Antioxidative and Functional Properties of Pumpkin Oil Cake Globulin Hydrolysates

Cucurbitin extracted from pumpkin (Cucurbita pepo) oil cake was enzymatically hydrolysed with three different enzymes viz. alcalase, flavourzyme and pepsin. Antioxidative and functional properties of cucurbitin hydrolysates with different degrees of hydrolysis (DH) were investigated. The antioxidant activity of the hydrolysates was strongly dependent on the enzyme used. The hydrolysates obtained by alcalase and pepsin showed antioxidative potential whereas flavourzyme hydrolysates did not demonstrate these activities. Reducing power and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging activity of cucurbitin hydrolysate were positively related to DH. The highest antioxidant activity was found in the hydrolysate obtained by alcalase at DH 25.6 % [reducing power of 0.25 ± 0.01 A700 nm and ABTS scavenging activity of 3.34 ± 0.02 mmol/L Trolox equivalent antioxidant coefficients (TEAC)]. Hydrolysis by all enzymes increased the protein solubility within the studied pH range. The best emulsion activity and stability index (EAI = 143.28 ± 3.05 m²/g and ESI = 87.5 ± 1.96 min) have hydrolysates produced by flavourzyme (DH 9.2 %) whereas alcalase produced hydrolysates with the best foaming capacity (FC = 242 ± 3.21). The results demonstrate that hydrolysates produced in the present study have good functional properties as well as antioxidant activity indicating their possible use in different food systems.     

Utilization of lignocellulosic waste for ethanol production : Enzymatic digestibility and fermentation of pretreated shea tree sawdust

Enzymatic hydrolysis and fermentation methods were evaluated on alkaline peroxide pretreated shea tree sawdust conversion to ethanol. Optimum pretreatment conditions of 120 °C reaction temperature, 30 min reaction time, and 20 mL L^?1 of water hydrogen peroxide concentration (1%(v/v)H₂O₂) solubilized 679 g kg^?1 of hemicellulose and 172 g kg^?1 of lignin. 617 g kg^?1 cellulose was retained in the solid fraction. The maximum yield of reducing sugar with optimized enzyme loadings by two enzyme preparations (cellulase and β-glucosidase) was 165 g kg^?1 of dry biomass. The ethanol yield was 7.35 g L^?1 after 72 h incubation period under the following conditions: 2% cellulose loading, enzyme concentration was 25 FPU (g cellulose)^?1 loading, yeast inoculums was 10% (v/v), 32 oC, and pH 4.8. The pretreatments gave information about the hindrances caused by lignin presence in lignocellulosic materials and that hemicelluloses are better hydrolyzed than lignin, thereby enhancing enzymatic digestibility of the sawdust material.     

Phytochemical Screening and Polyphenolic Antioxidant Activity of Aqueous Crude Leaf Extract of Helichrysum pedunculatum

We evaluated the in vitro antioxidant property and phytochemical constituents of the aqueous crude leaf extract of Helichrysum pedunculatum. The scavenging activity on superoxide anions, DPPH, H₂O₂, NO and ABTS; and the reducing power were determined, as well as the flavonoid, proanthocyanidin and phenolic contents of the extract. The extract exhibited scavenging activity towards all radicals tested due to the presence of relatively high total phenol and flavonoids contents. Our findings suggest that H. pedunculatum is endowed with antioxidant phytochemicals and could serve as a base for future drugs.     

Tween 80 enhancing cellulase recyclability during activation of dissolving pulp

Abstract

Enhancing cellulase recyclability is a promising approach to reducing the high enzyme cost for activation of dissolving pulp. For this purpose, Tween 80, an amphiphilic surfactant, was employed to facilitate cellulase recovery from fibers. Results indicated that the Cellulase–Tween complex was formed (with a particle size increase of 140%) through a hydrophobic interaction. A much lower maximum binding capacity and affinity (i.e., absorption ability) of cellulase onto fibers (6.03 versus 24.3?mg protein/g cellulose and 7.45 versus 13.8?ml/mg protein) were achieved for the complex in comparison with the control. The recovered cellulase activity was increased up to 65.7% from the control one in five consecutive recycle rounds with Tween 80 addition. As a result, the recovered cellulase efficiency was improved in terms of viscosity and reactivity. Other properties, such as α-cellulose content, alkaline solubility, molecular weight distribution, morphology, and crystalline structure, were all supported by the positive effect of Tween 80 in cellulase recycling.     

