9,294 research outputs found

    Sugarcane straw polyphenols as potential food and nutraceutical ingredient

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    The sugarcane processing industry generates a large amount of straw, which has a negative environmental impact, and high costs are associated with their elimination, wasting their potential bioactive value attributed to their richness in polyphenols. In this study, an ethanolic extract produced from sugarcane straw was screened for its phenolic compounds content, and the potential use of this extract in the development of a food ingredient was further evaluated. Fifty different secondary metabolites belonging to the hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids were identified by liquid chromatography–electrospray ionization–ultrahigh-resolution—quadrupole time of flight–mass spectrometry (LC-ESI-UHR-QqTOF-MS). The predominant phenolic compounds found were 4-hydroxybenzaldehyde, chlorogenic acid, and 5-O-feruloylquinic acid. The obtained extracts showed strong potential as food preservatives by exhibiting (a) antioxidant activity using both 2.2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt radical cation (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods; and (b) antimicrobial capacity, with a minimum inhibitory concentration of 50 mg/mL for Staphylococcus aureus, 74% inhibition for Bacillus cereus, and 44% for Salmonella enterica; and (c) the capacity to inhibit a food browning enzyme, tyrosinase (28–73% for 1–8 mg/ mL). Moreover, the extracts showed antidiabetic potential by inhibiting the enzymes α-glucosidase (15–38% for 1.25–5.00 mg/mL) and dipeptidyl peptidase-IV (DPP-IV) (62–114% for 0.31–5.00 mg/mL). The extract (0.625 mg/mL) also exhibited the capacity to reduce proinflammatory mediators (i.e., interleukins 6 and 8, and tumor necrosis factor alpha) when Caco-2 cells were stimulated with interleukin 1 beta. Thus, sugarcane straw extract, which is rich in phenolic compounds, showed high potential to be used in the development of food-preservative ingredients owing to its antioxidant and antimicrobial potential, and to be explored as a food supplement in diabetes prevention and as coadjuvant to reduce intestinal inflammation by reducing proinflammatory mediators.info:eu-repo/semantics/publishedVersio

    Environmental Implications of pH in a Pervious Concrete Pavement on Highway BR-319, Amazonas, Brazil

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    http://sherpa.ac.uk/romeo/issn/0973-4929/This research studies the carbonation phenomenon of cement due to the reaction of its components with water. In this chemical reaction occurs the formation of calcium carbonate and the absorption of CO2 in the atmosphere, which contributes to the reduction of the Greenhouse Effect. However, carbonation also causes pathologies such as efflorescence, staining and corrosion of steel in concrete. This research shows the results of experiments with specimens of concrete permeable, made with cement and big aggregates (calcareous stone) in the ratio of 1: 4.4 (cement:stone) and a factor of 0.3 for water / cement. The specimens were kept in contact with water containing different amounts of CO2 - distilled, ionized alkaline, carbonated, and tap water. After the experiments were carried out, an increase in pH, a mean compressive strength of 12.3 MPa and a permeability rate of 1.28 l / h was observed. The results show that the permeable concrete did not present any pathologies resulting from the carbonation during the period of the research, which recommended the same for use in road pavements.info:eu-repo/semantics/publishedVersio

    Cytotoxic, antibacterial, antioxidant, and anticholinesterasic activity of Juniperus brevifolia extracts

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    XXIII Encontro Nacional da Sociedade Portuguesa de Química. Aveiro, 12-14 de Junho 2013.The cytotoxic, antibacterial, antioxidant and anticholinesterasic (anti-AChE) activities of the methanol and acetone extracts of Juniperus brevifolia wood and bark were determined. The present study demonstrates that bark extracts of J. brevifolia are the most active and showed good antioxidant activity, lower anti-AChE activity except for the acetone extract, poor cytotoxic and antibacterial activities and absence of activity for Gram (-) bacteria.Azores University, FCT for funding CIBIO Research Unit and to DRCTC for funding CIRN

    Anti-Inflammatory properties of injectable Betamethasone-Loaded Tyramine-Modified Gellan Gum/Silk Fibroin Hydrogels

