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1.
Eur J Nutr ; 57(5): 1793-1805, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28526925

RESUMO

PURPOSE: Phenolic compounds (PC) of virgin olive oil exert several biochemical and pharmacological beneficial effects. Some dietary PC seem to prevent/improve obesity and metabolic-related disorders such as non-alcoholic fatty liver disease (NAFLD). We investigated the possible effects of PC extracted from olive pomace (PEOP) and of the main single molecules present in the extract (tyrosol, apigenin, oleuropein, p-coumaric and caffeic acid) in protecting hepatocytes and endothelial cells against triglyceride accumulation and oxidative stress. METHODS: Rat hepatoma and human endothelial cells were exposed to a mixture of oleate/palmitate to mimic the condition of NAFLD and atherosclerosis, respectively. Then, cells were incubated for 24 h in the absence or in the presence of PC or PEOP. Different parameters were evaluated, such as lipid accumulation and oxidative stress-related markers. RESULTS: In hepatic cells, expression of peroxisome proliferator-activated receptors (PPARs) and of stearoyl-CoA desaturase 1 (SCD-1) were assessed as index of lipid metabolism. In endothelial cells, expression of intercellular adhesion molecule-1 (ICAM-1), activation of nuclear factor kappa-B (NF-kB), release of nitric oxide (NO), and wound-healing rate were assessed as index of inflammation. CONCLUSION: PEOP extract ameliorated hepatic lipid accumulation and lipid-dependent oxidative imbalance thus showing potential applications as therapeutic agent tuning down hepatosteatosis and atherosclerosis.


Assuntos
Células Endoteliais/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polifenóis/farmacologia , Animais , Linhagem Celular Tumoral , Células Cultivadas , Células Endoteliais/metabolismo , Ácidos Graxos/efeitos adversos , Ácidos Graxos/metabolismo , Hepatócitos/metabolismo , Humanos , Metabolismo dos Lipídeos , Fígado , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ratos
2.
J Microencapsul ; 34(2): 111-120, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28288552

RESUMO

The cocoa extract (Theobroma cacao L.) has a significant amount of polyphenols (TP) with potent antioxidant activity (AA). This study aims to optimise microencapsulation of the extract of cocoa waste using chitosan and maltodextrin. Microencapsulation tests were performed according to a Box-Behnken factorial design, and the results were evaluated by response surface methodology with temperature, maltodextrin concentration (MD) and extract flowrate (EF) as independent variables, and the fraction of encapsulated TP, TP encapsulation yield, AA, yield of drying and solubility index as responses. The optimum conditions were: inlet temperature of 170 °C, MD of 5% and EF of 2.5 mL/min. HPLC analysis identified epicatechin as the major component of both the extract and microparticles. TP release was faster at pH 3.5 than in water. These results as a whole suggest that microencapsulation was successful and the final product can be used as a nutrient source for aquatic animal feed. Highlights Microencapsulation is optimised according to a factorial design of the Box-Behnken type. Epicatechin is the major component of both the extract and microcapsules. The release of polyphenols from microcapsules is faster at pH 3.5 than in water.


Assuntos
Cacau , Quitosana/química , Composição de Medicamentos , Polifenóis/química , Polissacarídeos/química , Ração Animal , Cápsulas , Temperatura
3.
Mar Drugs ; 14(11)2016 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-27879659

RESUMO

Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including ß-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.


Assuntos
Biotecnologia/métodos , Carotenoides/química , Microalgas/química , Alga Marinha/química , Cromatografia com Fluido Supercrítico/métodos , Humanos , Micro-Ondas , Solventes/química
4.
Food Technol Biotechnol ; 53(2): 207-214, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27904350

RESUMO

The adsorption of phenolic compounds from olive oil wastewater by commercial activated carbon was studied as a function of adsorbent quantity and temperature. The sorption kinetics and the equilibrium isotherms were evaluated. Under optimum conditions (8 g of activated carbon per 100 mL), the maximum sorption capacity of activated carbon expressed as mg of caffeic acid equivalent per g of activated carbon was 35.8 at 10 °C, 35.4 at 25 °C and 36.1 at 40 °C. The pseudo-second-order model was considered as the most suitable for kinetic results, and Langmuir isotherm was chosen to better describe the sorption system. The results confirmed the efficiency of activated carbon to remove almost all phenolic compound fractions from olive mill effluent. The preliminary results obtained will be used in future studies. The carbohydrate fraction of this upgraded residue could be employed to produce bioethanol, and adsorbed phenolic compounds can be recovered and used in different industries.