Black carrot (Daucus carota ssp. sativus) juice: Processing effects on antioxidant composition and color

Black carrot, a potential source of anthocyanin pigment, has high antioxidant activity. The effect of pre-press maceration treatment with different doses of cell wall degrading enzyme pectinase (Aspergillus niger Teigh) on antioxidant composition of black carrot juice was investigated. Enzyme-assisted processing significantly (p < 0.05) improved the antioxidant composition of black carrot juice. There was an overall increase of 33% in juice yield, 27% in total phenolics and 46% in total flavonoids. The total anthocyanin content in black carrot juice was almost doubled. The in vitro total antioxidant activity in black carrot juice extracted through enzyme-assisted processing was 30.0 and 62.0 μmol TE/mL in ferric reducing antioxidant power (FRAP) and cupric reducing antioxidant capacity (CUPRAC) assays, respectively.There was 30% increase in total antioxidant activity of black carrot juice extracted with enzyme over straight pressed juice. The results indicate that tailoring of specific enzyme mixtures can yield antioxidant rich juice products. Optimizing a strategy for extraction of phenolic rich juice from black carrots can offer an opportunity for its utilization in developing novel functional beverages with enhanced color appeal and high antioxidant activity.     

Dextran: Influence of Molecular Weight in Antioxidant Properties and Immunomodulatory Potential

Dextrans (α-d-glucans) extracted from Leuconostoc mesenteroides, with molecular weights (M_W) of 10 (D10), 40 (D40) and 147 (D147) kDa, were evaluated as antioxidant, anticoagulant and immunomodulatory drugs for the first time. None presented anticoagulant activity. As for the antioxidant and immunomodulatory tests, a specific test showed an increase in the dextran activity that was proportional to the increase in molecular weight. In a different assay, however, activity decreased or showed no correlation to the M_W. As an example, the reducing power assay showed that D147 was twice as potent as other dextrans. On the other hand, all three samples showed similar activity (50%) when it came to scavenging the OH radical, whereas only the D10 sample showed sharp activity (50%) when it came to scavenging the superoxide ion. D40 was the single dextran that presented with immunomodulatory features since it stimulated the proliferation (~50%) of murine macrophages (RAW 264.7) and decreased the release of nitric oxide (~40%) by the cells, both in the absence and presence of lipopolysaccharides (LPS). In addition, D40 showed a greater scavenging activity (50%) for the hydrogen peroxide, which caused it to also be the more potent dextran when it came to inhibiting lipid peroxidation (70%). These points toward dextrans with a 40 kDa weight as being ideal for antioxidant and immunomodulatory use. However, future studies with the D40 and other similarly 40 kDa dextrans are underway to confirm this hypothesis.     

Functionality of soy protein produced by enzyme-assisted extraction

This study investigated the potential of enzymes to increase soy protein extractability without causing protein degradation. The aqueous extraction of protein was performed from defatted soy flakes on a laboratory-and pilot-plant scale. Yields of protein and reducing sugars were determined in the alkali extracts obtained with cellulases and pectinase, added alone or as cocktails. Using 5% (wt/g of protein) Multifect pectinase resulted in the best improvement of protein yields, which were 50 and 17% greater than the controls in laboratory- and pilot-plant-scale trials, respectively. This enhanced protein extraction was accompanied by an increased reducing sugar content in the aqueous extract compared with the control. Under the conditions tested, no enzyme cocktail markedly increased the protein yield compared with the use of single enzymes. The solubility curve for Multifect pectinase-treated soy protein isolate (SPI) was typical of SPI at pH 2–10. Its foam stability significantly improved, but the emulsification properties declined. Multifect pectinase markedly reduced the viscosity of SPI. SDS-PAGE showed that the α’ and α subunits of β-conglycinin were modified, and glycoprotein staining showed that these modifications were probably due to a protease secondary activity in the pectinase preparation. One cellulase and one pectinase were identified as effective in modifying the protein and reducing sugar extractablity from the defatted soy flakes.     

Effect of depolymerized mango pulp as a stabilizer in,oil-in-water emulsion containing sodium caseinate

The effect of pectin in mango pulp in term of reducing sugar (45–100 mg glucose/g fresh weight) on oil-in-water emulsion stability was investigated in systems containing sodium caseinate (0–6% (w/w)) and oil (20% (w/w)). Emulsion stability was evaluated from average droplet size, viscosity and creaming stability. Results showed that emulsion made from enzyme treated mango pulp had small average droplet size which led to more creaming stability than emulsion made from non-enzyme treated mango pulp. Increasing degree of hydrolysis for pectin in mango pulp significantly affected creaming stability (p ≤ 0.05) but had no significant effect on average droplet size of the emulsion (p > 0.05). The emulsion with excellent stability was found that made from depolymerized mango pulp with reducing sugar content of 60 mg glucose/g fresh weight (DP 60) and 2% (w/w) sodium caseinate. In addition, it was found that DP 60 could be used as an alternative stabilizer for oil-in-water food emulsion.     

