMH) was the most efficient among the tested treatments and resulted in higher protein recovery (57.06 ± 0.42%) and abundant amino acid composition (43,158 mg/100 g; 43.16%). AMH treatment also escalated the proliferation of C2C12 cells while increasing the total number of nuclei, myotube coverage, and myotube diameter. These results were corroborated by a successful reduction in the levels of proteins responsible for muscle atrophy, including E3 ubiquitin ligases, and an increase in the expression of proteins associated with muscle hypertrophy, including myogenin and MyHC. These results were further solidified by the successful enhancement of locomotor ability and body weight in zebrafish following AMH treatment. Thus, these findings highlight the potential of AMH in recovery from muscle atrophy.
Subject(s)
Mytilus edulis , Animals , Humans , Subtilisins , Zebrafish , Muscular Atrophy/drug therapy , Muscular Atrophy/prevention & control , Muscular Atrophy/chemically induced , Muscle Fibers, Skeletal , Muscle, SkeletalABSTRACT
Because of the health benefits and economic opportunities, extracting bioactive peptides from plant proteins, often food processing by-products, garners significant interest. However, the high enzyme costs and the emergence of bitter peptides have posed significant challenges in production. This study achieved the immobilization of Alcalase and Flavorzyme using cost-effective SiO2 microparticles. Mussel-inspired chemistry and biocompatible polymers were employed, with genipin replacing glutaraldehyde for safer crosslinking. This approach yielded an enzyme loading capacity of approximately 25 mg/g support, with specific activity levels reaching around 180 U/mg for immobilized Alcalase (IA) and 35 U/mg for immobilized Flavorzyme (IF). These immobilized proteases exhibited improved activity and stability across a broader pH and temperature range. During the hydrolysis of soy proteins, the use of immobilized proteases avoided the thermal inactivation step, resulting in fewer peptide aggregates. Moreover, this study applied peptidomics and bioinformatics to profile peptides in each hydrolysate and identify bioactive ones. Cascade hydrolysis with IA and IF reduced the presence of bitter peptides by approximately 20%. Additionally, 50% of the identified peptides were predicted to have bioactive properties after in silico digestion simulation. This work offers a cost-effective way of generating bioactive peptides from soy proteins with reducing potential bitterness.
ABSTRACT
The study evaluated the efficacy of locust protein hydrolysates (LoPHs) to enhance the quality of Cheddar cheese (ChCh) during storage. The locust protein (LoP) was pre-treated [microwave (Mic) or ultrasonication (Ult) or no treatment (Not)] before hydrolysis using alcalase enzyme (3% w/w). The ChCh samples containing LoPHs at the maximum level of 1.5% were evaluated for quality for 3 months (4 ± 1 °C) and subjected to gastrointestinal simulation. Both pre-treatments (Mic and Ult) significantly (P < 0.05) enhanced the antimicrobial and antioxidant activities of the LoPHs (Ult > Mic > Not). The ChCh samples with LoPHs exhibited significantly (P < 0.05) lower means for lipid oxidation (TBARS and free fatty acids), protein oxidation (total-carbonyl content) and microbial counts (psychrophilic, total plate and yeast/moulds) during the storage. A positive effect was found on the sensory quality of ChCh samples after one month of storage. The gastrointestinal simulation improved the antioxidant capacity of the stored ChCh samples. LoPHs can be used as a novel bio-preservative for cheese.
ABSTRACT
The food enzyme subtilisin (serine endopeptidase, EC 3.4.21.62) is produced with the non-genetically modified Bacillus paralicheniformis strain DP-Dzx96 by Genencor International B.V. The food enzyme was considered free from viable cells of the production organism. The food enzyme is intended to be used in five food manufacturing processes: production of protein hydrolysates from plants and fungi, production of protein hydrolysates from meat and fish proteins, production of cooked rice, production of modified meat and fish products, and yeast processing. The production strain of the food enzyme contains known antimicrobial resistance genes. Bacitracin, a medically important antimicrobial, was detected in the food enzyme. The presence of bacitracin represents a risk for the development of antimicrobial resistant bacteria. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and three matches with respiratory and two matches with food allergens were found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to muskmelon or pomegranate, cannot be excluded, but would not exceed the risk of consuming these foods. Due to the presence of bacitracin, the Panel concluded that the food enzyme subtilisin produced with the non-genetically modified Bacillus paralicheniformis strain DP-Dzx96 cannot be considered safe.