5.
ScientificWorldJournal ; 2014: 961437, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25610914

RESUMO

The influence of titanium dioxide nanoparticles (pure anatase and 15% N doped anatase) on the growth of Chlorella vulgaris, Haematococcus pluvialis, and Arthrospira platensis was investigated. Results showed that pure anatase can lead to a significant growth inhibition of C. vulgaris and A. platensis (17.0 and 74.1%, resp.), while for H. pluvialis the nanoparticles do not cause a significant inhibition. Since in these stress conditions photosynthetic microorganisms can produce antioxidant compounds in order to prevent cell damages, we evaluated the polyphenols content either inside the cells or released in the medium. Although results did not show a significant difference in C. vulgaris, the phenolic concentrations of two other microorganisms were statistically affected by the presence of titanium dioxide. In particular, 15% N doped anatase resulted in a higher production of extracellular antioxidant compounds, reaching the concentration of 65.2 and 68.0 mg gDB (-1) for H. pluvialis and A. platensis, respectively.


Assuntos
Proliferação de Células , Clorófitas/efeitos dos fármacos , Nanopartículas/química , Polifenóis/metabolismo , Titânio/farmacologia , Clorófitas/metabolismo , Clorófitas/fisiologia , Fotossíntese , Spirulina/efeitos dos fármacos , Spirulina/metabolismo , Spirulina/fisiologia
6.
Foods ; 13(5)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38472755

RESUMO

Radio frequency identification (RFID) technology is crucial in revolutionizing the food supply chain and combating global food waste. However, this technology faces challenges in full integration due to disruptive effects on tags caused by the dielectric properties of food and beverage ingredients, chemical constituents, and their packaging. This paper aims to demonstrate the effect of packaging and beverage contents on RFID tag performance. Three commercially available ultra-high frequency (UHF) RFID tags with different designs were tested on polyethylene terephthalate (PET) bottles, measuring tag performance through sensitivity, backscatter, and read range in the presence of various water-based solutions and commercially available beverages. The results highlight the substantial impact of the beverage type and tag design on RFID performance. The results of this study showed that tag 3 was the most consistent and readable tag amongst those tested in the presence of different beverage contents. Tag 3 resulted in a sensitivity ranging from -0.49 to -2.01 dBm, backscatter from -38.16 to 43.59 dBm, and read range from 1.58 to 1.88 m, while tag 1 performed the best in the presence of an empty PET bottle resulting in a sensitivity of -20.78 dBm, backscatter of -23.65 dBm, and read range of 16.34 m. The results of this study can be used for further investigations to develop a mathematical model that predicts the RFID tag performance based on the food composition. This model will be helpful for the design of the tags while facilitating the adoption of smart packaging for food traceability.

7.
Foods ; 12(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37893640

RESUMO

Industrial processing of tart cherries (Prunus cerasus L.) produces bioproducts like cherry pits (CP), which contribute to adverse environmental effects. To identify sustainable strategies to minimize the environmental impact of cherry processing, we investigated their potential value as antioxidants for prospective utilization within cosmeceutical applications. Untargeted metabolomic analyses of water and water: ethanol CP extracts using an eco-friendly technique revealed significant enrichment in coumaroyl derivatives and flavonoids with congruent metabolite representation regardless of the extraction solvent. The antioxidant activity of tart CP extracts was evaluated on human skin cells exposed to H2O2 or LPS, modeling environmentally induced oxidants. Notably, both CP extracts provide antioxidant activity by reducing H2O2 or LPS-induced ROS in human skin keratinocytes without affecting cell viability. The CP extracts increased the expression of CAT and SOD1 genes encoding antioxidant regulatory enzymes while decreasing the expression of NOS2, a pro-oxidant regulator. These findings reveal the antioxidant properties of tart CP, offering new opportunities to produce natural-based skin care products and adding economic value while providing sustainable options to reduce the environmental impact of food byproducts.