Antioxidant activity of burdock (Arctium lappa Linné): Its scavenging effect on free-radical and active oxygen

The antioxidant activity and free-radical and active oxygen-scavenging activity of burdock extracts were investigated. Of the solvents used for extraction, water yielded the greatest amount of extract that exhibited the strongest antioxidant activity. Water extracts of burdock (WEB) and hot water extracts of burdock (HWEB) exhibited comparable and marked activity on inhibition of linoleic acid peroxidation, indicating that heat treatment did not alter the antioxidant activity of WEB. WEB and HWEB produced significantly lower (P<0.05) malondialdehyde (MDA) in both linoleic acid and liposome model systems than did the control. Moreover, mixtures of tocopherol (Toc), WEB, and HWEB exhibited a remarkable synergistic antioxidant effect in a liposome system; WEB and HWEB thus potentiated the action of Toc. Furthermore, WEB and HWEB displayed a marked inhibitory effect on lipid peroxidation of rat liver homogenate in vitro. WEB and HWEB exhibited an 80% scavenging effect on α,α-diphenyl-β-picrylhydrazyl radical and marked reducing power, indicating that WEB and HWEB act as primary antioxidants. Both extracts at a dose of 1.0 mg exhibited a 60.4–65.0% scavenging effect on superoxide and an 80.5% scavenging effect on hydrogen peroxide. They also showed a marked scavenging effect on the hydroxyl radical. These results revealed that WEB and HWEB are also active as oxygen scavengers and as secondary antioxidants. Based on these results, termination of free-radical reactions and quenching of reactive oxygen species in burdock extracts are suggested to be, in part, responsible for the antioxidant activity of burdock extracts.     

Antioxidant activity of crude tannins of canola and rapeseed hulls

The antioxidant activity of crude tannins of canola and rapeseed hulls was evaluated by β-carotene-linoleate, α,α-diphenyl-β-picrylhydrazyl (DPPH) radical, and reducing power assays. Crude tannins were extracted from three samples of Cyclone canola (high-tannin) hulls and Kolner, Ligaret, and Leo Polish rapeseed (low-tannin) hulls with 70% (vol/vol) acetone. The total phenolic content in crude tannin extracts ranged between 128 and 296 mg of sinapic acid equivalents per 1 g of extract. The ultraviolet spectra of methanolic solution of canola extracts showed two absorption maxima (282 and 309 nm), whereas those of rapeseed extracts exhibited a single maximum (326 nm). Crude tannins isolated from canola hulls exerted significantly (P<0.025) greater antioxidant activity than those from rapeseed in all three assays. The scavenging effect of all crude tannins, at a dose of 1 mg, on the DPPH radical ranged from 35.2 to 50.5%. The reducing power of Cyclone canola hull extracts on potassium ferricyanide was significantly (P≤0.0025) greater than that of rapeseed hull extracts, and the observed data correlated well (r=0.966; P=0.002) with the total content of phenolics present.     

The Effect of Using Micro-Clustered Water as a Polymer Medium

The aim of the study was to investigate the changes within the physicochemical properties of gelatin, carrageenan, and sodium alginate hydrosols prepared on the basis of micro-clustered (MC) water. The rheological parameters, contact angle and antioxidant activity of hydrosols were investigated. Moreover, the pH, oxidation–reduction potential (ORP) and electrical conductivity (EC) were measured. The hydrosols with MC water were characterized by a lower pH, decreased viscosity, a lower contact angle, and only slightly lower antioxidant activity than control samples. The results showed that hydrosol’s properties are significantly changed by MC water, which can lead to enhancement of its applicability but requires further investigation.     

