Thermal and ultraviolet-visible light stability kinetics of co-nanoencapsulated carotenoids.

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The Production, Characterization, and the Stability of Carotenoids Loaded in Lipid-Core Nanocapsules.

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Colorants in Cheese Manufacture: Production, Chemistry, Interactions, and Regulation

Colored Cheddar cheeses are prepared by adding an aqueous annatto extract (norbixin) to cheese milk; however, a considerable proportion (∼20%) of such colorant is transferred to whey, which can limit the end use applications of whey products. Different geographical regions have adopted various strategies for handling whey derived from colored cheeses production. For example, in the United States, whey products are treated with oxidizing agents such as hydrogen peroxide and benzoyl peroxide to obtain white and colorless spray‐dried products; however, chemical bleaching of whey is prohibited in Europe and China. Fundamental studies have focused on understanding the interactions between colorants molecules and various components of cheese. In addition, the selective delivery of colorants to the cheese curd through approaches such as encapsulated norbixin and microcapsules of bixin or use of alternative colorants, including fat‐soluble/emulsified versions of annatto or beta‐carotene, has been studied. This review provides a critical analysis of pertinent scientific and patent literature pertaining to colorant delivery in cheese and various types of colorant products on the market for cheese manufacture, and also considers interactions between colorant molecules and cheese components; various strategies for elimination of color transfer to whey during cheese manufacture are also discussed