8.
J Biomed Mater Res A ; 111(10): 1500-1512, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37128974

RESUMO

The fabrication of biodegradable, bioabsorbable, and biocompatible vascular scaffolds with enhanced mechanical and biological properties that are able to modulate local inflammation and induce endothelialization after surgical implant is still a challenge. In this work, a fibrous scaffold, made of poly(ε-caprolactone) and poly(glycerol sebacate), was fabricated to be potentially used as a small-diameter graft in vascular surgery. The novelty of this research is represented by the direct incorporation of quercetin, a well-known antioxidant compound with several biological properties, into a polymeric scaffold obtaining a vascular construct able to modulate two key factors involved in postsurgical inflammation, matrix metalloproteinase-9 and endothelial nitric oxide synthase. For its production, an electrospinning apparatus, a solution made of the two polymers (both 20% (w/v), mixed at the ratio 1:1 (v/v)), and free quercetin (0.05% (w/v)) were used. Scanning electron and atomic force microscopies were employed to investigate the morphological properties of the fabricated electrospun scaffolds. Furthermore, physicochemical properties, including Fourier-transform infrared spectroscopy, mass loss, fluid uptake, quercetin release, mechanical properties, and biological activity of the scaffolds were studied. The expression of matrix metalloproteinase-9, tissue inhibitor of metalloproteinase-1, and of endothelial nitric oxide synthase was evaluated when the quercetin-functionalized scaffold was exposed to  human endothelial cells treated with tumor necrosis factor-α. The results of this study confirmed the feasibility of incorporating free quercetin during the electrospinning process to impart biological properties to small-diameter vascular prostheses.


Assuntos
Prótese Vascular , Humanos , Linhagem Celular , Sobrevivência Celular , Materiais Biocompatíveis/química , Quercetina/química
9.
Microvasc Res ; 83(3): 281-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22386654

RESUMO

Anoxia modulates the expression of molecules associated with endothelial dysfunction and vascular diseases. Polyphenols have potent antioxidant properties due to their ability to modulate genes involved in oxidative tissue damage. In this study, we investigated the effect of polyphenol extract from olive pomace (PEOP) and its main constituents, Tyrosol and Oleuropein, on endothelial cells subjected to anoxia by evaluating the expression of molecules critical for endothelial function, proliferation and migration, and the signaling pathway involved. EAhy926 human endothelial cells were exposed to anoxic stress in the presence or absence of PEOP. Anoxia increased the nitric oxide (NO) level and the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNFα). These effects were prevented by PEOP treatment in a dose-dependent manner. Moreover, PEOP prevented the proliferation and migration associated with anoxia in EAhy926 cells, down-regulated the levels of matrix metalloproteinase (MMP)-2, MMP-9 and membrane type-1 MMP (MT1-MMP) and increased tissue MMP inhibitor-1 (TIMP-1) expression. Purified Oleuropein or Tyrosol restored to a basal level the anoxia-induced expression of MMP-9 and partially of MMP-2. The expression of TNFα was reduced by both polyphenols in a dose-dependent manner, but more efficiently by Tyrosol. Conversely, Oleuropein and Tyrosol had no significant effects on iNOS, COX-2 and TIMP-1 expression when used at the concentration found in PEOP. PEOP induced a time-dependent phosphorylation of p38 MAPK and ERK1/2 and inhibited anoxia-induced NF-κB activation. PEOP treatment restores the endothelial functions that are impaired by anoxia by regulating the expression of genes involved in proteolysis, angiogenesis and inflammation more efficiently than the single purified components. Therefore, the combined use of polyphenols, as in PEOP, could represent a powerful tool for the treatment and chemoprevention of endothelial dysfunction-associated vascular diseases.