Saccharification of microcrystalline cellulose by cellulase of Morchella conica mushroom mycelium in comparison with a commercial cellulase

A comparison was made of the hydrolysis of microcrystalline cellulose Avicel using the cellulolytic complex of the ascomycete Morchella conica and a commercial cellulase. An enzyme concentration of 1 U AVase mg^?1 substrate gave the best results during the hydrolytic processes. At 24 h, the M. conica enzyme complex achieved 35.5% and the commercial cellulase 31·2% saccharification, with glucose 84·2% and 52% of the total reducing sugars liberated, respectively. The specific rates of hydrolyses were 0·77 and 0·14 h^?1 for reducing sugars and 0·54 and 0·12 h^?1 for glucose formation with M. conica and the commercial cellulase, respectively. At 96 h, the degree of saccharification reached 46% for M. conica and 49% for the commercial cellulase, with glucose 76·5% and 65·9% of the total reducing sugars liberated, respectively. Both the complexes were quite stable with a residual activity of 62% CMCase and 47% AVase for M. conica, and 74% CMCase and 57% AVase for the commercial cellulase at 96 h of hydrolysis. The qualitative analysis of the hydrolysis products by TLC indicated, for M. conica, an earlier appearance of cellobiose, which was quickly hydrolyzed to glucose.     

Optimization of the enzymatic hydrolysis conditions of steam‐exploded wheat straw for maximum glucose and xylose recovery

BACKGROUND: The enzymatic hydrolysis of steam‐exploded wheat straw using commercial enzyme complexes has been studied. A cellulase enzyme complex (Accellerase 1500), along with specific xylanase complements (Accellerase‐XC and Accellerase‐XY) provided by Genencor, have been used to enhance glucose and xylose recovery. A systematic study with response surface methodology (RSM) was used to check the effect of the operating conditions: pH (4–5), temperature (50–60 °C) and enzyme/substrate ratio (0.1–0.5 mL g_cellulose^?1) on the enzymatic hydrolysis with Acellerase 1500 to maximize the sugar yield. Xylanases were used as complements to increase the release of xylose. RESULT: Statistical results from ANOVA analysis demonstrated that the enzymatic hydrolysis was clearly improved by temperature and enzyme/substrate ratio. The optimum conditions for higher glucose and xylose releases were obtained with the higher enzyme dosage ratio (0.5 mL g^?1_cellulose), 50 °C and pH 4. CONCLUSION: Model validation at optimum operating conditions showed good agreement between the experimental results and the predicted responses for a confidence level of 95%. The use of the xylanase complements, Accellerase‐XY (accessory xylanase enzyme complex) and Accellerase‐XC (accessory xylanase/cellulase enzyme complex), increases the conversion of hemicellulose. Accellerase‐XC supplementation was more effective, obtaining an increase in yields of glucose and xylose of 11.8% and 23.6%, respectively, using a dosage of 0.125 mL g^?1_cellulose. © 2012 Society of Chemical Industry     

In vitro antioxidant activity of enzymatic hydrolysates prepared from abalone (Haliotis discus hannai Ino) viscera

Pacific abalone (Haliotis discus hannai Ino) viscera, which are normally discarded as byproducts, were hydrolyzed with five commercially available proteases, including alkali protease, papain, neutral protease, pepsin, and trypsin. The hydrolysates obtained were fractionated using ultrafiltration membrane bioreactor system. The resulting hydrolysate fractions were investigated for their antioxidant activities, including the scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, the scavenging effect on hydroxyl radical, and the reducing power. Results showed that the hydrolysate fractions were effective antioxidants, and the antioxidant activity of the hydrolysates was related to the enzyme type employed. As byproducts, abalone viscera can be used as a potential source of antioxidant peptides.     

Effect of Enzymatic Hydrolysis on the Antioxidant Activity of Red and Green Seaweeds and Characterization of the Active Extracts

In the present study, the effect of enzymatic hydrolysis on the antioxidant activity of three red seaweeds (Chondria cornuta, Chondria dasyphylla, and Murrayella periclados) and two green seaweeds (Cladophora sp. and Ulva lactuca) from the Kuwait coast were evaluated. The seaweeds were hydrolyzed with five carbohydrases and three proteases, and the resulting extracts were tested for antioxidant activity. The total phenolic content and yield of the extracts varied greatly depending upon the species and enzyme used for hydrolysis. Of the 40 enzymatic extracts screened for antioxidant activity, the Viscozyme and Alcalase extracts of M. periclados, Neutrase and Ultraflo extracts of Cladophora sp., and Neutrase extracts of C. cornuta had high antioxidant activity compared to other enzymatic extracts in various in vitro assays. Fractionation of the extracts revealed that the radical scavenging and reducing power of the extracts were mainly due to phenolic fractions. In contrast, the iron-chelating ability was mainly due to protein fractions. The level of prevention of lipid oxidation in the liposome model system varied for different fractions of extracts and did not correlate with total phenolic content and other antioxidant properties. The results of the study show that, by hydrolyzing seaweeds with specific enzymes, customized seaweed extracts with specific bioactivity could be obtained.     

