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1.
PLoS Negl Trop Dis ; 14(3): e0008116, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32142519

RESUMO

Rabies is a lethal zoonotic encephalomyelitis that causes an estimated 59,000 human deaths yearly worldwide. Although developing countries of Asia and Africa bear the heaviest burden, surveillance and disease detection in these countries is often hampered by the absence of local laboratories able to diagnose rabies and/or the difficulties of sample shipment from low-access areas to national reference laboratories. Filter papers offer a convenient cost-effective alternative for the sampling, shipment, and storage of biological materials for the diagnosis of many pathogens including rabies virus, yet the properties of diagnostic tests using this support have not been evaluated thoroughly. Sensitivity and specificity of molecular diagnosis of rabies infection using a reverse transcription followed by a hemi-nested polymerase chain reaction (RT-hn-PCR) either directly on brain tissue or using brain tissue dried on filter paper were assessed on 113 suspected field animal samples in comparison to the direct fluorescent antibody test (FAT) recommended by the World Health Organization as one of the reference tests for rabies diagnosis. Impact of the duration of the storage was also evaluated. The sensitivity and the specificity of RT-hn-PCR i) on brain tissue were 96.6% (95% CI: [88.1-99.6]) and 92.7% (95% CI: [82.4-98.0]) respectively and ii) on brain tissue dried on filter paper 100% (95% CI: [93.8-100.0]) and 90.9% (95% CI: [80.0-97.0]) respectively. No loss of sensitivity of RT-hn-PCR on samples of brain tissue dried on filter paper left 7 days at ambient temperature was detected indicating that this method would enable analyzing impregnated filter papers sent to the national reference laboratory at ambient temperature within a 1-week shipment time. It could therefore be an effective alternative to facilitate storage and shipment of samples from low-access areas to enhance and expand rabies surveillance.


Assuntos
Encéfalo/virologia , Dessecação/métodos , Técnicas de Diagnóstico Molecular/métodos , Vírus da Raiva/isolamento & purificação , Raiva/diagnóstico , Manejo de Espécimes/métodos , África , Ásia , Países em Desenvolvimento , Reação em Cadeia da Polimerase , Vírus da Raiva/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade
2.
Chemosphere ; 249: 126108, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32087450

RESUMO

Advanced dewatering technologies with moisture content from nearly 80% to below 60% have attracted widespread attention in the field of municipal dewatered sludge disposal. The usage of the correct types of oxidants and the degradation of key component on the effect of secondary advanced dewatering performance is a rising focus. In this study, three types of typical oxidants (Fenton's reagent, H2O2, and KMnO4) were used to pre-treat dewatered sludge directly, then advanced dewatering performance, conversion rate of bio-bound water and decomposition trend of various organic biomass were analysed. Results showed that final moisture content of Fenton's reagent group reduced to below 50% with exposure to the compression of 1000 kPa for 30 min. Different oxidants that were characterized by selective oxidizability and, compared with other oxidants, mainly decomposed proteins, lipids and humic substances, the key component of polysaccharides, which may combine with the most water were primarily decomposed by Fenton's reagent. This promoted the conversion from bio-bound water to free water and advanced dewatering performance significantly. From a morphological perspective, the ratio of dissolved polysaccharides from three layers showed Pellets: tightly bound EPS (T-EPS): loosely bound EPS (L-EPS) = 52.28%-66.56%: 8.37%-12.75%: 23.15%-39.08%, and due to the cell-breaking capacity, Fenton's reagent could mainly promote the release of intracellular polysaccharides-bound water.