Assuntos
Endotélio Vascular/patologia , Hipóxia/metabolismo , Olea/metabolismo , Polifenóis/química , Relação Dose-Resposta a Droga , Humanos , Sistema de Sinalização das MAP Quinases , Metaloproteinase 14 da Matriz/biossíntese , Metaloproteinase 2 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/biossíntese , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Fosforilação , Prostaglandina-Endoperóxido Sintases/metabolismo , Fatores de Tempo , Inibidor Tecidual de Metaloproteinase-1/biossíntese , Fator de Necrose Tumoral alfa/metabolismo
10.
J Food Sci ; 85(3): 517-525, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32056210

RESUMO

Food supply chain is a rapidly growing integrated sector and covers all the aspects from farm to fork, including manufacturing, packaging, distribution, storing, as well as further processing or cooking for consumption. Along this chain, smart packaging could impact the quality, safety, and sustainability of food. Packaging systems have evolved to be smarter with integration of emerging electronics and wireless communication and cloud data solutions. Although there are many factors causing the loss and waste issues for foods throughout the whole supply chain of food and there have been several articles showing the recent advances and breakthroughs in developing smart packaging systems, this review integrates these conceptual frameworks and technological applications and focuses on how innovative smart packaging solutions are beneficial to the overall quality and safety of food supply by enhancing product traceability and reducing the amount of food loss and waste. We start by introducing the concept of the management for the integrated food supply chain, which is critical in tactical and operational components that can enhance product traceability within the entire chain. Then we highlight the impact of smart packaging in reducing food loss and waste. We summarize the basic information of the common printing techniques for smart packaging system (sensor and indicator). Then, we discuss the potential challenges in the manufacturing and deployment of smart packaging systems, as well as their cost-related drawbacks and further steps in food supply chain.


Assuntos
Embalagem de Alimentos/métodos , Abastecimento de Alimentos , Comércio , Eletrônica , Embalagem de Alimentos/economia , Embalagem de Alimentos/instrumentação , Abastecimento de Alimentos/economia
11.
J Biomed Mater Res A ; 107(9): 2063-2075, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31081994

RESUMO

Treatment of postsurgical infections, associated with orthopedic surgeries, has been a major concern for orthopedics. Several strategies including systematic and local administration of antibiotics have been proposed to this regard. The present work focused on fabricating alginate (Alg) modified brushite (Bru) cements, which could address osteogeneration and local antibiotic demands. To find the proper method of drug incorporation, Gentamicin sulfate (Gen) was loaded into the samples in the form of solution or powder. Several characterization tests including compression test, morphology, cytotoxicity, and cell adhesion assays were carried out to determine the proper concentration of Alg as a modifier of the Bru cement. The results indicated that addition of 1 wt% Alg led to superior mechanical and biological properties of the cement. Moreover, Alg addition changed the morphology of the cement from plate and needle-like structures to petal-like structure. Fourier transform infrared spectroscopy results confirmed the successful loading of Gen on the cements, specifically when Gen solution was used, and X-Ray Diffractometer result indicated that Gen caused a decrease in crystalline size. Furthermore, thermal analysis revealed that Gen-loaded sample had more stable structure as the transformation temperature slightly shifted to a higher one. The stability study confirmed the chemical stability and adequate mechanical performance of the cements within 1 month of soaking time. Finally, the addition of Alg has a positive impact on the release behavior at low concentration of Gen solution so that 20% decrease within 2 weeks of release experiment was remarkably detected.


