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1.
Planta Med ; 83(10): 870-876, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28196382

RESUMEN

An ideal wound dressing ensures a moist environment around the wound area and absorbs exudates from the wound surface. Topical application of bromelain to incised wounds has been shown to reprogram the wound microenvironment to promote effective tissue repair. Combining the characteristics of hydrogels and bromelain is therefore of great interest. Herein, we describe the development of a hydrogel, formulated using alginate and Arabic gum, for bromelain loading and release. The hydrogel formulation was evaluated using response surface methodology, considering the pH value and the concentration of alginate and Arabic gum. Bromelain loading and release were evaluated based on passive diffusion. Differential scanning calorimetry and Fourier transform infrared spectroscopy were performed to confirm bromelain immobilization in the hydrogel. The final hydrogel formulation had a swelling ratio of 227 % and incorporated 19 % of bromelain from a bromelain solution. Bromelain immobilization in the hydrogel was the result of hydrogen bond formation and was optimal at 4 °C after 4 h of contact. This evidence suggests that bromelain entrapment into a hydrogel is a promising strategy for the development of wound dressings that support the debridement of burns and wounds.


Asunto(s)
Alginatos , Bromelaínas/administración & dosificación , Liberación de Fármacos , Goma Arábiga , Bromelaínas/metabolismo , Composición de Medicamentos , Ácido Glucurónico , Ácidos Hexurónicos , Hidrogel de Polietilenoglicol-Dimetacrilato
2.
Pharm Dev Technol ; 17(4): 429-36, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21222512

RESUMEN

Polymer film based on pH-dependent Eudragit FS 30 D acrylic polymer in association with arabinoxylane, a polysaccharide issued from gum psyllium, was produced by way of solvent casting. Physical-chemical characterization of the polymer film samples was performed by means of thermogravimetry (TGA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Furthermore, water-equilibrium swelling index (I(s)) and weight loss of the films in KCl buffer solution of pH 1.2, in KH(2)PO(4) buffer solution of pH 5.0, or in KH(2)PO(4) buffer solution of pH 5.0 consisting of 4% enzyme Pectinex 3X-L (w/v) were also carried out for the film characterization. No chemical interactions between the Eudragit FS 30 D and the arabinoxylane polymer chains were evidenced, thus suggesting that the film-forming polymer structure was obtained from a physical mixture of both polymers. The arabinoxylane-loader films showed a more pronounced weight loss after their immersion in buffer solution containing enzyme Pectinex 3X-L. The introduction of the arabinoxylane makes the film more susceptible to undergo an enzymatic degradation. This meant that the enzyme-dependent propriety issued from the arabinoxylane has been imprinted into the film formulation. This type of polymer film is an interesting system for applications in colon-specific drug delivery system.


Asunto(s)
Colon/metabolismo , Sistemas de Liberación de Medicamentos , Ácidos Polimetacrílicos/química , Psyllium/química , Xilanos/química , Rastreo Diferencial de Calorimetría , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Hidrolasas/metabolismo , Ácidos Polimetacrílicos/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Xilanos/metabolismo
3.
Nat Prod Res ; 36(17): 4475-4481, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34618614

RESUMEN

Baru nuts (Dipteryx alata Vog.) are a native species from Brazil, rich in phenols and other antioxidants, with high socioeconomic value and possible pharmaceutical applications. Here we investigated baru nut ethanolic extract (BNEE) antioxidant and wound healing activities in human NCI-H441 and A549 lung epithelial cell lines for a possible use in conditions related to oxidative stress and wound healing impairments, such as chronic obstructive pulmonary disease (COPD). BNEE was characterised with high DPPH free radical scavenging activity and high total phenolics content, amongst them gallic acid, that was identified and quantified by HPLC. BNEE was not cytotoxic at concentrations studied, reduced the levels of reactive oxygen species before and during oxidative stress and increased wound healing in cell monolayers. These are the first steps to investigate the beneficial properties of baru in diseases related to oxidative stress and wound healing impairments such as COPD.