ABSTRACT
Locust protein hydrolysates (LoProHs) pre-processed with microwave and ultrasonication were developed and evaluated for their potential for enhancing the quality of the stored meat emulsion (MEmul). Locust protein (LoPro) samples pre-processed with ultrasonication (Ult) or microwave (Mic) or with no treatment (Not) were hydrolysed with alcalase enzyme (3%). The microwave pre-processed (Mic-LoProHs) and ultrasonicated (Ult-LoProHs) hydrolysates showed significantly (P < 0.05) higher antioxidant [FRAP (ferric reducing antioxidant power) and ABTS and DPPH radical scavenging activities] and antimicrobial [minimum inhibitory concentration (MIC) and inhibitory halos (mm)] potential. The MEmul samples incorporated with Mic-LoProHs and Ult-LoProHs at the maximum level of 1.5% exhibited significantly (P < 0.05) improved results for all the quality parameters such as antioxidant potential (FRAP, ABTS and DPPH), protein oxidation (total carbonyl content), lipid stability, and microbial quality during refrigerated storage (4 ± 1 °C) of two-weeks compared to the control MEmul without any LoProHs. A positive (P < 0.05) impact of the LoProHs was found on the sensory quality of MEmul samples after one week of storage. The digestion simulation improved (P < 0.05) the antioxidant potential of the MEmul samples.
Subject(s)
Antioxidants , Protein Hydrolysates , Antioxidants/pharmacology , Antioxidants/chemistry , Protein Hydrolysates/chemistry , Emulsions/chemistry , Microwaves , MeatABSTRACT
Enzymatic protein hydrolysis is a well-established method for improving the quality of dietary proteins, including edible insects. Finding effective enzymes from natural sources is becoming increasingly important. This study used nuruk extract concentrate (NEC), an enzyme-rich fermentation starter, to produce protein hydrolysate from defatted Tenebrio molitor (also called mealworm, MW). The nutritional, functional, and sensorial properties of the hydrolysate were then compared to those obtained using commercial proteases (alcalase and flavourzyme). The protease activities of the crude nuruk extract (CNE), NEC, alcalase, and flavourzyme were 6.78, 12.71, 11.07, and 12.45 units/mL, respectively. The degree of hydrolysis and yield of MW hydrolysis by NEC were 15.10 and 35.92% (w/w), respectively. MW hydrolysate was obtained using NEC and had a significantly higher free amino acid content (90.37 mg/g) than alcalase (53.01 mg/g) and flavourzyme (79.64 mg/g) hydrolysates. Furthermore, the NEC hydrolysis of MW increased the antioxidant and angiotensin-converting enzyme inhibitory activity, with IC50 values of 3.07 and 0.15 mg/mL, respectively. The enzymatic hydrolysis also improved sensory properties, including umaminess, sweetness, and saltiness. Overall, this study found that the NEC hydrolysis of MW outperformed commercial proteases regarding nutritional quality, sensory attributes, and biological activity. Therefore, nuruk could potentially replace commercial proteases, lowering the cost of enzymatic protein hydrolysis.