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    Rheumatoid arthritis is a rheumatic disease for which a healing treatment does not presently exist. Silk fibroin has been extensively studied for use in drug delivery systems due to its uniqueness, versatility and strong clinical track record in medicine. However, in general, natural polymeric materials are not mechanically stable enough, and have high rates of biodegradation. Thus, synthetic materials such as gellan gum can be used to produce composite structures with biological signals to promote tissue-specific interactions while providing the desired mechanical properties. In this work, we aimed to produce hydrogels of tyramine-modified gellan gum with silk fibroin (Tyâ GG/SF) via horseradish peroxidase (HRP), with encapsulated betamethasone, to improve the biocompatibility and mechanical properties, and further increase therapeutic efficacy to treat rheumatoid arthritis (RA). The Tyâ GG/SF hydrogels presented a β-sheet secondary structure, with gelation time around 2â 5 min, good resistance to enzymatic degradation, a suitable injectability profile, viscoelastic capacity with a significant solid component and a betamethasone-controlled release profile over time. In vitro studies showed that Tyâ GG/SF hydrogels did not produce a deleterious effect on cellular metabolic activity, morphology or proliferation. Furthermore, Tyâ GG/SF hydrogels with encapsulated betamethasone revealed greater therapeutic efficacy than the drug applied alone. Therefore, this strategy can provide an improvement in therapeutic efficacy when compared to the traditional use of drugs for the treatment of rheumatoid arthritis.Norte2020 project (“NORTE-08-5369-FSE000044”), REMIX project (GA 778078—REMIX—H2020-MSCA-RISE-2017) Gilson Lab, Chonbuk National University, Republic of Korea and the Frontiers of technology for theranostics of cancer, metabolic and neurodegenerative diseases (FROnTHERA), Structural Project NORTE-01-0145-FEDER-000023. The FCT distinction attributed to J.M.O. under the Investigator FCT program (number IF/01285/2015) is also greatly acknowledged. C.G. also wishes to acknowledge FCT for supporting her research (number SFRH/BPD/94277/201

    Ecotoxicity and Hemolytic Activity of Fluorinated Ionic Liquids

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    The task-specific design of ionic liquids (ILs) has emerged in several industrial and pharmaceutical applications. The family of ILs with fluorine tags equal to or longer than four carbon atoms, the fluorinated ionic liquids (FILs), combine the best properties of ILs with the ones of perfluorinated compounds, and are being designed for several specific purposes. In the pharmaceutical field, there is an urgency to search for novel antibacterial agents to overcome problems associated to antimicrobial resistances. Then, the main purpose of this work is to evaluate the environmental impact and the ability of FILs to be used as antibacterial agents against Pseudomonas stutzeri bacteria. Beyond its rare pathogenicity, these bacteria are also used as a bioremediation agent to treat several contamination sites. Then, it is important to determine which FILs have antibacterial properties, and which do not impact the bacterial growth. The biocompatibility of FILs was also evaluated through their hemolytic activity and represent a step forward the application of FILs in pharmaceutical applications. The results proved that high concentrations of FILs can have a reduced ecotoxicity and a high biocompatibility. [C8C1Im][CF3SO3] was identified as the most promising compound to be used as an antibacterial agent since it prevents the growth of bacteria at concentrations compatible with the red blood cells’ viability.publishersversionpublishe

    Brain and liver mitochondria isolated from diabeticGoto-Kakizaki rats show different susceptibility to induced oxidative stress

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    Increased oxidative stress and changes in antioxidant capacity observed in both clinical and experimental diabetes mellitus have been implicated in the etiology of chronic diabetic complications. Many authors have shown that hyperglycemia leads to an increase in lipid peroxidation in diabetic patients and animals reflecting a rise in reactive oxygen species production. The aim of the study was to compare the susceptibility of mitochondria from brain and liver of Goto-Kakizaki (12-month-old diabetic) rats (GK rats), a model of non-insulin dependent diabetes mellitus, to oxidative stress and antioxidant defenses.Brain and liver mitochondrial preparations were obtained by differential centrifugation. Oxidative damage injury was induced in vitro by the oxidant pair ADP/Fe2+ and the extent of membrane oxidation was assessed by oxygen consumption, malondialdehyde (MDA) and thiobarbituric acid reactive substances (TBARS) formation. Coenzyme Q and alpha-tocopherol contents were measured by high-performance liquid chromatography (HPLC).Brain mitochondria isolated from 12-month-old control rats displayed a higher susceptibility to lipid peroxidation, as assessed by oxygen consumption and formation of MDA and TBARS, compared to liver mitochondria. In GK rats, mitochondria isolated from brain were more susceptible to invitro oxidative damage than brain mitochondria from normal rats. In contrast, liver mitochondria from diabetic rats were less susceptible to oxidative damage than mitochondria from normal rats. This decreased susceptibility was inversely related to their alpha-tocopherol and coenzyme Q (CoQ) content.The present results indicate that the diabetic state can result in an elevation of both alpha-tocopherol and CoQ content in liver, which may be involved in the elimination of mitochondrially generated reactive oxygen species. The difference in the antioxidant defense mechanisms in the brain and liver mitochondrial preparations of moderately hyperglycemic diabetic GK rats may correspond to a different adaptive response of the cells to the increased oxidative damage in diabetes. Copyright © 2001 John Wiley & Sons, Ltd