Asunto(s)
Dipteryx , Enfermedad Pulmonar Obstructiva Crónica , Antioxidantes/análisis , Antioxidantes/farmacología , Dipteryx/química , Células Epiteliales , Humanos , Pulmón , Nueces/química , Fenoles/análisis , Fenoles/farmacología , Extractos Vegetales/análisis , Extractos Vegetales/farmacología , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Cicatrización de Heridas
4.
Environ Technol ; 42(23): 3675-3687, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32148175

RESUMEN

This paper presents the photocatalysis, adsorption, and photolysis of C.I. Reactive Blue 21 dye using synthesized zinc oxide nanoparticles. The density, mean particle diameter, surface area, and porosity of the catalyst were 5550 kg/m3, 1.19 × 10-7, 16,830 m2/kg, and 0.08, respectively. The impact of catalyst mass per volume of solution (0.2-1.0 kg/m3) was experimentally investigated in terms of the percentage of dye degradation. Due to the small catalyst porosity, adsorption contributed little to overall degradation. However, the photolysis of the dye was around 12.5%, which occurred predominantly between 0 and 5 min. In the second part of the present study, the photocatalytic degradation of C.I. Reactive Blue 21 was modelled mathematically based on the mass conservation law in the solution and catalyst. The model had two adjustable variables: the convection mass transfer coefficient and the photocatalytic reaction rate constant. The model was solved numerically using the finite difference method and was validated with the experimental data. The validated model was employed to examine the impact of catalyst size and initial pollutant concentration on the photocatalytic degradation.


Asunto(s)
Nanopartículas , Óxido de Zinc , Catálisis , Metaloporfirinas , Fotólisis
5.
Air Qual Atmos Health ; 14(12): 2091-2099, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34745381

RESUMEN

This work aims to obtain an artificial neural network to simulate hospitalizations for respiratory diseases influenced by pollutant gaseous such as CO, PM10, PM2.5, NO2, O3, and SO2 emitted from 2011 to 2017, in the city of São Paulo. The hospitalization costs were also be calculated. MLP and RBF neural networks have been tested by varying the number of neurons in the hidden layer and the type of equation of the output function. The following pollutants and its concentration range were collected considering the supervision of Alto Tiete station set, in several neighborhoods in the city of São Paulo, from in the period 2011 to 2017: 28-63 µg/m3 of PM2.5, 52-110 µg/m3 of PM10, 49-135 µg/m3 of O3, 0.8-2.6 ppm CO, 41-98 µg/m3 of NO2, and 3-16 µg/m3 of SO2. Results showed that a RBF neural network with 6 input neurons, 13 hidden layer neurons, and 1 output neuron, using BFGS algorithm and a Gaussian function to neuronal activation, was the best fitted to the experimental datasets. So, knowing the monthly concentration of gaseous pollutions was possible to predict the hospitalization of 1464 to 3483 ± 510 patients, with costs between 570,447 and 1,357,151 ± 198,171 USD per month. This way, it is possible to use this neural network to predict the costs of hospitalizing patients for respiratory diseases and to contribute to the decision-making of how much the government should spend on health care.

6.
J Chromatogr B Analyt Technol Biomed Life Sci ; 877(5-6): 521-6, 2009 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-19162572

RESUMEN

An extracellular lipase was isolated from Pseudomona cepacia by expanded bed adsorption on an Amberlite 410 ion-exchange resin. Enzyme characterization and hydrodynamic study of a chromatography column were done. Enzyme purification was done at three condition of expanded bed height (H): at one and half (6cm), at two (8cm) and at three (12cm) times the fixed bed height (H(0)=4cm). The results showed that the experimental data was fitted to the Richardson and Zaki equation, and the comparison between the experimental and calculated terminal velocities showed low relative error. In enzyme purification for better condition, a purification factor of about 80 times was found at 6cm of expanded bed height, or 1.5 times of expansion degree. Purified lipase had an optimal pH and a temperature of 8 and 37 degrees C, respectively.