ABSTRACT
Periodontitis is a chronic inflammatory disease induced by a plaque biofilm, which can lead to the destruction of the periodontal support tissue and even teeth loss. The common strategies of periodontitis treatment are to eliminate bacterial/biofilm-related inflammation and subsequently inhibit alveolar bone resorption, for which antibiotic therapy is the most traditional one. However, impenetrable polymeric substances on bacterial biofilms make it difficult for traditional antimicrobial agents to take effect. In this study, a novel nanoparticle protease-loaded CuS NPs was developed, combining the advances of photodynamic and photothermal therapy from CuS and enzymatic degradation of the biofilm by a protease. The photothermal activity and the reactive oxygen generation capacity of the designed nanoparticles were verified by the experimental results, constituting the basis of antibacterial function. Next, the high antimicrobial activity of CuS@A NPs onFusobacterium nucleatumand its biofilm was demonstrated. The proper hemo/cytocompatibility of CuS-based NPs was demonstrated by in vitro assays. Last, effective treatment against periodontitis was achieved in a rat periodontitis model through the significant efficacy of inhibiting bone resorption and alleviating inflammation. Thus, the developed CuS@A NPs prove a promising material for the management of periodontitis.
Subject(s)
Nanoparticles , Periodontitis , Photochemotherapy , Rats , Animals , Photochemotherapy/methods , Photothermal Therapy , Peptide Hydrolases , Periodontitis/drug therapy , Periodontitis/microbiology , Inflammation , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Copper/pharmacology , Copper/therapeutic useABSTRACT
The food enzyme subtilisin (serine endopeptidase, EC 3.4.21.62) is produced with the non-genetically modified microorganism Bacillus paralicheniformis strain LMG S-30155 by ENMEX SA de CV, now part of Kerry Food Ingredients (Cork) Ltd. The food enzyme is intended to be used in oil production, hydrolysis of vegetable/microbial/animal proteins, yeast processing and production of flavouring preparations. The production strain of the food enzyme contains known antimicrobial resistance genes and genes involved in bacitracin biosynthesis. Consequently, it does not fulfil the requirements for the QPS approach to safety assessment. Bacitracin was detected in the food enzyme and the â â â â â The presence of bacitracin, a medically important antimicrobial, in the food enzyme represents a risk for the development of resistance in bacteria. Due to the presence of bacitracin, the Panel concluded that the food enzyme subtilisin produced with the non-genetically modified Bacillus paralicheniformis strain LMG S-30155 cannot be considered safe.
ABSTRACT
Chitin is mostly produced from crustaceans, but it is difficult to supply raw materials due to marine pollution, and the commonly used chemical chitin extraction method is not environmentally friendly. Therefore, this study aims to establish a chitin extraction process using enzymes and to develop edible insect-derived chitin as an eco-friendly new material. The response surface methodology (RSM) was used to determine the optimal conditions for enzymatic hydrolysis. The optimal conditions for enzymatic hydrolysis by RSM were determined to be the substrate concentration (7.5%), enzyme concentration (80 µL/g), and reaction time (24 h). The solubility and DDA of the mealworm chitosan were 45% and 37%, respectively, and those of the commercial chitosan were 61% and 57%, respectively. In regard to the thermodynamic properties, the exothermic peak of mealworm chitin was similar to that of commercial chitin. In the FT-IR spectrum, a band was observed in mealworm chitin corresponding to the C=O of the NHCOCH3 group at 1645 cm-1, but this band showed low-intensity C=O in the mealworm chitosan due to deacetylation. Collectively, mealworm chitosan shows almost similar physical and chemical properties to commercial chitosan. Therefore, it is shown that an eco-friendly process can be introduced into chitosan production by using enzyme-extracted mealworms for chitin/chitosan production.