Assuntos
Polissacarídeos , Eliminação de Resíduos Líquidos/métodos , Dessecação/métodos , Substâncias Húmicas , Peróxido de Hidrogênio , Ferro , Oxidantes , Oxirredução , Estresse Oxidativo , Esgotos , Água
3.
Environ Sci Pollut Res Int ; 27(8): 8696-8706, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31912396

RESUMO

Proteins of extracellular polymeric substances (EPS) in sewage sludge play a key role in the sludge dewatering. Ethanol can denature proteins and improve sludge dewaterability. In this study, ethanol was used to precondition and combined with Fe3+ and rice husk (RH) for dewatering enhancement. The experimental results of the capillary suction time (CST) reduction efficiency indicated that the sewage sludge pretreated with ethanol and Fe3+-RH revealed well cooperative formation mechanism with regard to dewatering performance. Using the response surface methodology (RSM) determined that CST reduction efficiency of sewage sludge reached 78.5% under optimal conditions of ethanol 25.21 g/g dry solid (DS), Fe3+ 185.70 mg/g DS, and RH 406.02 mg/g DS, respectively. Moreover, the results showed that the composite conditioner is effective for the specific resistance to filtration decreased from initial 1.66E + 13 m/kg to 2.44E + 11 m/kg. The analysis of EPS showed that extractable proteins in EPS increased to maximum when the sludge was pretreated by Fe3+-RH because EPS were destroyed and proteins in EPS were released. After the addition of ethanol, extractable protein content was reduced because of protein precipitation and released interstitial water and bound water. The sludge morphology analysis indicated that the RH as a skeleton builder provided the outflow passages, which enhanced the dewatering performance of sludge. From these results, the combination treatment of ethanol and Fe3+-RH is a promising synergetic strategy to enhance the dewaterability of sewage sludge.


Assuntos
Dessecação/métodos , Etanol , Oryza , Esgotos , Eliminação de Resíduos Líquidos/métodos , Ferro , Oxirredução , Água
4.
J Sci Food Agric ; 100(4): 1635-1642, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31802498

RESUMO

BACKGROUND: Recently, consumers' demand on high quality dried fruit or vegetable products have increased dramatically. The instant controlled pressure drop (DIC) dried products have attracted consumers' attention due to its unique sensory characteristics. The product quality, especially the appearance quality of the DIC products, is influenced closely by water status and water distribution in the material, which is rarely reported in the literatures. In this study, a comparison system for the apple cubes with or without the moisture equilibrium process (MEP) was established to explain the effect of the MEP on the expansion behavior of the DIC dried apple cube. RESULTS: The results showed that the MEP could induce a more homogenous spatial distribution of water in the semi-dried apple cube after pre-drying. Meanwhile, the MEP treated and DIC dried apple cubes showed better quality in terms of the appearance and texture properties including high porosity (71.77%), large pores (maximum pore size of 1.55 mm), and thin pore walls (pore wall thickness of 0.079 mm). CONCLUSION: The MEP was approved to be a compulsory treatment to achieve the DIC dried apple cubes with good expansion behavior. © 2019 Society of Chemical Industry.


Assuntos
Dessecação/métodos , Conservação de Alimentos/métodos , Frutas/química , Malus/química , Dessecação/instrumentação , Conservação de Alimentos/instrumentação , Porosidade , Pressão , Água/análise
5.
Chemosphere ; 241: 125096, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629242

RESUMO

In this study, the acidic-modified bentonite (AMB) was developed to enhance conditioning and dewatering processes of anaerobically digested sludge (ADS) for the first time and its performance was compared with inorganic salts, e.g. FeCl3, AlCl3, Al2(SO4)3 and Fe2(SO4)3. AMB structural changes were investigated employing XRD, XRF, FT-IR and specific surface area tests. AMB reduced the specific resistance to filterability (SRF), capillary suction time (CST) and time to filter (TTF) of the sludge by 95.8%, 90.4% and 80.8%, respectively. Moreover, it reduced the sludge compressibility and increased filtration yield significantly. Also, sludge conditioning with the AMB resulted in a significant increase in the sludge particles size and formation of denser and stronger flocs. In order to evaluate the related sludge conditioning mechanism, zeta potential, bound water, extracellular polymeric substances (EPS) and XRF tests were conducted. It was determined that AMB acts as physical and chemical conditioner. Dewatering of conditioned sludge with AMB utilizing a filter press resulted in the sludge with 41% dry solids (DS). In addition, the economic survey showed that the cost of conditioning by using AMB is $ 33.79 USD/t DS. In general, it can be concluded that AMB has an effective performance in conditioning and dewatering of anaerobically digested sludge and is economically affordable in comparison to common polymers.