Asunto(s)
Álcalis/química , Burkholderia cepacia/enzimología , Lipasa/aislamiento & purificación , Adsorción , Proteínas Bacterianas/análisis , Tampones (Química) , Concentración de Iones de Hidrógeno , Hidrólisis , Resinas de Intercambio Iónico/química , Aceite de Oliva , Aceites de Plantas , Temperatura
7.
Polymers (Basel) ; 11(10)2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31618858

RESUMEN

Bromelain, a set of proteolytic enzymes potential pharmaceutical applications, was encapsulated in chitosan nanoparticles to enhance enzyme stability, and the effect of different chitosan sources was evaluated. Chitosan types (i.e., low molecular weight chitosan, chitosan oligosaccharide lactate, and chitosan from shrimp shells) produced nanoparticles with different physicochemical properties, however in all cases, particle size and zeta potential decreased, and polydispersity index increased after bromelain addition. Bromelain encapsulation was higher than 84% and 79% for protein content and enzymatic activity, respectively, with low molecular weight chitosan presenting the highest encapsulation efficiency. Nanoparticle suspension was also tested for accelerated stability and rheological behavior. For the chitosan-bromelain nanoparticles, an instability index below 0.3 was recorded and, in general, the loading of bromelain in chitosan nanoparticles decreased the cohesiveness of the final suspension.

8.
Data Brief ; 18: 1224-1228, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29900298

RESUMEN

The data presented in this article are related to the research article "Environmental and techno-economic considerations on biodiesel production from waste frying oil in São Paulo city" (Silva Filho et al., 2018) [1]. This article presents the variation of the concentration of waste frying oil (WFO) with the reaction time and temperature during the transesterification of WTOs collected in the residences and restaurants of the city of São Paulo. Then, the biodiesel samples were mixed with the S-10 diesel oil in order to obtain the B10, B20, B30, B40, B50, B75 and B100 blends, which were tested in a diesel engine and their power, fuel consumption and gas emissions (CO, CO2 and SO2) have been measured to verify their greenhouse effect and energy efficiency.

9.
J AOAC Int ; 101(5): 1461-1465, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29895343

RESUMEN

BACKGROUND: The fruits acerola and red plum are known to be good sources of antioxidants, particularly vitamin C. Antioxidants are compounds that protect organisms from biomolecular damage, such as accelerated aging, caused by free radicals. OBJECTIVE: The objective of this study was to extract vitamin C from acerola and red plum, incorporate these extracts into different topical formulations, and evaluate the physicochemical stabilities of these formulations under stress conditions. METHODS: Vitamin C was extracted from acerola and red plum via dynamic maceration for 2 h at 50 ± 2°C and was quantified via HPLC. In vitro antioxidant activities were evaluated using DPPH assays. The extracts were then incorporated into emulsion and gel formulations in two types of packaging, and stability studies were carried out. RESULTS: Red plum and acerola extracts were orange and red and contained vitamin C concentrations of 2732.70 ± 93.01 mg/100 g and 2.60 ± 1.2 mg/100 g, respectively. In vitro antioxidant activity resulted in over 90.0% inhibition of free radicals at 0.01 mL/mL acerola extract and 0.1 mL/mL red plum extract. In the stability study, pH values decreased for both acerola formulations when stored in the oven or in transparent glass containers. Formulations containing red plum extract were stable under all conditions. Acerola extracts contained a higher concentration of vitamin C than red plum extracts. Both extracts possessed antioxidant activity, although the acerola-based formulation was unstable when stored at high temperatures or in transparent glass containers. HIGHLIGHTS: Extracts from red plum and acerola contained vitamin C; antioxidant activity of the extracts resulted in over 90.0% inhibition of free radicals. Formulations containing red plum were stable under all tested conditions, and formulations containing acerola were unstable when stored in the oven or in transparent glass containers.


Asunto(s)
Antioxidantes/análisis , Ácido Ascórbico/análisis , Cromatografía Líquida de Alta Presión/métodos , Malpighiaceae/química , Extractos Vegetales/análisis , Prunus domestica/química , Administración Tópica , Antioxidantes/administración & dosificación , Antioxidantes/farmacología , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/farmacología , Composición de Medicamentos , Estabilidad de Medicamentos , Emulsiones/química , Radicales Libres/química , Frutas/química , Geles/química , Vehículos Farmacéuticos/química , Extractos Vegetales/administración & dosificación , Extractos Vegetales/farmacología
10.
Braz. J. Pharm. Sci. (Online) ; 58: e191042, 2022. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1394057

RESUMEN

Abstract L-Asparaginase (L-ASNase) is a biopharmaceutical used for acute lymphoblastic leukaemia (ALL) treatment, dramatically increasing the patients' chance of cure. However, its production and distribution in developing countries were disrupted because of its low profitability, which caused great concern among patients. This study evaluates the feasibility of combining fractional precipitation and aqueous two-phase systems (ATPS) to purify L-ASNase from a low-grade product, commercially known as Acrylaway® L. The ATPS purification results were not particularly expressive compared to the two-step purification process composed of ethanol precipitation and gel filtration, which was able to recover the target molecule with a purification factor over 5 fold. Thus, we studied a purification process capable of manufacturing pharmaceutical grade L-ASNase from a commercially available low-grade raw material; however, improvements regarding its throughput must be achieved, and high purity is the first step to apply it as a new biopharmaceutical product. The proposed process could pose as a short-time solution to mitigate its shortage while a cost-effective production plant is being developed.