Desenvolvimento e avaliação da estabilidade de nanocapsulas de luiteína

Os carotenoides são pigmentos amplamente distribuídos na natureza e estão presentes, em sua maioria, nos tecidos vegetais. Nos últimos anos, diversos estudos sugerem que o consumo de frutas e verduras com elevado teor destes compostos bioativos, está associado à diminuição da incidência de algumas doenças em seres humanos. No entanto, os carotenoides apresentam algumas características indesejáveis como a instabilidade frente à luz, ao calor e ao oxigênio, além da insolubilidade em meio aquoso, o que os torna, sob certo aspecto, inviáveis para a utilização em formulações alimentares e farmacêuticas. Neste contexto, o presente estudo desenvolveu nanocápsulas poliméricas, contendo luteína, com o objetivo de melhorar a solubilidade e estabilidade deste carotenoide. As nanocápsulas de luteína foram desenvolvidas pela técnica de deposição interfacial do polímero pré-formado poli (e-caprolactona). Os cristais de luteína foram obtidos a partir de flores de Tagetes patula por extração exaustiva usando tetrahidrofurano para obtenção de luteína 92% pura. Paralelamente, os ésteres de luteína foram extraídos utilizando-se um sistema de extração com fluido supercrítico de CO2 e etanol a 10%. As nanocápsulas foram preparadas, caracterizadas e sua estabilidade investigada. Os resultados mostraram distribuição de tamanho monomodal com índice de polidispersão de 0,11 ± 0,02, diâmetro médio de 191,90 ± 3,24 nm, potencial zeta de –5,14 ± 2,22 mV e eficiência de encapsulação de 99,51%. As propriedades físico-químicas da suspensão de nanocápsulas poliméricas foram avaliadas em função do tempo de armazenamento para determinar a estabilidade da formulação. Após 60 dias de armazenamento (4 °C), a nanocápsula manteve-se estável, sem alterações significativas no diâmetro e cor (p ≥ 0,05); e o conteúdo residual de luteína foi de 36% em relação ao valor inicial. No entanto, a nanocápsula armazenada a 25 °C apresentou alterações no potencial zeta, pH, valores de cor e conteúdo residual ao longo do tempo, quando comparada às nanocápsulas armazenadas a 4 °C. O teor de luteína nas nanocápsulas após 90 dias de armazenamento a 4 °C e 25 °C apresentou valores superiores aos da luteína livre, após 30 dias de armazenamento nas mesmas condições. Outro estudo realizado neste trabalho foi a avaliação da estabilidade da luteína (92% de pureza) nas nanocápsulas produzidas, durante fotossensibilização (5-25 °C) e aquecimento (70-90 °C) em sistema modelo. Durante a fotossensibilização e aquecimento, a luteína nanoencapsulada exibiu energia de ativação (Ea) de 24,67 kcal/mol e 9,96 Kcal/mol, respectivamente, e estes valores foram superiores aos valores para luteína livre relatados em outros estudos para ambos os experimentos. Assim, a nanoencapsulação permitiu a solubilização da luteína em meio aquoso, aumentou a estabilidade da luteína frente ao tratamento térmico e radiação luminosa.Carotenoids are pigments widely distributed in nature and are mostly present in plant tissues. In recent years, several studies have suggested that the consumption of fruits and vegetables with a high content of these bioactive compounds are associated with a decrease in the incidence of some diseases in humans. However, carotenoids exhibit some undesirable characteristics such as instability against light, heat and oxygen, as well as insolubility in aqueous media, which makes them in some ways unviable for use in food and pharmaceutical formulations. In this context, the present study developed polymeric nanocapsules, containing lutein, with the aim of improving the solubility and stability of this carotenoid. Lutein nanocapsules were developed by the technique of interfacial deposition of the preformed polymer poly-ɛ-caprolactone. The lutein crystals were obtained from Marigold flowers by exhaustive extraction using tetrahydrofuran to obtention of lutein 92 % pure. In parallel, the lutein esters were extracted using a supercritical fluid extraction system with CO2 and ethanol 10%. The nanocapsules were prepared, characterized and their stability investigated. The results showed monomodal size distribution with polydispersity index of 0.11 ± 0.02, z-average of 191.90 ± 3.24 nm, zeta potential of –5.14 ± 2.22 mV and encapsulation efficiency of 99.51%. The physicochemical properties of polymeric nanocapsules suspension were evaluated in function of storage time to determine the formulation stability. After 60 days of storage (4 °C) the nanocapsules were stable without significant changes in diameter and color (p ≥ 0.05); and residual content of lutein was 36 % relative to initial value. However, nanocapsules stored at 25 °C presented changes in zeta potential, pH, color values and residual content over time when compared to nanocapsules stored at 4 °C. Lutein content in the nanocapsules after 90 days of storage at 4 °C and 25 °C presented superior values than free lutein after 30 days of storage in same conditions. Thus, the nanoencapsulation allowed the solubilization of lutein in aqueous medium and increased the stability of lutein in different temperatures. Another study carried out in this work was to evaluate the stability of lutein (92% of purity) in lipid-core nanocapsules, prepared by interfacial deposition of preformed polymer, during photosensitization (5-25 °C) and heating (70-90 °C). During photosensitization and heating, nanocapsules exhibited activation energy (Ea) of 24.67 kcal/mol and 9.96 Kcal/mol, respectively, and these values to nanocapsules were superior than free lutein values reported in other studies for both experiments. The results obtained in this study suggest that nanotechnology can improve the stability of lutein. Thus, the nanoencapsulation allowed the solubilization of lutein in aqueous medium, increased the stability of lutein against heat treatment and light radiation

Sintesis dan Uji Fotostabilitas Kompleks Zn(II)-Astaxanthin

Astaxanthin is a pigment from the carotenoid group found in algae, shrimp, and crabs. Due to its chemical structure, astaxanthin has many health benefits but low stability against direct exposure to light and oxygen. In this study, the Zn-astaxanthin complex was synthesized using a reflux reactor at 37o and 60oC. Complex compounds were analyzed using a UV-Vis spectrophotometer and FTIR. The UV-Vis spectrophotometer analysis showed a bathochromic shift in acetone (475 to 477 nm). In comparison, in dimethyl sulfoxide, a hypsochromic shift (493 to 475 nm) was observed, and a new absorption peak was observed at 330 nm. FTIR analysis shows a decrease in the intensity of the C=O stretching vibration and -OH group vibration at 1712 and 1219 cm-1, respectively. This indicated an interaction between the metal ion Zn2+ and astaxanthin. Zn-astaxanthin has better stability than astaxanthin during irradiation, using a halogen lamp at a light intensity of 300 W/m2 for 6 hours. Based on the zero-order degradation kinetics model, the degradation rate constant of the Zn-astaxanthin complex was 0.0621, smaller than that of astaxanthin (0.0880)