Assuntos
Anaerobiose , Bentonita/química , Dessecação/métodos , Esgotos/química , Bentonita/economia , Filtração , Tamanho da Partícula , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Food Chem ; 310: 125637, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31791727

RESUMO

Reduction of bioactive compounds sensitive to heat, light and oxygen could be attributed to drying. The effectiveness of microwave pretreatment at 525 or 420 W and the ohmic heating at 17.5 V/cm over the properties of beetroot powder were compared. This study aimed to develop novel hybrid drying methods. The effects of microwave and ohmic heating pre-treatment and subsequent microwave-convection drying were studied. Several investigations were performed, such as phenolic content, antioxidant activity, betalains content and color. The samples pretreated by microwave have registered higher polyphenols content and antioxidant capacity than those ohmically heated. The ohmic heating pretreated samples registered highest values for ΔL = 7.33-7.65 and ΔH = 8.18-10.02. Confocal microscopy reveals that the MW heating favors cellular lysis and cell content agglutinates. In conclusion, even if the MW preheating has certain disadvantages, in some cases it provides increased bioavailability generated by the vegetal cell disruption and the release of the bioactive compounds.


Assuntos
Beta vulgaris/química , Dessecação/métodos , Pós/química , Antioxidantes/análise , Antioxidantes/química , Betacianinas/análise , Betalaínas/análise , Betalaínas/química , Cor , Convecção , Temperatura Alta , Micro-Ondas , Ácidos Picolínicos/análise , Polifenóis/análise , Polifenóis/química
7.
Chemosphere ; 241: 125116, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31683429

RESUMO

Oscillating cycles of dewatering (termed drying) and rewetting during managed aquifer recharge (MAR) are used to maintain infiltration rates and could also exert an influence on subsurface microbial structure and respiratory processes. Despite this practice, little knowledge is available about changes to microbial community structure and trace organic chemical biodegradation potential in MAR systems under these conditions. A biologically active two-dimensional (2D) synthetic MAR system equipped with automated sensors (temperature, water pressure, conductivity, soil moisture, oxidation-reduction potential) and embedded water and soil sampling ports was used to test and model these important subsurface processes at the meso-scale. The fate and transport of the antiepileptic drug carbamazepine, the antibiotics sulfamethoxazole and trimethoprim, and the flame retardant tris (2-chloroethyl) phosphate were simulated using the finite element analysis model, FEFLOW. All of these compounds exhibit moderate to poor biodegradability in MAR systems. Within the operational MAR scenario tested, three episodic drying cycles spanning between 18 and 24 days were conducted over a period of 184 days. Notably, cessation of flow and partial dewatering of the 2D synthetic aquifer during dry cycles caused no measurable decrease in soil moisture content beyond the near-surface layer. The episodic flow introduction and dewatering cycles in turn had little impact on overall trace organic chemical biotransformation behavior and soil microbial community structure. However, spatial differences in oxidation-reduction potential and soil moisture were both identified as significant environmental predictors for microbial community structure in the 2D synthetic aquifer.


