345 research outputs found

    EFFECT OF SOLVENT COMPOSITION ON THE ELECTROCHEMICAL PERFORMANCE OF HIGH-VOLTAGE CATHODE LiNi0.5Mn1.5O4

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    The spinel LiNi0.5Mn1.5O4 (LNMO) is considered as an accurate cathode material for high-voltage Li-ions batteries above 4.5 V due to its high energy density, safety and eco-friendly. The electrochemical performance of spinel LNMO depends on the combability between electrode material and electrolyte. In this work, we reported the essential role of solvent compositions–carbonate solvents such as ethylene carbonate (EC), dimethyl carbonate (DMC), ethylene methyl carbonate (EMC)–in 1 M LiPF6 electrolytes on the long-term cycling test. The volumetric ratios in which the solvent compositions were varied were as follows: EC-EMC (7:3), EC-EMC (1:1), EC-DMC (1:1), EC-DMC (1:2). Result of cycling test in the solvent EC-EMC (7:3) leads to a discharge capacity of 140 mAh/g and a retention of 85 % initial capacity after 50 cycles.

    MORE ENVIRONMENTAL FRIENDLY METHOD OF LEAD RECYCLING FROM WASTE BATTERY PASTE-AN ELECTROCHEMICAL INVESTIGATION

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    Joint Research on Environmental Science and Technology for the Eart

    Kakvoća tjestenine bogate vlaknima, obogaćene prahom kore lubenice različitih veličina čestica

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    Research background. Watermelon rind, a by-product of watermelon juice processing, contains large amounts of dietary fibre and phenols with antioxidant capacity. The use of agro-industrial by-products would both improve economic benefits and reduce environmental emissions. The aim of this research is to examine the effect of the particle size of watermelon rind powder on the quality of high-fibre pasta. Experimental approach. The nutritional, physical and physicochemical quality of three samples of watermelon rind powder, sieved through three sieves with aperture size of 400, 210 and 149 μm, were analysed. Durum wheat semolina with watermelon rind powder mass fraction of 10 % were mixed and used to make pasta. Nutritional, textural and cooking quality, sensory acceptability, in vitro glycaemic index and antioxidant bioaccessibility of high-fibre pasta with added watermelon rind powder of different particle sizes were evaluated and compared. Results and conclusions. When the sieve aperture size was reduced from 400 to 149 µm, the soluble dietary fibre and total phenolic contents of watermelon rind powder were increased by 35 and 15 %, respectively, while its insoluble dietary fibre content was decreased by 21 %. Decrease in sieve aperture size from 410 to 149 µm reduced phenolic bioaccessibility of the fortified pasta from 63 to 57 %, but enhanced its predicted glycaemic index from 50 to 69. It also decreased the pasta hardness by 13 %, but improved its elongation rate and tensile strength by 13 and 40 %, respectively. The finer the particles of the watermelon rind powder, the longer the optimal cooking time, the higher the water absorption index, and the lower the cooking loss of the supplemented pasta. Consumers did not notice any significant differences in the overall acceptability among all pasta samples. Novelty and scientific contribution. The particle size of the watermelon rind powder had a major effect on nutritional value, texture and cooking quality of the fortified pasta. In particular, the predicted glycaemic index and antioxidant bioaccessibility of high-fibre pasta were significantly affected by the particle size of the dietary fibre material used in the recipe.Pozadina istraživanja. Kora lubenice, nusproizvod prerade soka lubenice, sadržava velike količine prehrambenih vlakana i fenola s antioksidacijskim svojstvima. Korištenjem agroindustrijskih nusproizvoda poboljšala bi se ekonomska učinkovitost procesa i smanjila emisija u okoliš. Svrha je ovog istraživanja bila ispitati utjecaj veličine čestica praha kore lubenice na kakvoću tjestenine bogate vlaknima. Eksperimentalni pristup. Ispitane su nutritivna, fizikalna i fizikalno-kemijska kakvoća triju uzoraka praha kore lubenice, prosijanih kroz tri sita veličine otvora 400, 210 i 149 μm. Krupica od durum pšenice pomiješana s 10 % praha kore lubenice upotrijebljena je za izradu tjestenine. Procijenjeni su i uspoređeni sljedeći parametri: nutritivna i teksturalna kakvoća te ona nakon kuhanja, senzorska prihvatljivost, in vitro glikemijski indeks i antioksidacijska biološka raspoloživost tjestenine bogate vlaknima s dodatkom praha kore lubenice različitih veličina čestica. Rezultati i zaključci. Smanjenjem veličine otvora sita s 400 na 149 µm povećali su se udjel topljivih prehrambenih vlakana za 35 % i ukupni udjel fenola u prahu kore lubenice za 15 %, dok se udjel netopljivih prehrambenih vlakana smanjio za 21 %. Smanjenjem veličine otvora sita s 400 na 149 µm smanjila se biološka raspoloživost fenola iz obogaćene tjestenine sa 63 na 57 %, ali se njezin predviđeni glikemijski indeks povećao s 50 na 69. Također se smanjila tvrdoća tjestenine za 13 %, no poboljšala se njezina rastezljivost za 13 % i vlačna čvrstoća za 40 %. Što su čestice praha kore lubenice bile sitnije, to je dulje bilo optimalno vrijeme kuhanja, veći je bio indeks upijanja vode i manji gubitak proizvoda nastao kuhanjem. Potrošači nisu primijetili nikakve bitne razlike u ukupnoj prihvatljivosti uzoraka obogaćene tjestenine. Novina i znanstveni doprinos. Veličina čestica praha kore lubenice uvelike je utjecala na nutritivnu vrijednost, teksturu i kakvoću obogaćene tjestenine nakon kuhanja. Konkretno, veličina čestica prehrambenih vlakana u materijalu korištenom u recepturi bitno je utjecala na predviđeni glikemijski indeks i antioksidacijsku biološku raspoloživost tjestenine bogate vlaknima