Effects of surface characteristics of polymeric nanocapsules on the pharmacokinetics and efficacy of antimalarial quinine

Introduction: The surface charge of nanoparticles, such as nanospheres (NS) and nanocapsules (NC), has been studied with the purpose of improving the in vivo performance of drugs. The aim of this study was to develop, characterize, and evaluate the in vitro antimalarial efficacy of NCP80 and NSP80 (polysorbate coated) or NCEUD and NSEUD (prepared with Eudragit RS 100) loading quinine (QN). Methods: Formulations were prepared by the nanoprecipitation method, followed by wide physicochemical characterization. Antimalarial activity in Plasmodium berghei-infected mice and populational pharmacokinetics (PopPK) in rats were evaluated. Results: The formulations showed a nanometric range (between 138 ± 3.8 to 201 ± 23.0 nm), zeta potential (mV) of −33.1 ± 0.7 (NCP80), −30.5 ± 1 (UNCP80), −25.5 ± 1 (NSP80), −20 ± 0.3 (UNSP80), 4.61 ± 1 (NCEUD), 14.1 ± 0.9 (UNCEUD), 2.86 ± 0.3 (NSEUD) and 2.84 ± 0.6 (UNSEUD), content close to 100%, and good QN protection against UVA light. There was a twofold increase in the penetration of QN into infected erythrocytes with NC compared to that with NS. There was a significant increase in t1/2 for all NC evaluated compared to that of Free-QN, due to changes in Vdss. PopPK analysis showed that NCP80 acted as a covariate to Q (intercompartmental clearance) and V2 (volume of distribution in the peripheral compartment). For NCEUD, V1 and Q were modified after QN nanoencapsulation. Regarding in vivo efficacy, NCEUD increased the survival of mice unlike Free-QN. Conclusion: Cationic nanocapsules modified the pharmacology of QN, presenting a potential alternative for malaria treatment

Nanoencapsulamento de óleo de chia e zeaxantina utilizando mucilagens como material estruturante : desenvolvimento, caracterização e aplicação