Assuntos
Biodegradação Ambiental , Dessecação/métodos , Água Subterrânea/química , Poluentes Químicos da Água/química , Molhabilidade , Biotransformação , Fenômenos Geológicos , Água Subterrânea/microbiologia , Microbiota , Compostos Orgânicos/análise , Compostos Orgânicos/química , Oxirredução , Microbiologia do Solo , Poluentes Químicos da Água/análise
8.
Food Chem ; 311: 125978, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31865114

RESUMO

The objective of this study was to investigate the effect of osmotic dehydration (with and without sonication) and the use of different types of edible coating on functional and color parameters of dried apricot. Osmotic pretreatment was carried out in sorbitol solution of 35 °Brix at 55 °C for 30 and 45 min. Two levels of ultrasound frequency (25 and 35 kHz) were tested. Samples were coated using pectin + citric acid (CA), pectin + ascorbic acid (AA) and pectin alone after osmotic treatment and were dried at 60 °C. The results revealed that ultrasound assisted osmotic dehydration (UOD) led to the loss of total phenolic compounds (TPC) and vitamin C compared to osmotic dehydration (OD). TPC and ß-carotene contents decreased with the increase in sonication frequency from 25 to 35 kHz. However, UOD pretreated samples showed higher antioxidant capacity and ß-carotene content than OD apricots. OD improved color of hot-air dried apricot compared to UOD pretreatment. The use of pectin + AA coating increased TPC and vitamin C retention and total antioxidant activity of OD or UOD pretreated samples compared to pectin or pectin + CA coatings. UOD and pectin + AA coated samples showed lower L* and b*, and higher a* values, whereas coating with CA improved color of dried apricot cubes. Coatings containing CA or AA promoted ß-carotene retention in dried apricot pretreated by OD and UOD.


Assuntos
Dessecação/métodos , Pectinas/química , Prunus armeniaca/metabolismo , Ácido Ascórbico/química , Ácido Cítrico/química , Cor , Fenóis/análise , Fenóis/metabolismo , Sonicação , Sorbitol/química , Espectrofotometria , beta Caroteno/análise , beta Caroteno/metabolismo
9.
Food Chem ; 306: 125625, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31606635

RESUMO

A novel ultrasonic-assisted vacuum drying technique for dehydrating garlic slices to give high quality products was developed. Garlic slices were dried at 60 °C using four methods: ultrasonic-assisted vacuum drying (USVD), vacuum drying (VD), ultrasonic-assisted drying (USD), and convective drying (CD, the control with no vacuum or ultrasonic applied). Drying kinetics, water-content changes, and properties of the garlic slices were assessed. Univariate linear and partial-least-squares regression models were used to predict the properties from low-field nuclear magnetic resonance parameters. USVD gave the shortest drying time (180 min less than CD) and provided a better garlic color and texture, and allicin retention rate than the other methods. Higher correlations between low-field nuclear magnetic resonance parameters and quality properties were found by partial-least-squares regression (PLSR) than by univariate analysis, with the analysis results being credible. Overall, ultrasonic-assisted vacuum drying produced high-quality products with its properties predicted well by low-field nuclear magnetic resonance.


Assuntos
Dessecação/métodos , Alho/química , Ultrassom , Cor , Cinética , Espectroscopia de Ressonância Magnética , Vácuo
10.
Chemosphere ; 238: 124628, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524606

RESUMO

This work investigated the improvement performances and mechanisms of waste activated sludge (WAS) dewaterability and the transformation behavior of heavy metals (HMs, including Cu, Zn, Pb, Cd and Cr) by jointly conditioning of Fe2+-activated peroxymonosulfate (PMS) oxidation and rice straw biochar (RS-BC). Experimental results showed that at original WAS pH of 6.5, the joint conditioning was the most effective when PMS dosage was 0.6 mmol·(g-volatile solids (VS))-1, Fe2+/PMS molar ratio was 0.6 and RS-BC dosage was 120 mg·(g-VS)-1. Under this condition, the lowest moisture content (MC) was 38.5% and the standardized-capillary suction time (SCST) was as high as 8.74. For the improvement mechanism, Fe2+-activated PMS oxidation can significantly disintegrate the extracellular polymeric substances (EPS) composing WAS to release EPS-bound water, and the RS-BC was helpful to form porous structures to improve WAS compressibility, facilitating the subsequent dewatering. In addition, Fe2+-activated PMS oxidation can obviously improve the solubilization and reduce the leaching toxicity of Cu, Zn, Pb, Cd and Cr, which was further enhanced by RS-BC. Therefore, the joint application of Fe2+-activated PMS oxidation and RS-BC can be a feasible way to improve WAS dewaterability and reduce HMs risk during WAS dewatering.