Subject(s)
Chitin , Chitosan , Subtilisins , Tenebrio , Animals , Acetylation , Calorimetry, Differential Scanning , Chitin/chemistry , Chitin/isolation & purification , Chitin/metabolism , Chitosan/chemistry , Chitosan/isolation & purification , Chitosan/metabolism , Crustacea/chemistry , Edible Insects/chemistry , Edible Insects/metabolism , Hydrolysis , Proteolysis , Solubility , Spectroscopy, Fourier Transform Infrared , Subtilisins/metabolism , Tenebrio/chemistry , Tenebrio/metabolism , ThermodynamicsABSTRACT
The aims of this study were to optimize the preparation of low-molecular-weight collagen using a proteolytic enzyme (alcalase) derived from the feet of Korean native chickens, and to characterize the process of collagen hydrolysis. Foreign bodies from chicken feet were removed using ultrasonication at 28 kHz with 1.36 kW for more than 25 min. The hydrolytic pattern and molecular weight distribution of enzyme-treated collagen from chicken feet were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography, respectively. Ideally, chicken feet should be treated at 100°C for 8 h to obtain a high collagen content using hot water extraction. The collagen content of the chicken foot extract was 13.9 g/100 g, and the proportion of low-molecular-weight collagen increased with increasing proteolytic enzyme concentration and reaction time. When treated with 1% alcalase, the average molecular weight of collagen decreased rapidly to 4,929 Da within 5 h and thereafter decreased at a slower rate, reaching 4,916 Da after 7 h. Size exclusion chromatography revealed that low-molecular-weight collagen peptides of approximately 1,000-5,000 Da were obtained after hydrolysis with 1% alcalase for 1 h.
Subject(s)
Chickens , Subtilisins , Animals , Molecular Weight , Subtilisins/chemistry , Collagen , Peptide Hydrolases , Republic of KoreaABSTRACT
Application of non-thermal treatment to proteins prior to enzymatic hydrolysis can facilitate the release of novel bioactive peptides (BPs) with unique biological activities. In this study, lupin protein isolate was pre-treated with ultrasound and hydrolysed using alcalase and flavourzyme to produce alcalase hydrolysate (ACT) and flavourzyme hydrolysate(FCT). These hydrolysates were fractionated into 1, 5, and 10 kDa molecular weight fractions using a membrane ultrafiltration technique. The in vitro angiotensin-converting enzyme (ACE) studies revealed that unfractionated ACT (IC50 = 3.21 mg mL-1) and FCT (IC50 = 3.32 mg mL-1) were more active inhibitors of ACE in comparison to their ultrafiltrated fractions with IC50 values ranging from 6.09 to 7.45 mg mL-1. Molecular docking analysis predicted three unique peptides from ACT (AIPPGIPY, SVPGCT, and QGAGG) and FCT (AIPINNPGKL, SGNQGP, and PPGIP) as potential ACE inhibitors. Thus, unique BPs with ACE inhibitory effects might be generated from ultrasonicated lupin protein.
Subject(s)
Antihypertensive Agents , Protein Hydrolysates , Antihypertensive Agents/chemistry , Molecular Docking Simulation , Protein Hydrolysates/chemistry , Peptides/chemistry , Peptidyl-Dipeptidase A/chemistry , Hydrolysis , Subtilisins/metabolismABSTRACT
This paper investigates the effect on the physicochemical and functional properties of soybean protein concentrate (SPC) by using Alcalase protease and high-pressure homogenization (HPH) (0, 20, 40, 60, 80, and 100 MPa) for the combined modification. The results showed that the degree of hydrolysis of SPC was 4.1% and the antigen protein was degraded after Alcalase hydrolysis, when the homogenization pressure (HP) was 6 0Mpa, the particle size of the SPC was the smallest, the zate potential absolute value up to 33.45 mV, the secondary structure has the lowest ß-sheet content, the highest random coil content, and the highest surface hydrophobicity (H0), the size of protein fragments on the microstructure surface is the smallest, the lowest denaturation temperature (T d ) and enthalpy (â³H) are 72.59°C and 1.35 J/g, the highest solubility is 80.54%, and the highest water and oil holding capacities are 7.73 g/g and 6.51 g/g, respectively. The best emulsifying activity and emulsifying stability were 43.46 m2/g and 190.35 min, the most even distribution of emulsion droplets. This indicates that the HPH treatment destroys the structure of enzymatic hydrolyzed SPC, changes its physicochemical properties, and improves its functional properties. In this study, SPC was modified by HPH and enzyme combined treatment, in order to improve the functionality and application range of SPC, and provide a theoretical basis for its high-value utilization in the food field.