Asunto(s)
Asparaginasa/aislamiento & purificación , Precipitación Fraccionada/métodos , Antineoplásicos/aislamiento & purificación , Estudios de Factibilidad , Cromatografía en Gel , Análisis Costo-Beneficio
11.
Biomed Res Int ; 2016: 8409183, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26925415

RESUMEN

Given the importance of protease's worldwide market, the determination of optimum conditions and the development of a standard protocol are critical during selection of a reliable method to determine its bioactivity. This paper uses quality control theory to validate a modified version of a method proposed by Charney and Tomarelli in 1947. The results obtained showed that using azocasein substrate bromelain had its optimum at 45°C and pH 9 (Glycine-NaOH 100 mM). We also quantified the limit of detection (LoD) and limit of quantification (LoQ) in the above-mentioned optimum (0.072 and 0.494 mg·mL(-1) of azocasein, resp.) and a calibration curve that correlates optical density with the amount of substrate digested. In all analysed samples, we observed a significant decrease in response after storage (around 17%), which suggests its use must be immediately after preparation. Thus, the protocol presented in this paper offers a significant improvement, given that subjective definitions are commonly used in the literature and this simple mathematical approach makes it clear and concise.


Asunto(s)
Bromelaínas/química , Caseínas/química , Proteolisis/efectos de los fármacos , Bromelaínas/farmacología , Caseínas/farmacología , Concentración de Iones de Hidrógeno , Límite de Detección , Especificidad por Sustrato
12.
Biotechnol Prog ; 31(4): 937-45, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25919128

RESUMEN

Bromelain is a set of proteolytic enzymes found in pineapple (Ananas comosus) tissues such as stem, fruit and leaves. Because of its proteolytic activity, bromelain has potential applications in the cosmetic, pharmaceutical, and food industries. The present study focused on the recovery of bromelain from pineapple peel by liquid-liquid extraction in aqueous two-phase micellar systems (ATPMS), using Triton X-114 (TX-114) and McIlvaine buffer, in the absence and presence of electrolytes CaCl2 and KI; the cloud points of the generated extraction systems were studied by plotting binodal curves. Based on the cloud points, three temperatures were selected for extraction: 30, 33, and 36°C for systems in the absence of salts; 40, 43, and 46°C in the presence of KI; 24, 27, and 30°C in the presence of CaCl2 . Total protein and enzymatic activities were analyzed to monitor bromelain. Employing the ATPMS chosen for extraction (0.5 M KI with 3% TX-114, at pH 6.0, at 40°C), the bromelain extract stability was assessed after incorporation into three cosmetic bases: an anhydrous gel, a cream, and a cream-gel formulation. The cream-gel formulation presented as the most appropriate base to convey bromelain, and its optimal storage conditions were found to be 4.0 ± 0.5°C. The selected ATPMS enabled the extraction of a biomolecule with high added value from waste lined-up in a cosmetic formulation, allowing for exploration of further cosmetic potential.


Asunto(s)
Ananas/enzimología , Bromelaínas/química , Bromelaínas/aislamiento & purificación , Fraccionamiento Químico/métodos , Cosméticos/química , Micelas , Biotecnología
13.
Artículo en Inglés | MEDLINE | ID: mdl-15177161

RESUMEN

Bromelain is an enzymatic complex obtained from pineapple (Ananas comosus) fruits and stem. Thermoseparation of bromelain by poly(ethylene oxide) (PEO)- poly(propylene oxide) (PPO)- poly(ethylene oxide) (PEO) block copolymers aqueous solutions was studied. Triblock copolymers with different EO percentages and different molecular mass were evaluated. Copolymer solutions at different pH values, buffer concentrations and copolymer concentrations were investigated. It was found that cloud point temperature increases as a function of %EO and decreases with copolymer molecular mass, copolymer concentration and buffer concentration. The results showed that all the studied factors influenced enzyme partition. The best conditions were copolymer with 10% EO and molecular mass of 2000 g/mol, temperature of 25 degrees C, copolymer concentration of 5% (w/w), pH 6.0 and salt concentration of 15 mM. Enzyme activity recovery around 79.5%, purification factor around 1.25 and activity partition coefficient around 1.4 were obtained.