Assuntos
Carvão Vegetal/química , Metais Pesados/química , Oryza/química , Peróxidos/química , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Dessecação/métodos , Oxirredução
11.
Chemosphere ; 239: 124660, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31505445

RESUMO

The co-precipitation of Fe2+, Cu2+, Zn2+, Cd2+ and Ni2+ were investigated by a mechanochemical processing with CaCO3. The results showed that the synergies of the metal ions led to efficient co-precipitation. The precipitation of Fe2+, Cu2+ and Cd2+ are over 99% and that of Zn2+ and Ni2+ about 98.4% and 93.8%. A significant advantage of the process is that the moisture content of filter residue is much lower (less than 50%) than that using the lime neutralization (more than 80%), offering a potential solution to the sludge problem in wastewater treatment. A further advantage is the neutral pH (about 7.5) obtained by using CaCO3 rather than the highly alkaline pH (about 11) obtained using lime (Ca(OH)2) neutralization method.


Assuntos
Precipitação Fracionada/métodos , Metais Pesados/análise , Esgotos/química , Purificação da Água/métodos , Cádmio/análise , Carbonato de Cálcio/química , Cobre/análise , Dessecação/métodos , Concentração de Íons de Hidrogênio , Ferro/análise , Níquel/análise , Zinco/análise
12.
Food Chem ; 305: 125477, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610424

RESUMO

In recent years there is an increasing interest in dried fruits, although many of their nutritional components are readily lost during drying. The novelty of this paper was to assess the effect of hot-air drying (HAD) and far-infrared drying (FIRD) on the physicochemical properties and microstructure of mango slices pretreated with: control; 0.1% citric acid + 0.5% ascorbic acid + 0.5% CaCl2 + 1% NaCl; or 0.1% citric acid + 0.5% ascorbic acid + 0.5% CaCl2 + 1% NaCl + ultrasound treatments. Pretreatments resulted in a significant (p < 0.05) increase in reducing sugar, ascorbic acid and total phenol contents of dried samples. Moreover, compared with HAD, FIRD maintained a higher phenolic acid content, improved the nutrient retention and color attributes and better preserved microstructure. Therefore, pretreatments followed by FIRD is a potential method for obtaining high-quality dried mango slices.


Assuntos
Ácido Ascórbico/análise , Dessecação/métodos , Mangifera/química , Fenóis/análise , Ar , Cloreto de Cálcio/química , Cromatografia Líquida de Alta Pressão , Cor , Frutas/química , Frutas/metabolismo , Temperatura Alta , Raios Infravermelhos , Mangifera/metabolismo , Mangifera/ultraestrutura , Espectrometria de Massas , Sonicação
13.
J Sci Food Agric ; 100(1): 102-109, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31436308

RESUMO

BACKGROUND: The combination of sugar osmotic dehydration and microwave vacuum drying is an effective method for the dehydration of blackberries, the retention of their antioxidant properties, and the extension of their shelf life. Mass transfer during the osmotic dehydration of blackberries in sugar solution was investigated together with its influence on microwave vacuum drying characteristics, and the retention rate of anthocyanins in dried frozen blackberries. RESULTS: The concentrations of the osmotic solutions that were tested contained 40%, 50%, and 60% sugar, and the osmotic solution temperatures were 30 °C, 40 °C, and 50 °C. The solution-to-blackberry mass ratio was 10:1 (w/w) and the process duration varied from 0 to 5 h. A two-parameter mathematical model was used to describe mass transfer in the osmotic dehydration of blackberry samples and estimate moisture loss and solid gain in the final equilibrium. The results showed that the dehydration rate and solid gain rate of the blackberries increased with an increase in osmotic concentration, osmotic time, and the temperature of the solution under certain experimental conditions. The effective diffusivity of moisture and solute were estimated using the analytical solution of Fick's second law of diffusion. The moisture and effective diffusivities of sugar in the above osmotic dehydration conditions were in the range of 1.77 × 10-9 -2.10 × 10-9 and 1.36 × 10-9 -1.60 × 10-9 m2 .s-1 , respectively. CONCLUSION: The pretreatment of sugar osmosis greatly reduced the microwave vacuum drying time in the latter part of the dehydration period and increased anthocyanin retention. © 2019 Society of Chemical Industry.


