1,480 research outputs found
Adsorption of fluorobenzene onto granular activated carbon: Isotherm and bioavailability studies
The adsorption of a recalcitran fluoroaromatic compound, fluorobenzene (FB), onto granular activated carbon (GAC) was evaluated. The respective isotherm was obtained and the Langmuir, Freundlich and Redlich–Peterson models were fitted to the experimental data, with the Redlich–Peterson model giving the best fitting. Freundlich model also provided a good fit but the Langmuir model could not adequately fit the experimental data, especially at high FB concentrations. Maximal adsorption capacity of FB onto GAC was foundto be 388 mg of FB per gram of GAC. The reversibility of the adsorption of FB onto GAC was investigated, both in the absence and presence of microorganisms. Abiotic desorption of FB occurred to a small extent (between 3% and 22%, for amounts of FB initially adsorbed to the GAC between 37 and 388 mg g 1), and bioregeneration of GAC was shown to occur when the matrix was exposed to a FB degrading culture, with 58–80% of the adsorbed FB being biodegraded. A residual amount of FB showed not to be bioavailable,
suggesting that part of the adsorbed FB may be irreversibly bound. The fraction of the non-bioavailable FB increased at higher amounts of adsorbed FB, from 19% to 33%. The results indicate that the GAC employed in this study has a good capacity to adsorb FB and that bioregeneration of this matrix is a feasible process
Extratos fenólicos de flores de Rubus ulmifolius Schoot: caracterização química, microencapsulação e incorporação em iogurtes para benefícios antioxidants
Rubus ulmifolius Schoot (Rosaceae), conhecida como amora silvestre, é um arbusto perene
encontrado em habitats silvestres e cultivados da Europa, Ásia e África do Norte.
Tradicionalmente é conhecido pelas suas propriedades medicinais, incluindo atividade
antioxidante. Neste trabalho caracterizaram-se quimicamente dois extratos fenólicos obtidos a
partir de botões florais de R. ulmifolius, decocção e extrato hidroalcoólico, tendo sido
identificados vários compostos fenólicos, maioritariamente derivados de elagitaninos
nomeadamente, os isómeros sanguiin H-10 e lambertianina.
Comparativamente à decocção, o extrato hidroalcoólico apresentou um conteúdo em
compostos fenólicos superior e uma maior atividade antioxidante. A sua forma liofilizada foi a
escolhida para microencapsular pela técnica de spray seguida de coagulação tendo-se
produzido microesferas de alginato que foram posteriormente incorporadas num iogurte
natural. Os resultados obtidos mostraram que o extrato microencapsulado originou produtos
com atividade antioxidante superior e com melhor preservação desta ao longo do tempo.
Ambas as formas (extrato direto e microencapsulado) mostraram maior atividade que o
controlo. Em síntese, os resultados obtidos demonstraram o potencial antioxidante do extrato
hidroalcoólico R. ulmifolius e a eficiência da microencapsulação para a sua preservação,
abrindo assim possibilidades para a sua exploração em aplicações na indústria alimentar.Fundação para a Ciência e a Tecnologia (FCT, Portugal) pelo apoio financeiro ao CIMO
(projeto estratégico PEst-OE/AGR/UI0690/2011) e ao LSRE (projeto estratégico PEst-
C/EQB/LA0020/2011). L. Barros agradece ao FCT, POPH-QREN e FSE pelo seu contrato de
investigação no âmbito do “Programa Compromisso com Ciência-2008”.O GIP-USAL é financeiramente suportado pelo governo espanhol através do Programa Consolider-Ingenio 2010 (FUN-C-FOOD, CSD2007-00063)
Phenolic extracts of Rubus ulmifolius Schoot flowers: characterization, microencapsulation and incorporation into yogurts as nutraceutical sources
Rubus ulmifolius Schott (Rosaceae), known as wild blackberry, is a perennial shrub found in wild and
cultivated habitats in Europe, Asia and North Africa. Traditionally, it is used for homemade remedies
because of its medicinal properties, including antioxidant activity. In the present work, phenolic extracts
of R. ulmifolius flower buds obtained by decoction and hydroalcoholic extraction were chemically and
biologically characterized. Several phenolic compounds were identified in both decoction and
hydroalcoholic extracts of flowers, ellagitannin derivatives being the most abundant ones, namely the
sanguiin H-10 isomer and lambertianin. Additionally, comparing with the decoction form, the
hydroalcoholic extract presented both higher phenolic content and antioxidant activity.
The hydroalcoholic extract was thereafter microencapsulated in an alginate-based matrix and
incorporated into a yogurt to achieve antioxidant benefits. In what concerns the performed
incorporation tests, the obtained results pointed out that, among the tested samples, the yoghurt
containing the microencapsulated extract presented a slightly higher antioxidant activity, and that both
forms (free and microencapsulated extracts) gave rise to products with higher activity than the control.