Total Phenolic Contents and Antioxidant Capacities of Selected Chinese Medicinal Plants

Antioxidant capacities of 56 selected Chinese medicinal plants were evaluated using the Trolox equivalent antioxidant capacity (TEAC) and ferric reducing antioxidant power (FRAP) assays, and their total phenolic content was measured by the Folin-Ciocalteu method. The strong correlation between TEAC value and FRAP value suggested that the antioxidants in these plants possess free radical scavenging activity and oxidant reducing power, and the high positive correlation between antioxidant capacities and total phenolic content implied that phenolic compounds are a major contributor to the antioxidant activity of these plants. The results showed that Dioscorea bulbifera, Eriobotrya japonica, Tussilago farfara and Ephedra sinica could be potential rich sources of natural antioxidants.     

Proximate Composition and Antioxidant Potential of Leaves from Three Varieties of Mulberry (Morus sp.): A Comparative Study

In this study, leaves of three indigenous varieties of Mulberry namely, Morus alba L., Morus nigra L. and Morus rubra L. were investigated for their antioxidant potential and their proximate composition was determined. The yields of 80% methanolic extracts ranged between 8.28–13.89%. The contents of total phenolics (TPC), total flavonoids (TFC) and ascorbic acid (AA) ranged between 16.21–24.37 mg gallic acid equivalent (GAE)/g, 26.41–31.28 mg rutin equivalent (RE)/g and 0.97–1.49 mg/g, respectively. The antioxidant activity of leaf extracts was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH^•) radical scavenging actity, 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid (ABTS^•+) radical cation scavenging capacity and ferric ion reducing power and values ranged between 1.89–2.12, 6.12–9.89 and 0.56–0.97 mM Trolox equivalent/g of dried leaves, respectively. The investigated features reveal good nutritive and antioxidant attributes of all the varieties with mutually significant differences.     

Viscosity of the solutions of lithium acetate in water and aqueous methyl acetate

The viscosity of water and aqueous methyl acetate (mole fraction  0.05) solutions lithium at 35, 40 and 50°, and at concentrations varying from 0.02 to 0.1 M are reported. The relative-viscosity coefficient has been calculated, and the A and B parameters of Jones-Dole equation have been estimated. The activation energy of the viscous flow at C  0.04 M for both the solutions have been estimated. The results are discussed in terms of the structure of the solvents.     

Comparative study on the antioxidant and nitrite scavenging activity of fruiting body and mycelium extract from Pleurotus ferulae

We investigated the effects of the antioxidant and the nitrite scavenging activities of the extracts from Pleurotus ferulae fruiting body grown on the solid state using corn cob and activated bleaching earth (CCABE media) and its mycelium grown in the liquid state. The total phenol and polysaccharide concentrations in hot water extract of fruiting body were approximately 3.6- and 4.3-fold higher than those of the mycelium. Using the hot water extract of fruiting body, the maximum DPPH radical scavenging activity at 9 mg/mL, hydroxyl radical scavenging activity at 12mg/mL, reducing power at 12 mg/mL, and chelating ability at 12 mg/mL were obtained, 80.5%, 72.4%, 0.99 OD (700 nm), and 77.0%, respectively. However, in the case of hydrogen peroxide scavenging activity, the ethanol extract was the highest, 78.7% at 12 mg/mL. The maximum nitrite scavenging activity was obtained, 89.7% at 6 mg/mL of hot water extract from fruiting body. Hot water extracts were more effective than ethanol extracts in scavenging activity on DPPH radicals and hydroxyl radical scavenging, reducing power, and chelating activity of ferrous, whereas ethanol extracts were more effective in hydrogen peroxide scavenging activity as evidenced by their lower EC₅₀ values. These results indicate that the hot water extract of P. ferulae fruiting body using CCABE media has good potential to be used as a source of materials or additives for oxidation suppressant in food, cosmetics and drug compositions.     

Influence of the viscosity of film-forming solutions on light losses in nanodimensional coatings based on SiO2

The dependence of light losses in nanodimensional coatings obtained by sol-gel technology on the viscosity of film-forming solutions and on their light absorption at wavelengths of 315, 364, and 400 nm has been considered. It is shown that the number of inclusions and light losses in the coatings are proportional to the viscosity of the solutions. The absence of a reliable correlation between the viscosity and light losses in a film-forming solution is accounted for by the deviation of the shape of the particles from a spherical one. Using computer modeling, it has been established that the average size of particles in a coating does not exceed 5 nm and their arrangement is friable. The light losses in the coatings studied are sensitive to the content of oxides in a film-forming solution and the rate of its deposition onto the substrate.