Assuntos
Antocianinas/química , Dessecação/métodos , Manipulação de Alimentos/métodos , Rubus/química , Dessecação/instrumentação , Manipulação de Alimentos/instrumentação , Frutas/química , Micro-Ondas , Osmose , Temperatura , Vácuo , Água/análise
14.
Food Chem ; 309: 124935, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31732250

RESUMO

Cabbag has been considered as one of attractive raw materials for dehydrated vegetables owing to high nutrient value. However, information about how drying methods affect the physicochemical properties of cabbage is limited. In present study, segmented cabbages were subjected to freeze drying (FD), hot air drying (HAD), microwave vacuum drying (MVD), vacuum drying (VD), MVD combined with HAD (MVD + HAD) and VD (MVD + VD). Dehydrated cabbages were compared in terms of nutritional components, antioxidant activity, microstructure, texture and so on. Results demonstrated that HAD conducted a worse effect, with loss rate of nutritional components >45%. However, two combined methods performed higher retention for nutritional compositions, better antioxidant activity and lower energy consumption than individual HAD. Furthermore, MVD + HAD products exhibited higher rehydration capacity and more uniform honeycomb porous structure but lower hardness compared to HAD. This conclusion would be fundamental for choosing more appropriate drying methods to obtain desirable quality.


Assuntos
Antioxidantes/análise , Brassica/química , Dessecação/métodos , Liofilização , Temperatura Alta , Micro-Ondas , Vácuo
15.
Chemosphere ; 238: 124598, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31446276

RESUMO

Sewage sludge dewatering is an efficient approach to reduce the volume of sludge for the subsequent disposal. In this study, a novel one-step acidification sludge dewatering method was developed with using oxalic acid as a conditioner. In laboratory-scale experiments with the dosage of 200 mg/g dry solid (DS), the normalized capillary suction time and the specific resistance to filtration were respectively decreased by 78.7% and 60.0% after 30 min of oxalic acid conditioning, much more efficient than those conditioned with sulfuric acid and hydrochloric acid at the same pH value. This superior dewatering performance was attributed to two factors. One was that oxalic acid could more efficiently promote the hydrolysis of polysaccharide, especially pectins, to release bound water. The other was that OA could dissolve more Fe3+ and Al3+, as well as form precipitate with Ca2+ in sludge, which may act as flocculants or co-precipitator for the subsequent sludge particles coagulation. In pilot-scale experiments, the water content of oxalic acid conditioned sludge cake was reduced to 60% under the optimum conditions, while the reagent cost was as low as 110.0 USD/t DS. This work provides a cost-effective and easy-operated sewage sludge disposal technique, and also sheds light on the potential of oxalic acid in environmental waste treatment.


Assuntos
Dessecação/métodos , Ácido Oxálico/química , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Filtração , Floculação , Ácido Clorídrico/química , Concentração de Íons de Hidrogênio , Hidrólise , Polissacarídeos/metabolismo , Ácidos Sulfúricos/química , Água/química
16.
J Sci Food Agric ; 100(1): 354-361, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31588554