Assuntos
Alginatos/química , Antibacterianos , Cimentos Ósseos/química , Fosfatos de Cálcio/química , Gentamicinas , Teste de Materiais , Osteoblastos/metabolismo , Antibacterianos/química , Antibacterianos/farmacocinética , Antibacterianos/farmacologia , Linhagem Celular , Gentamicinas/química , Gentamicinas/farmacocinética , Gentamicinas/farmacologia , Humanos , Osteoblastos/citologia
12.
J Biomater Appl ; 33(9): 1265-1276, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30961462

RESUMO

Traditional wound dressings are not effective enough to regulate the moisture content and remove excessive exudate from the environment. Wet wound dressings formed from hydrogels such as alginate are widely used in clinical practice for treatment of skin disorders. Here, we functionalize alginate dressings with natural antioxidants such as curcumin and t-resveratrol to render them both anti-inflammatory and antibacterial. The hydrogel maintains excellent mechanical properties and oxygen permeability over time. The release rate of the compounds from the hydrogels is assessed and their impact on bacterial and cellular growth is evaluated. The antioxidant compounds act as bactericidal agents and improve cell viability. The optimal concentration of active compounds in the engineered alginate-based dressings is determined.


Assuntos
Alginatos/química , Antioxidantes/administração & dosagem , Bandagens , Hidrogéis/química , Dermatopatias/tratamento farmacológico , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Anti-Inflamatórios não Esteroides/administração & dosagem , Antioxidantes/farmacologia , Materiais Biocompatíveis/química , Curcumina/administração & dosagem , Curcumina/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Humanos , Oxigênio/análise , Resveratrol/administração & dosagem , Resveratrol/farmacologia , Dermatopatias/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos
13.
Nat Prod Res ; 33(4): 589-592, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29126366

RESUMO

Processing of cocoa (Theobroma cacao L.) beans responsible for agricultural exports leads to large amounts of solid waste that were discarded, however, this one presents high contents of metabolites with biological activities. The major objective of this study was to valorise cocoa agroindustrial residue obtained by hydraulic pressing for extract rich in antioxidants. For it, the centesimal composition of residue was investigated, the green extraction was carried out from the residue after, the bioactive compounds, sugar contents and screaming by HPTLC were quantified for extract. The extract has a total polyphenol content of 229.64 mg/g and high antioxidant activity according to ABTS 225.0 µM/g. HTPLC analysis confirmed the presence in the extract, residue of terpenes, sesquiterpenes, flavonoids and antioxidant activity. These results, as a whole, suggest that the extract from the cocoa residue has interesting characteristics to alternative crops with potential industrial uses.


Assuntos
Antioxidantes/isolamento & purificação , Cacau/química , Extratos Vegetais/química , Polifenóis/análise , Antioxidantes/química , Chocolate/análise , Flavonoides/análise , Flavonoides/química , Resíduos Industriais/análise , Terpenos/análise , Terpenos/química
14.
Nat Prod Res ; 33(18): 2600-2608, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29656659

RESUMO

Cupuassu (Theobroma grandiflorum Schum.) is a popular Amazonian fruit because of its intense aroma and nutritional value, whose lipid fraction is alternatively used in cosmetics. To preserve active principles and ensure their controlled release, extract was microencapsulated by spray drying. Influence of spray-drying conditions on microencapsulation of cupuassu seed by-product extract was investigated according to a 33-Box Behnken factorial design, selecting inlet temperature, maltodextrin concentration and feed flowrate as independent variables, and total polyphenol and flavonoid contents, antiradical power, yields of drying and microencapsulation as responses. Fitting the results by second-order equations and modelling by Response Surface Methodology allowed predicting optimum conditions. Epicatechin and glycosylated quercetin were the major microencapsulated flavonoids. Microparticles showed satisfactory antiradical power and stability at 5 °C or under simulated gastrointestinal conditions, thus they may be used to formulate new foods or pharmaceuticals.


Assuntos
Cacau/química , Composição de Medicamentos/métodos , Extratos Vegetais/química , Sementes/química , Dessecação , Digestão , Flavonoides/análise , Hidrólise , Extratos Vegetais/análise , Extratos Vegetais/farmacocinética , Polifenóis/análise , Polissacarídeos/química , Quercetina/análise , Temperatura
15.
Food Chem Toxicol ; 109(Pt 2): 1103-1110, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28359876