    In vitro antioxidant activity and content of bioactive compounds from Homalomena occulta

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    Homalomena occulta, a plant widely used in traditional Vietnamese medicine, was assessed for its antioxidant potential through DPPH radical scavenging and total antioxidant capacity methods. The results showed that Homalomena occulta exhibited significant antioxidant activities with a low IC50 value of 40.27 μg/mL, which is comparable to that of curcumin (38.50 μg/mL). Furthermore, the total antioxidant capacity of the Homalomena occulta extract was determined to be 77.48 ± 2.34 mg GA/g. To investigate the composition of the plant, various compounds including total phenolic, total flavonoid, polysaccharides, and triterpenoids were quantified using colorimetric methods with specific reagents. The content of phenolic compounds, flavonoid compounds, polysaccharides, and triterpenoids in Homalomena occulta was found to be 36.87 ± 0.42 GAE/g, 26.83 ± 0.29 mg QUE/g, 5.06 ± 0.06%, and 52.09 ± 1.77 mg Olenanoic/g, respectively. Notably, this study provides the first-ever report on the polysaccharide and total triterpenoid content of Homalomena occulta

    In vitro antioxidant activity and bioactive compounds from Calocybe indica

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    Nowadays, the use of mushrooms in medicine is ubiquitous and has achieved particular success. The antioxidants in mushrooms can deactivate free radicals. This study assesses the antioxidant potential of mushroom Calocybe indica with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging methods and the total antioxidant capacity. The mushroom’s ethanol extract exhibits acceptable activity with a low IC50 value (240.11 μg/mL), approximately 2.9 times lower than that of the mushroom Ophiocordyceps sobolifera extract. The ABTS scavenging rate of the extract is around 60% at 500 µg/mL, and the total antioxidant capacity is equivalent to 64.94 ± 1.03 mg of GA/g or 77.42 ± 0.42 μmol of AS/g.  The total phenolics, flavonoids, polysaccharides, and triterpenoids are equivalent to 29.33 ± 0.16 mg of GAE/g, 17.84 ± 0.11 mg of QUE/g (5.04 ± 0.04%), and 4.96 ± 0.04 mg of oleanolic acid/g, respectively. Specifically, the total triterpenoid content has been reported for the first time. The mushroom can have potential biomedical applications

    Polysaccharide extraction from Myxopyrum smilacifolium trunk and its antioxidant capacity