Asunto(s)
Bromelaínas/aislamiento & purificación , Polietilenglicoles/química , Polímeros/química , Polipropilenos/química , Concentración de Iones de Hidrógeno , Peso Molecular , Temperatura
14.
Braz. arch. biol. technol ; 62: e19180343, 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1011533

RESUMEN

Abstract Microalgae are aquatic unicellular microorganisms that can be found both in freshwater and marine systems; are capable of photosynthesis; and can grow as individual cells or associated in chains or small colonies. Microalgae cultivation has gained large momentum among researchers in the past decades due to their ability to produce value metabolites, remarkable photosynthetic efficiency, and versatile nature. The wide technological potential, and thus increasing amount of scattered knowledge, may become the very first barrier that a post graduating student, or any non-specialist reader, will face when introduced to the subject. In this review paper, we access the core aspects of microalgae technology, covering their main characteristics, and comprehensively presenting the main features of their various cultivation modes and biological activity from metabolites.


Asunto(s)
Producción de Cultivos , Microalgas/crecimiento & desarrollo , Fitoquímicos , Proteínas del Complejo del Centro de Reacción Fotosintética
15.
Braz. arch. biol. technol ; 56(6): 971-979, Nov.-Dec. 2013. ilus, tab
Artículo en Inglés | LILACS | ID: lil-696944

RESUMEN

The aim of this work was to isolate and purify bromelain extracted from the pineapple peel by ammonium sulfate precipitation (40-80%), followed by desalting and freeze-drying with a 75% activity recovery and 2.2 fold increased specific activity. Ion exchange chromatography on DEAE-Sepharose was able to separate the polysaccharides from the enzyme, which was recovered in the elution step, maintaining its enzymatic activity. The batch adsorption of bromelain was evaluated in terms of total protein and enzymatic activity using Langmuir and Langmuir-Freundlich models. Results showed that the process could be suitable for the recovery and purification of the enzyme, maintaining its specific activity.

16.
Braz. arch. biol. technol ; 55(1): 7-19, Jan.-Feb. 2012. ilus, tab
Artículo en Inglés | LILACS | ID: lil-622676

RESUMEN

This work aimed to study the partitioning of a lipase produced by Burkholderia cepacia in PEG/Phosphate aqueous two phase system (ATPS) and its characterization. Lipase was produced by B. cepacia strains in a fermenter. Enzyme partitioning occurred at pH 6.0 and 8.0, using PEG 1500 and 6000 on two tie lines. Metal ions, pH and temperature effects on enzyme activity were evaluated. Five milliliter of 7.5% olive oil emulsion with 2.5% gumarabic in 0.1M sodium phosphate buffer at pH 8.0 and 37ºC were used for the activity determinations. Results showed that crude stratum from B. cepacia was partitioned by PEG1500/phosphate ATPS at pH 6.0 or 8.0 for, which the partitioning coefficients were 108-and 209-folds. Lipase presented optimal activity conditions at 37ºC and pH 8.0; it showed pH-stability for 4 h of incubation at different pH values at 37ºC. Metal ions such as Mn2+ , Co2+, I-and Ca2+ sustained enzymatic activities; however, it was inhibited by the presence of Fe2+, Hg2+ and Al3+ . Km and Vmax values were 0.258 U/mg and 43.90 g/L, respectively. A molecular weight of 33 kDa and an isoelectric point at pH 5.0 were determined by SDS-PAGE and IFS electrophoresis, respectively.

17.
Braz. arch. biol. technol ; 55(3): 465-470, May-June 2012. ilus, tab
Artículo en Inglés | LILACS | ID: lil-640198

RESUMEN

The aim of this work was to study the production of e bromelain from the Ananas comosus L. Merril, by determining the process conditions using flat membranes. The production system modeling generated a hyperbolical curve and the optimization by response surfaces showed an influence of the transmembrane pressure higher than the pH influence. The cost of the production of bromelain from A. comosus was estimated 9 to 13 times lower than Sigma's retail sales price and 6.5 to 8.5 times lower than when this enzyme was obtained through a liquid-liquid extraction, which showed the economical feasibility of the process.