In conclusion, this study demonstrated the antioxidant potential of the R. ulmifolius hydroalcoholic
extract and the effectiveness of the microencapsulation technique used for its preservation, thus
opening new prospects for the exploitation of these natural phenolic extracts in food application
Patellar Luxation in Small Animals
This study describes lesions that occur in the stifle joints of dogs with patellar luxation. These lesions are associated with the animal’s age, body weight and degree of luxation. It also reports on the rate of re-dislocation. The patellar lesions found include articular cartilage erosion, subchondral bone exposure, a flattened or concave patellar surface and enthesophytes. Extrapatellar lesions included synovitis, osteophytes, blunting of the trochlear groove, an absent trochlea, erosion of the condylar margins, capsule thickening, a long digital extensor tendon injury, “joint mice,” flap formation, cranial cruciate ligament rupture and meniscal prolapse. Such lesions were frequently found in animals with grade II or III luxation that were aged 24 months or older; they were more severe in dogs weighing more than 15 kg. Patellar luxation causes changes that favour articular degeneration and should be treated surgically. Conservative treatment relieves pain but does not address tissue alterations
Microwave-assisted extraction of phenolic acids and flavonoids and production of antioxidant ingredients from tomato: a nutraceutical-oriented optimization study
The production of natural extracts requires suitable processing conditions to maximize the preservation of the bioactive ingredients. Herein, a microwave-assisted extraction (MAE) process was optimized, by means of response surface methodology (RSM), to maximize the recovery of phenolic acids and flavonoids and obtain antioxidant ingredients from tomato. A 5-level full factorial Box-Behnken design was successfully implemented for MAE optimization, in which the processing time (t), temperature (T), ethanol concentration (Et) and solid/liquid ratio (S/L) were relevant independent variables. The proposed model was validated based on the high values of the adjusted coefficient of determination and on the non-significant differences between experimental and predicted values. The global optimum processing conditions (t=20 min; T=180 ºC; Et=0 %; and S/L=45 g/L) provided tomato extracts with high potential as nutraceuticals or as active ingredients in the design of functional foods. Additionally, the round tomato variety was highlighted as a source of added-value phenolic acids and flavonoids.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (PEst-OE/AGR/UI0690/2014), REQUIMTE (UID/QUI/50006/2013 - POCI/01/0145/FERDER/007265), J. Pinela (SFRH/BD/92994/2013) and L. Barros (SFRH/BPD/107855/2015); FCT/MEC and FEDER under Programme PT2020 for financial support to LSRE (UID/EQU/50020/2013), and to QREN, ON2 and FEDER (NORTE-07-0162-FEDER-000050); to the Xunta de Galicia for financial support for the post-doctoral researcher of M.A. Prieto
Identification of vertebrate type steroid hormones in the shrimp Penaeus japonicus by tandem mass spectrometry and sequential product ion scanning
The identification of testosterone, pregnelonone, and 17α-hydroxyprogesterone by tandem mass spectrometry and of progesterone by sequential product ion scanning in the shrimp gonads of Penaeus japonicus is described. The identification of these substances in biological samples is usually done by gas chromatography-mass spectrometry and involves several liquid chromotographic purification steps followed by derivatization. The utilization of tandem mass spectrometry in this analysis has simplified considerably the sample pretreatment and provided a very simple method of screening these substances in complex mixtures
Optimization of microwave-assisted extraction of hydrophilic and lipophilic antioxidants from a surplus tomato crop by response surface methodology
Tomato is the second most important vegetable crop worldwide and a rich source of industrially interesting antioxidants. Hence, the microwave-assisted extraction of hydrophilic (H) and lipophilic (L) antioxidants from a surplus tomato crop was optimized using response surface methodology. The relevant independent variables were temperature (T), extraction time (t), ethanol concentration (Et) and solid/liquid ratio (S/L). The concentration-time response methods of crocin and β-carotene bleaching were applied, since they are suitable in vitro assays to evaluate the antioxidant activity of H and L matrices, respectively. The optimum operating conditions that maximized the extraction were as follows: t, 2.25 min; T, 149.2 ºC; Et, 99.1 %; and S/L, 45.0 g/L for H antioxidants; and t, 15.4 min; T, 60.0 ºC; Et, 33.0 %; and S/L, 15.0 g/L for L antioxidants. This industrial approach indicated that surplus tomatoes possess a high content of antioxidants, offering an alternative source for obtaining natural value-added compounds. Additionally, by testing the relationship between the polarity of the extraction solvent and the antioxidant activity of the extracts in H and L media (polarity-activity relationship), useful information for the study of complex natural extracts containing components with variable degrees of polarity was obtained.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (PEst-OE/AGR/UI0690/2014), REQUIMTE (UID/QUI/50006/2013) and J. Pinela (SFRH/BD/92994/2013); to FCT/MEC and FEDER under Programme PT2020 for financial support to LSRE (UID/EQU/50020/2013), and to QREN, ON2 and FEDER (Project NORTE-07-0162-FEDER-000050); to the Xunta de Galicia for financial support for the post-doctoral researcher of M.A. Prieto
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