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    As a traditional medicinal plant in Vietnam, Myxopyrum smilacifolium has been used for a long history to treat cough, nervous disorders, numbness, rheumatism, and cephalalgia. Nevertheless, reports on the antioxidant activity and extraction of M. smilacifolium polysaccharides are still very rare. This study was designed to extract a high yield of polysaccharides from the M. smilacifolium trunk and characterize it. As a result, the maximum yield of the polysaccharides of 5.13 ± 0.05% was obtained with an extraction time of three hours, extraction temperature of 100 oC, the ratio of water to sample of 1:50 as extraction solution, extraction number of times 3, and the ratio of ethanol to extract volume 5:1 (v/v). Polysaccharides was characterized by Fourier transform infrared spectroscopy (FT-IR) and high-performance gel-permeation chromatography (HPGPC). The average molecular weight of extracted polysaccharides was around 3.78 × 105 Da. In vitro assays dan impressive antioxidant activities of the extracted polysaccharides, containing 0.2423 ± 0.0028 mg GA/g or 0.2142 ± 0.0007 μmol AS/g. The IC50 values of polysaccharides in the DPPH and ABTS methods were 0.89 mg/mL and 3.85 mg/mL, respectively.  These findings exhibited the potential for application or further research and development of polysaccharides from Myxopyrum smilacifolium

    Enzimatska obrada iskorištenih listića zelenog čaja i njihova primjena u proizvodnji čajnog peciva s velikim udjelom prehrambenih vlakana

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    Research background. By-products of food industry have been studied as sources of high fibre and antioxidant ingredients for healthy food products, because of their economic and environmental benefits. However, the soluble dietary fibre content of these materials is usually lower than the recommended value that is claimed to bring positive health effects. Enzymatic treatment could be an efficient method for modifying insoluble and soluble dietary fibre contents of these materials. The purpose of this study is to investigate the effects of enzymatic treatment conditions on soluble, insoluble and total dietary fibre mass fractions in spent green tea leaves, and evaluate the quality of dough and cookies when different mass fractions of untreated and treated leaves were added to the recipe. Experimental approach. The mass fractions of soluble, insoluble and total dietary fibre in spent tea leaf powder was evaluated after the leaves were treated with cellulase amount of 0−25 U/g for 0 to 2 h. Wheat flour was replaced by untreated and treated spent tea leaf powder at 0, 10, 20, 30 and 40% in cookie formulation. Textural properties of dough, proximate composition, physical properties and overall acceptability of cookies were analysed. Results and conclusions. The appropriate conditions for enzymatic treatment were enzyme loading of 20 U/g and biocatalytic time of 1.5 h, under which the mass fraction of soluble dietary fibre in spent tea leaves increased by 144.5% compared to that of the control sample. The addition of spent tea leaves led to the increase in dough hardness. Increase in the spent tea leaf amount also enhanced fibre mass fraction, antioxidant activity and hardness of cookies but reduced their overall acceptability. Moreover, the enzymatic treatment of spent tea leaves improved the soluble to total dietary fibre ratio of the cookies, which influenced their textural properties and health benefits. The cookies with added 20% untreated or treated spent tea leaves were overall accepted by the panel. Novelty and scientific contribution. For the first time, spent tea leaves have been treated with enzymes to improve their soluble to total dietary fibre ratio. The treated spent tea leaves are a new promising high-fibre antioxidant ingredient for cookie preparation.Pozadina istraživanja. Nusproizvodi prehrambene industrije ispituju se iz ekonomskih i ekoloških razloga kao izvori sastojaka s velikim udjelom prehrambenih vlakana i antioksidacijskim učinkom koji se mogu upotrijebiti u proizvodnji zdrave hrane. Međutim, udjel topljivih prehrambenih vlakana u nusproizvodima je obično manji od preporučenih vrijednosti koje mogu imati pozitivan učinak na zdravlje. Enzimatska obrada bi mogla biti učinkovita metoda modificiranja netopljivih i topljivih prehrambenih vlakana iz otpada prehrambene industrije. Svrha je ovog rada bila ispitati utjecaj različitih uvjeta enzimatske obrade na masene udjele topljivih, netopljivih i ukupnih prehrambenih vlakana u iskorištenim listićima zelenog čaja, te procijeniti kakvoću tijesta i čajnog peciva s dodatkom različitih masenih udjela obrađenih i neobrađenih listića. Eksperimentalni pristup. Maseni udjeli topljivih, netopljivih i ukupnih prehrambenih vlakana u prahu od iskorištenih listića zelenog čaja mjereni su nakon njihove obrade s 0–25 U/g celulaze tijekom 0 do 2 h. U smjesi za čajno pecivo je pšenično brašno zamijenjeno s 0, 10, 20, 30 i 40 % obrađenog ili neobrađenog praha iskorištenih listića zelenog čaja. Ispitani su tekstura tijesta te kemijski sastav, fizikalna svojstva i ukupna prihvatljivost dobivenog čajnog peciva. Rezultati i zaključci. Pri povoljnim uvjetima enzimatske obrade, a to su 20 U/g enzima i vrijeme trajanja biokatalitičkog procesa od 1,5 sata, maseni udjel topljivih prehrambenih vlakana u iskorištenim listićima zelenog čaja porastao je za 144,5 % u usporedbi s kontrolnim uzorkom. Dodatkom iskorištenih listića zelenog čaja povećala se tvrdoća tijesta. Povećanjem količine listića čaja povećali su se i maseni udjel vlakana, antioksidacijska svojstva i tvrdoća čajnog peciva, ali se smanjila njihova prihvatljivost. Osim toga, enzimatskom se obradom iskorištenih listića zelenog čaja poboljšao omjer topljivih i ukupnih vlakana u čajnom pecivu, što je utjecalo na njegovu teksturu i pozitivan učinak na zdravlje. Panel ocjenjivača je okarakterizirao čajno pecivo s dodatkom 20 % obrađenih ili neobrađenih iskorištenih listića čaja kao prihvatljive. Novina i znanstveni doprinos. Prvi put je enzimatskom obradom iskorištenih listića zelenog čaja poboljšan njihov omjer topljivih i ukupnih prehrambenih vlakana. Obrađeni iskorišteni listići zelenog čaja novi su obećavajući sastojak s antioksidacijskim svojstvima koji se može upotrijebiti u pripremi čajnog peciva