RESUMO

BACKGROUND: Postharvest processing, including drying, has a significant effect on the processability of oil crop seeds. High drying air temperature may significantly affect the levels of bioactive compounds in plant raw materials. We decided to investigate the subject given the lack of data on the drying of mustard seeds. The aim was to determine the effect of drying temperature on free fatty acid, phytosterol and tocopherol levels in the oil obtained from white mustard seeds. Seeds were dried in a thin layer at 40, 60, 80, 100, 120 and 140 °C. Changes in phytosterol levels were assessed using gas chromatography-mass spectrometry and changes in tocopherol levels by high-performance liquid chromatography. RESULTS: The analysis showed that, upon completion of air drying at 40-100 °C, losses of sterols did not exceed 5%, while upon completion of drying at 120 °C and 140 °C these losses amounted to 17-50%. Our investigation also showed that during drying of white mustard seed the total tocopherol levels increased, and the higher the drying temperature, the greater the increment. In seeds air-dried at 120 °C and 140 °C, the increase in tocopherol amounted to 7-9%. CONCLUSION: We also showed that the temperature of the drying agent significantly affects the tocopherol and phytosterol levels. It was found that a maximum temperature of 100 °C provides optimal drying conditions for mustard seeds. Principal component analysis identified two subgroups of oils obtained from seeds dried at 120 °C and 140 °C, which differed considerably from the other samples in terms of their bioactive component contents. © 2019 Society of Chemical Industry.


Assuntos
Dessecação/métodos , Fitosteróis/análise , Extratos Vegetais/análise , Sementes/química , Sinapis/química , Tocoferóis/análise , Cromatografia Gasosa-Espectrometria de Massas , Temperatura , Vitamina E/análise
17.
Pharm Res ; 37(1): 11, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31873825

RESUMO

PURPOSE: Loss of vaccine potency due to extreme temperature exposure during storage and transport remains a significant obstacle to the success of many vaccines, including the Bacille Calmette-Guérin (BCG) vaccine, the only vaccine available against Mycobacterium tuberculosis. BCG is a live, attenuated vaccine requiring refrigerated storage for viability. In this study, we formulated a temperature-stable BCG dry powder using the spray drying technique. METHODS: We employed a factorial design to optimize our formulation of stabilizing excipients that included L-leucine, bovine serum albumin, polyvinylpyrrolidone, mannitol, and trehalose. Powders were characterized for their particle size, yield, water retention and uptake, glass transition temperature, and aerosol performance. Three optimal powder carrier mixtures were selected from the factorial design for BCG incorporation based on their stability-promoting and powder flow characteristics. Vaccine powders were also assessed for BCG viability and in vivo immunogenicity after long-term storage. RESULTS: Live BCG was successfully spray-dried using the optimized carriers. Dry powder BCG showed no loss in viability (25°C, up to 60% relative humidity; RH) and ~2-log loss in viability (40°C, 75% RH) after one year of storage. The aerodynamic size of the powders was in the respirable range. Further, when healthy mice were immunized intradermally with reconstituted BCG powders (storage for 2 years), the vaccine retained its immunogenicity. CONCLUSION: We developed a spray-dried BCG vaccine that was viable and antigenic after long-term storage. To our knowledge, this is a first study to show room temperature stability of live BCG vaccine without any loss in viability for 12 months.


Assuntos
Vacina BCG/química , Vacina BCG/farmacologia , Composição de Medicamentos/métodos , Excipientes/química , Pós/química , Aerossóis/química , Animais , Linhagem Celular , Sobrevivência Celular , Dessecação/métodos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Feminino , Humanos , Leucina/química , Manitol/química , Camundongos Endogâmicos C57BL , Mycobacterium bovis/citologia , Povidona/química , Soroalbumina Bovina/química , Temperatura , Distribuição Tecidual , Trealose/química
18.
Pharm Res ; 37(1): 14, 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31873808