O interesse em ácidos graxos poli-insaturados e compostos bioativos tem aumentado nos últimos anos, por contribuírem na diminuição do risco de desenvolver doenças, tais como câncer e doenças cardiovasculares. Entre os óleos que contem ácidos graxos poli-insaturados, o óleo de chia se destaca por possuir alto teor de ômega 3. Entre os carotenoides, a zeaxantina representa potencial para ser aplicada em alimentos por atuar na diminuição do risco de desenvolver doenças oculares. No entanto, tais compostos são instáveis na presença de luz, calor e oxigênio e insolúveis ou pouco solúveis em água, o que limita sua aplicação em alimentos. Diante disso, o nanoencapsulamento representa uma alternativa promissora para aumentar a estabilidade e permitir a dispersão desses compostos em alimentos ricos em água. No intuito de oferecer produtos mais naturais aos consumidores, os materiais sintéticos utilizados no encapsulamento têm sido substituídos por polímeros naturais, como as mucilagens. Nesse contexto, no primeiro estudo, nanopartículas de óleo de chia (CSO-NP) foram desenvolvidas com mucilagem de chia como material estruturante. Em um segundo estudo, desenvolveu-se nanopartículas de zeaxantina (Zea-NP) utilizando mucilagem do cladódio de cacto (Opuntia monacantha) como material estruturante Na terceira parte da pesquisa, no intuito de avaliar a influência da adição de nanopartículas em uma matriz alimentícia rica em água e verificar sua estabilidade quando incorporadas em um alimento, além de enriquecer um produto com zeaxantina e aumentar seu valor agregado, as nanopartículas de zeaxantina (Zea-NP) foram incorporadas em iogurte, por ser um alimento amplamente consumido e por possuir alta quantidade de água. Inicialmente, ambas as nanopartículas desenvolvidas foram caracterizadas em relação ao tamanho da partícula, potencial zeta, valor de span, eficiência de encapsulação, morfologia, pH, viscosidade, propriedades térmicas e espectroscopia no infravermelho (FT-IR). A capacidade de carga das CSO-NP e cor das Zea-NP também foram avaliadas. As CSO-NP e uma emulsão desenvolvida, a fim de comparações, tiveram sua estabilidade avaliada durante 28 dias de armazenamento em condições aceleradas (40 ºC), sem a presença de luz. A estabilidade das Zea-NP e de uma nanoemulsão de zeaxantina (Zea-NE) também foi avaliada em diferentes temperaturas (4, 25 e 40 ºC), durante 28 dias, na ausência de luz. Para avaliar a aplicação das Zea-NP em uma matriz alimentícia, três formulações de iogurte foram desenvolvidas: controle (CY), com adição de nanopartículas (Y-NP) e com adição de nanoemulsão (Y-NE) Os iogurtes foram armazenados durante 28 dias a 4 ºC em potes plásticos fechados e suas características físico-químicas e a retenção de zeaxantina em Y-NP e Y-NE foram avaliadas semanalmente. As caraterísticas sensoriais e morfologia do CY, Y-NP e Y-NE foram avaliadas logo após o preparo. Também foi realizada a análise de digestão in vitro, a fim de avaliar a bioacessibilidade da zeaxantina em Y-NP e Y-NE. Os resultados do primeiro estudo demonstraram que as CSO-NP apresentaram formato esférico, diâmetro médio de 205 ± 4,24 nm, potencial zeta de - 11,58 ± 1,87 mV e valor de span de 1,76 ± 0,09, o que indicou uma distribuição de partícula homogênea. Além disso, as CSO-NP apresentaram alta eficiência de encapsulação (82,8%) e capacidade de carga de 35,38%. Ao longo do armazenamento não foram verificadas mudanças significativas no valor de span e potencial zeta e apesar de ter ocorrido aumento significativo no diâmetro da partícula ao final do período e de terem sido observadas mudanças no pH, as CSO-NP apresentaram maior estabilidade que a emulsão ao longo do armazenamento em condições aceleradas. Conforme os resultados do segundo estudo, as Zea-NP apresentaram formato esférico, diâmetro médio de 184 ± 3,54 nm, potencial zeta de -14,8 ± 0,42 mV, valor de span de 1,18 ± 0,06 e eficiência de encapsulação de 96,57% Durante o armazenamento em diferentes temperaturas, as Zea-NP não apresentaram alterações significativas no valor de span, pH e cor. Em relação ao diâmetro da partícula, foi observado um aumento nas amostras armazenadas nas temperaturas de 25 e 40 ºC após o primeiro dia de armazenamento, que permaneceu constante até o fim do período. Apesar dessas mudanças, as Zea-NP apresentaram estabilidade satisfatória, ao considerar que ao final do armazenamento a 25 e a 40 ºC, apresentaram 39,66% e 31,30% de retenção de zeaxantina, respectivamente, enquanto que para as Zea-NE, a retenção do carotenoide foi de 20,64% e 0,73% nas mesmas temperaturas. Quando as Zea-NP foram armazenadas a 4 ºC, verificou-se que houve uma maior retenção de zeaxantina (56,29%). De acordo com os resultados do terceiro estudo, ao final do período de armazenamento, o Y-NP apresentou maior pH e menor acidez do que o CY, além de maior intensidade de cor b*, devido à presença do carotenoide. Apesar do Y-NP ter demonstrado menor viscosidade e maior sinérese do que o CY, essas alterações não foram perceptíveis na análise sensorial. Além disso, ao final do armazenamento a retenção de zeaxantina foi de 