18.
Braz. arch. biol. technol ; 55(5): 647-652, Sept.-Oct. 2012. ilus, tab
Artículo en Inglés | LILACS | ID: lil-651646

RESUMEN

This study aimed to obtain the condition of maximum bromalein activity in different parts of pineapple plants produced in vitro, by micropropagation. The sStems and leaves of Pérola and Imperial cultivar plants were evaluated after three and eight months of in vitro cultivation in Murashige and Skoog medium without growth phytoregulator, macerated in potassium phosphate buffer at different pH values (5.7, 6.7 and 7.7). Total protein and proteolytic activity were determined in the samples after three- and eight-month cultivation periods. For both the cultivars, the best results were obtained at pH 5.7 in extraction media. Pérola cultivar, showed higher bromelain activity in the leaves cultivated in vitro for three months (0.0194U/mL) while in the Imperial cultivar, it was higher in the stem after eight months (0.0179 U/mL). Imperial cultivar showed higher bromelain activity than the Pérola's.

19.
Braz. arch. biol. technol ; 54(1): 125-132, Jan.-Feb. 2011. ilus, graf, tab
Artículo en Inglés | LILACS | ID: lil-576768

RESUMEN

In this work, the thermodynamic equilibrium and applying of PEG4000/Phosphate ATPS on the purification of bromelain extracted from pineapple was studied. A rigorous study of the equilibrium curves and tie-line length from PEG4000/phosphate ATPS were done for the pH 6-11 at 25ºC. Results showed that there was augment in the PEG and salt contents with the high pH value from PEG4000/Phosphate ATPS and two-phase formation needed only increasing the PEG content. Two tie-line length at pH 11 from PEG4000/Phosphate ATPS were optimal condition for bromelain purification, one on composition of 14 percent PEG and 13 percent salt and other at 12.6 percent PEG and 12.2 percent salt, while a 25-62 folds of enzyme was found. SDS-PAGE electrophoreses had one band only, which showed that bromelain was purified. Optimum conditions of bromelain use were found at pH 7 and between 30-40ºC.

20.
Braz. arch. biol. technol ; 53(2): 455-463, Mar.-Apr. 2010. ilus, tab
Artículo en Inglés | LILACS | ID: lil-546578

RESUMEN

A pulsed-cap microcolumn was used for bromelain extraction from pineapple juice by reversed micelles. The cationic micellar solution used BDBAC as the surfactant, isooctane as the solvent and hexanol as the co-solvent. In order to capture the dynamic behavior and the nonlinearities of the column, the operating conditions were modified in accordance with the central composite design for the experiment, using the ratio between the light phase flow rate and the total flow rate, and the time interval between pulses. The effects on the purification factor and on total protein yield were modeled via neural networks. The best topology was defined as 16-9-2, and the input layer was a moving window of the independent variables. The neural model successfully predicted both the purification factor and the total protein yield from historical data. At the optimal operating point, a purification factor of 4.96 and a productivity of 1.29 mL/min were obtained.


Uma micro-coluna com campânulas pulsantes foi utilizada para a extração de bromelina a partir de suco de abacaxi, usando micelas reversas. A solução catiônica micelar foi composta do surfactante BDBAC, do solvente iso-octano e do co-solvente hexanol. Seguindo um planejamento experimental, perturbações foram impostas à coluna de extração com o objetivo de capturar seu comportamento dinâmico e suas não-linearidades, usando a razão entre a vazão da fase leve e vazão total, e o intervalo de tempo entre os pulsos. Os efeitos das variáveis independentes sobre o fator de purificação e sobre o rendimento em proteínas totais foram modelados via redes neurais artificiais. A melhor topologia de rede obtida foi definida como 16-9-2, usando um esquema de janela móvel no tempo das variáveis independentes. O modelo neural obtido do histórico do processo se mostrou adequado para predizer simultaneamente o fator de purificação e o rendimento do processo em proteínas totais. No ponto ótimo de operação, foi encontrado um fator de purificação de 4.96, com produtividade de 1.29 mL/min.

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