RESUMO

PURPOSE: The aim of this study is to determine the effects of saccharide-containing excipients on the surface composition of spray-dried protein formulations and their matrix heterogeneity. METHODS: Spray-dried formulations of myoglobin or bovine serum albumin (BSA) were prepared without excipient or with sucrose, trehalose, or dextrans. Samples were characterized by solid-state Fourier-transform infrared spectroscopy (ssFTIR), differential scanning calorimetry (DSC), size exclusion chromatography (SEC) and scanning electron microscopy (SEM). Protein surface coverage was determined by X-ray photoelectron spectroscopy (XPS), while conformational differences were determined by solid-state hydrogen/deuterium exchange with mass spectrometry (ssHDX-MS). RESULTS: Structural differences were exhibited with the inclusion of different excipients, with dextran formulations indicating perturbation of secondary structure. XPS indicated sucrose and trehalose reduced protein surface concentration better than dextran-containing formulations. Using ssHDX-MS, the amount of deuterium incorporation and populations present were the largest in the samples processed with dextrans. Linear correlation was found between protein surface coverage and ssHDX-MS peak area (R2 = 0.853) for all formulations with saccharide-containing excipients. CONCLUSIONS: Lower molecular weight species of saccharides tend to enrich the particle surface and reduce protein concentration at the air-liquid interface, resulting in reduced population heterogeneity and improved physical stability, as identified by ssHDX-MS.


Assuntos
Excipientes/química , Mioglobina/química , Soroalbumina Bovina/química , Química Farmacêutica/métodos , Dessecação/métodos , Deutério/química , Dextranos/química , Espectrometria de Massas/métodos , Sacarose/química , Propriedades de Superfície , Trealose/química
19.
AAPS PharmSciTech ; 20(8): 328, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673810

RESUMO

This work presents a new user-friendly lyophilization simulation and process optimization tool, freely available under the name LyoPRONTO. This tool comprises freezing and primary drying calculators, a design-space generator, and a primary drying optimizer. The freezing calculator performs 0D lumped capacitance modeling to predict the product temperature variation with time which shows reasonably good agreement with experimental measurements. The primary drying calculator performs 1D heat and mass transfer analysis in a vial and predicts the drying time with an average deviation of 3% from experiments. The calculator is also extended to generate a design space over a range of chamber pressures and shelf temperatures to predict the most optimal setpoints for operation. This optimal setpoint varies with time due to the continuously varying product resistance and is taken into account by the optimizer which provides varying chamber pressure and shelf temperature profiles as a function of time to minimize the primary drying time and thereby, the operational cost. The optimization results in 62% faster primary drying for 5% mannitol and 50% faster primary drying for 5% sucrose solutions when compared with typical cycle conditions. This optimization paves the way for the design of the next generation of lyophilizers which when coupled with accurate sensor networks and control systems can result in self-driving freeze dryers.


Assuntos
Química Farmacêutica/métodos , Manitol/síntese química , Sacarose/síntese química , Dessecação/métodos , Liofilização/métodos , Congelamento , Temperatura Alta , Temperatura
20.
Isotopes Environ Health Stud ; 55(6): 526-531, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31597451

RESUMO

Drying protocols might alter the isotopic signatures of plant samples given that high temperatures can volatilize various organic compounds or delay the halting of physiological processes at lower drying temperatures. We thus evaluated the effect of four drying protocols on the carbon and nitrogen isotopic signatures for 23 species of plants. In particular, leaves were either freeze-dried, placed in a herbarium drying stove (ca. 50°C), in a gravity convection oven (80°C), or microwaved (900 W) in 2-minute pulses, until constant weight. For each species, neither treatment led to significantly different δ13C values, which ranged from -31.7 to -12.4‰. The δ15N values of 21 of the species considered were not affected by the drying protocols, ranging from -11.6 to -8.8‰. For Tillandsia makoyana, significant differences were observed between the freeze dried and the microwaved samples and between the freeze dried samples and those dried at 50°C for Macroptilium gibbosifolium.


Assuntos
Isótopos de Carbono/análise , Dessecação/métodos , Monitoramento Ambiental/métodos , Liofilização , Isótopos de Nitrogênio/análise , Folhas de Planta/química , Fabaceae/química , Temperatura Alta , Inquéritos e Questionários , Volatilização
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