    Effects of residues on the degradation of PHA produced from mixed microbial cultures and processed in extrusion

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    Thermal degradation upon melting is one of the major drawbacks reported for polyhydroxyalkanoates (PHA). However, the role of residues originating from the fermentation and the extraction steps on the thermal stability of this class of biopolymers still needs to be clarified. In the particular case of PHA produced from mixed microbial cultures (MMC), this topic is even less documented in the literature. Here, two polyhydroxy(butyrate-co-valerate) (PHBV) produced from MMC enriched in PHA accumulating organisms and fed with cheese whey were studied. A micro extrusion line is used to produce filaments and assess the processability and the degradation of processed PHBV. The prototype micro extrusion line allows for studying grams of materials. The two PHBV contain 18 mol% HV. PHBV was recovered with 11 wt% residues, and further submitted to a purification procedure resulting in a second biopolyester containing less than 2 wt% impurities. The thermorheological characterization of the two PHBV is first presented, together with their semicrystalline properties. Then the processing windows of the two biopolyesters are presented. Finally, the properties of extruded filaments are reported and the thermomechanical degradation of PHBV is extensively studied. The structure was assessed by wide angle X-ray diffraction, mechanical and rheological properties are reported, thermal properties are studied with differential scanning calorimetry and thermogravimetric analysis, whereas Fourier Transform Infrared spectroscopy was used to assess the impact of the extrusion on PHBV chemical structure. All results obtained with the two PHBV are compared to assess the effects of residues on both PHBV processability and degradation

    Comparative study of the whisky aroma profile based on headspace solid phase microextraction using different fibre coatings

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    A dynamic headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to ion trap mass spectrometry (GC–ITMS) method was developed and applied for the qualitative determination of the volatile compounds present in commercial whisky samples which alcoholic content was previously adjusted to 13% (v/v). Headspace SPME experimental conditions, such as fibre coating, extraction temperature and extraction time, were optimized in order to improve the extraction process. Five different SPME fibres were used in this study, namely, poly(dimethylsiloxane)(PDMS),poly(acrylate)(PA),Carboxen-poly(dimethylsiloxane)(CAR/PDMS),Carbowax-divinylbenzene(CW/DVB)and Carboxen-poly(dimethylsiloxane)-divinylbenzene (CAR/PDMS/DVB). The best results were obtained using a 75 m CAR/PDMS fibre during headspace extraction at 40◦C with stirring at 750rpm for 60min, after saturating the samples with salt. The optimised methodology was then appliedtoinvestigatethevolatilecompositionprofileofthreeScotchwhiskysamples—BlackLabel,BallantinesandHighlandClan.Approximately seventy volatile compounds were identified in the these samples, pertaining at several chemical groups, mainly fatty acids ethyl esters, higher alcohols, fatty acids, carbonyl compounds, monoterpenols, C13 norisoprenoids and some volatile phenols. The ethyl esters form an essential group of aroma components in whisky, to which they confer a pleasant aroma, with “fruity” odours. Qualitatively, the isoamyl acetate, with “banana” aroma,wasthemostinteresting.Quantitatively,significantcomponentsareethylestersofcaprilic,capricandlauricacids.Thehighestconcentration of fatty acids, were observed for caprilic and capric acids. From the higher alcohols the fusel oils (3-methylbutan-1-ol and 2.phenyletanol) are the most important ones
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