RESUMO

An acidic thermostable protease was extracellularly produced either in shake flask or in stirred tank bioreactor by an Aspergillus foetidus strain isolated from the Brazilian savanna soil using different nitrogen sources. Its maximum activity (63.7 U mL-1) was obtained in a medium containing 2% (w/v) peptone. A cultivation carried out in a 5.0 L stirred-tank bioreactor provided a maximum protease activity 9% lower than that observed in Erlenmeyer flasks, which was obtained after a significantly shorter (by 16-29%) time. Protease purification by a combination of gel-filtration chromatography resulted in a 16.9-fold increase in specific activity (248.1 U g-1). The estimated molecular weight of the purified enzyme was 50.6 kDa, and the optimal pH and temperature were 5.0 and 55 °C, respectively. The enzyme was completely inhibited by pepstatin A, and its activity enhanced by some metals. According to the inhibition profiles, it was confirmed that the purified acid protease belongs to the aspartic protease type. These results are quite promising for future development of large-scale production of such protease, which can be useful in biotechnological applications requiring high enzyme activity and stability under acidic conditions.


Assuntos
Ácido Aspártico Proteases/química , Ácido Aspártico Proteases/isolamento & purificação , Aspergillus/enzimologia , Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Ácido Aspártico Proteases/genética , Ácido Aspártico Proteases/metabolismo , Aspergillus/química , Aspergillus/genética , Aspergillus/isolamento & purificação , Brasil , Estabilidade Enzimática , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Concentração de Íons de Hidrogênio , Peso Molecular , Microbiologia do Solo , Especificidade por Substrato , Temperatura
16.
Biotechnol Prog ; 32(2): 279-84, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-26697953

RESUMO

The freshwater microalga Chlorella vulgaris was cultured batchwise on the seawater-simulating Schlösser medium either in a 1.1-L-working volume helicoidal photobioreactor (HeP) or Erlenmeyer flask (EF) as control and continuously supplying air as CO2 source. In these systems, maximum biomass concentration reached 1.65 ± 0.17 g L(-1) and 1.25 ± 0.06 g L(-1) , and maximum cell productivity 197.6 ± 20.4 mg L(-1)  day(-1) and 160.8 ± 12.2 mg L(-1)  day(-1) , respectively. Compared to the Bold's Basal medium, commonly employed to cultivate this microorganism on a bench-scale, the Schlösser medium ensured significant increases in all the growth parameters, namely maximum cell concentration (268% in EF and 126% in HeP), maximum biomass productivity (554% in EF and 72% in HeP), average specific growth rate (67% in EF and 42% in HeP), and maximum specific growth rate (233% in EF and 22% in HeP). The lipid fraction of biomass collected at the end of runs was analyzed in terms of both lipid content and fatty acid profile. It was found that the seawater-simulating medium, despite of a 56-63% reduction of the overall biomass lipid content compared to the Bold's Basal one, led in HeP to significant increases in both the glycerides-to-total lipid ratio and polyunsaturated fatty acid content compared to the other conditions taken as an average. These results as a whole suggest that the HeP configuration could be a successful alternative to the present means to cultivate C. vulgaris as a lipid source. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:279-284, 2016.


Assuntos
Chlorella vulgaris/química , Chlorella vulgaris/metabolismo , Meios de Cultura/química , Lipídeos/biossíntese , Fotobiorreatores , Água do Mar/química , Ar , Biomassa , Chlorella vulgaris/citologia , Lipídeos/química
17.
Mater Sci Eng C Mater Biol Appl ; 46: 374-80, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25492000

RESUMO

Polysaccharide-based nanostructured polymeric microcapsules were fabricated by the electrostatic layer-by-layer self-assembly technique and used to encapsulate mixtures of four different polyphenols in order to achieve their controlled release. The real-time fabrication of the dextran/chitosan multilayer was monitored by quartz crystal microbalance with dissipation monitoring, and the morphology of the nanostructured polymeric capsules was characterized by scanning electron microscopy. The polyphenol encapsulation was obtained by reversible permeability variation of the capsule shell in ethanol:water mixtures. The loading efficiency in different water:ethanol mixtures and the release rate in acidic conditions were characterized by UV spectroscopy and HPLC. The higher loading efficiency was obtained with an ethanol:water 35:65 phenolic solution, equal to 42.0±0.6%, with a total release of 11.5±0.7 mg of total polyphenols per 11.3 µL of microcapsules after 240 min of incubation in acidic environment. The results suggest that polysaccharide-based capsules can be successfully used to encapsulate and release low water-soluble molecules, such as polyphenols.