    LAYERED O3-NaFe0.5Co0.5O2 AS HIGH CAPACITY AND LOW- COST MATERIAL FOR SODIUM ION BATTERIES

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    O3-NaFe0.5Co0.5O2 layered cathode material was synthesized by solid state reaction at 900 oC followed by a quenching step in argon atmosphere. The chemical composition and morphology of synthesized material were analyzed by Atomic Absorption Spectroscopy (AAS) and Scanning Electron Microscopy (SEM). The electrochemical properties were evaluated by Cyclic Voltammetry (CV) and charge-discharge cycling. The material NaFe0.5Co0.5O2 shows the sloped discharge curves with high flat voltage plateau and excellent cycling stability. The reversible capacity of about 120 mAh/g at rate C/10 and good capacity retention after 100 cycles were obtained

    Quality of cookies supplemented with various levels of turmeric by-product powder

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    Starch production from turmeric (Curcuma longa) generates residue, which contains different nutrients, dietary fiber, and antioxidants. In this study, the by-product of turmeric starch production was dried at 50 ℃ to a moisture content of 11–12%, milled, passed through a 70-mesh sieve, and then added to cookie formulation to increase antioxidant content and activities of the fortified cookies. The ratio of turmeric by-product powder (TBP) in the cookie formulation was varied from 0 to 12%. The greater the TBP ratio in the cookie recipe was, the greater the contents of ash and dietary fiber and the antioxidant activities of the fortified cookies. At 12% TBP level, the total phenolic content, flavonoid content, 2, 2-diphenyl-1-picrylhydrazyl scavenging activity, and ferric reducing antioxidant power of the fortified cookies were increased by 6.4, 5.5, 4.7, and 6.8 times, respectively, as compared to those of the cookies without TBP supplementation. The increase in TBP ratio also enhanced the product hardness and reduced its diameter, thickness, and overall acceptability. The cookies with 9% TBP ratio were rich in antioxidants and the sensory quality was acceptable. Turmeric by-product powder was a good ingredient for antioxidant fortification in cookie products
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