Assuntos
Quitosana/química , Dextranos/química , Polifenóis/administração & dosagem , Cromatografia Líquida de Alta Pressão , Microscopia Eletrônica de Varredura , Espectrofotometria Ultravioleta
18.
Colloids Surf B Biointerfaces ; 136: 1067-72, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26590900

RESUMO

Apigenin is an antioxidant that has shown a preventive activity against different cancer and cardiovascular disorders. In this study, we encapsulate apigenin with liposome to tackle the issue of its poor bioavailability and low stability. Apigenin loaded liposomes are fabricated with food-grade rapeseed lecithin in an aqueous medium in absence of any organic solvent. The liposome particle characteristics, such as particle size and polydispersity are optimised by tuning ultrasonic processing parameters. In addition, to measure the liposome encapsulation efficiency accurately, we establish a unique high-performance liquid chromatography technique in which an alkaline buffer mobile phase is used to prevent apigenin precipitation in the column;. salt is added to separate lipid particles from the aqeuous phase. Our results demonstrate that apigenin encapsulation efficiency is nearly 98% that is remarkably higher than any other reported value for encapsulation of this compound. In addition, the average particle size of these liposomes is 158.9 ± 6.1 nm that is suitable for the formulation of many food products, such as fortified fruit juice. The encapsulation method developed in this study, therefore have a high potential for the production of innovative, functional foods or nutraceutical products.


Assuntos
Antioxidantes/química , Lipossomos , Calorimetria , Cromatografia Líquida de Alta Pressão , Ensaio de Desvio de Mobilidade Eletroforética
19.
Adv Healthc Mater ; 4(14): 2146-2153, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26304467

RESUMO

Hydrogel templates are formed to entrap various pre-polymers prior to their crosslinking process. Upon the completion of the crosslinking process, an independent polymer network with the same fiber geometry is formed. The hydrogel template can be removed if necessary. As the proof-of-principle, fibers from various polymers are fabricated. The fabricated hybrid polymeric fibers are bioactive and can be bioprinted or assembled using textile processes. The approach can be used for creating complex 3D constructs for various applications.

20.
Int J Biol Macromol ; 81: 17-21, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26210038

RESUMO

The kinetics of a thermostable extracellular acid protease produced by an Aspergillus foetidus strain was investigated at different pH, temperatures and substrate concentrations. The enzyme exhibited maximal activity at pH 5.0 and 55°C, and its irreversible deactivation was well described by first-order kinetics. When temperature was raised from 55 to 70°C, the deactivation rate constant increased from 0.018 to 5.06h(-1), while the half-life decreased from 37.6 to 0.13h. The results of activity collected at different temperatures were then used to estimate, the activation energy of the hydrolysis reaction (E*=19.03kJ/mol) and the standard enthalpy variation of reversible enzyme unfolding (ΔH°U=19.03kJ/mol). The results of residual activity tests carried out in the temperature range 55-70°C allowed estimating the activation energy (E(*)d=314.12kJ/mol), enthalpy (311.27≤(ΔH°d≤311.39kJ/mol), entropy (599.59≤ΔS(*)d≤610.49kJ/mol K) and Gibbs free energy (103.18≤ΔG(*)d≤113.87kJ/mol) of the enzyme irreversible denaturation. These thermodynamic parameters suggest that this new protease is highly thermostable and could be important for industrial applications. To the best of our knowledge, this is the first report on thermodynamic parameters of an acid protease produced by A. foetidus.


Assuntos
Aspergillus/enzimologia , Peptídeo Hidrolases/química , Termodinâmica , Caseínas/química , Ativação Enzimática , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Especificidade por Substrato , Temperatura
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