22,31% no Y-NP e 16,84% no Y-NE. Quanto à digestão in vitro, o Y-NP apresentou menor concentração de zeaxantina nas micelas do que o Y-NE e consequentemente menor bioacessibilidade, o que pode sugerir que as Zea-NP forneceram uma liberação controlada do carotenoide. Os resultados deste trabalho evidenciaram que foi possível obter nanopartículas com características adequadas e com alta estabilidade, através do uso da mucilagem de chia e da mucilagem de cacto como material estruturante, o que viabiliza o uso dessas mucilagens em substituição a polímeros sintéticos no nanoencapsulamento Devido as características satisfatórias, ambas as nanopartículas obtidas demonstraram potencial para serem aplicadas em alimentos. Além disso, quando incorporadas em iogurte, apesar de as nanopartículas de zeaxantina terem apresentado menor bioacessibilidade, ainda apresentaram vantagem em relação à nanoemulsão, devido à sua capacidade de proteção ao composto encapsulado, o que conferiu maior estabilidade ao carotenoide. Tais resultados indicam que as nanopartículas possuem potencial de utilização em processos industriais e tecnológicos.The interest in polyunsaturated fatty acids and bioactive compounds has increased in the last years, due to its contribution in reducing the risk of developing diseases, such as cancer and cardiovascular diseases. Among oils which contain polyunsaturated fatty acids, chia oil stands out due to its high omega 3 content. Among the carotenoids, zeaxanthin represents potential to be applied in foods due to its capacity in reducing the risk of developing eye diseases. However, such compounds are unstable in the presence of light, heat and oxygen and insoluble or poorly soluble in water, which limits its application in food. In this view, nanoencapsulation represents a promising alternative to increase stability and allow dispersion of these compounds in water-rich foods. In order to offer more natural products to consumers, the synthetic materials used in encapsulation have been replaced by natural ones, such as mucilages. In this context, in the first study, chia oil nanoparticles (CSO-NP) were developed with chia mucilage as structuring material. In a second study, zeaxanthin nanoparticles (Zea-NP) were developed using cactus cladode mucilage (Opuntia monacantha) as structuring material. In the third part of the research, in order to evaluate the influence of nanoparticles addition in a water-rich food matrix and to verify its stability when incorporated into a food, besides enriching a product with zeaxanthin and add value, zeaxanthin nanoparticles (Zea-NP) were incorporated into yogurt, due to its ample comsuption and high water amount. Initially, both developed nanoparticles were characterized in terms of particle size, zeta potential, span value, encapsulation efficiency, morphology, pH, viscosity, thermal properties and infrared (FT-IR) spectroscopy The loading capacity of CSO-NP and Zea-NP color were also evaluated. CSO-NP and an emulsion developed for comparative purposes, had their stability evaluated for 28 days of storage under accelerated conditions (40 °C), without light presence. The stability of Zea-NP and a zeaxanthin nanoemulsion (Zea-NE) was also evaluated at different temperatures (4, 25 and 40 °C) for 28 days in the absence of light. To evaluate the Zea-NP application in a food matrix, three yogurt formulations were developed: control (CY), with nanoparticles addition (Y-NP) and with nanoemulsion addition (Y-NE). Yogurts were stored for 28 days at 4 °C in closed plastic pots and their physicochemical characteristics and zeaxanthin retention in Y-NP and Y-NE were evaluated weekly. The sensory characteristics and morphology of CY, Y-NP and Y-NE were evaluated after preparation. In vitro digestion analysis was also performed to evaluate the zeaxanthin bioaccessibility in Y-NP and Y-NE. The results of the first study showed that CSO-NP presented spherical shape, mean diameter of 205 ± 4.24 nm, zeta potential of - 11.58 ± 1.87 mV and span value of 1.76 ± 0.09, which indicated a homogeneous particle distribution. In addition, CSO-NP presented high encapsulation efficiency (82.8 %) and load capacity of 35.38 % No significant changes in span and zeta potential values were observed during storage, and although there was a significant increase in particle size at the end of the period and changes in pH, CSO-NP presented higher stability than emulsion during storage at accelerated conditions. According to the results of the second study, the Zea-NP presented spherical shape, mean diameter of 184 ± 3.54 nm, zeta potential of - 14.8 ± 0.42 mV, span value of 1.18 ± 0.06 and encapsulation efficiency of 96.57 %. During storage at different temperatures, Zea-NP did not show significant changes in the span value, pH and color. Regarding the particle size, an increase in samples stored at temperatures of 25 and 40 ºC was observed after the first day of storage, which remained constant until the end of the period. Despite these changes, Zea-NP presented satisfactory stability, considering that at the end of the storage at 25 and 40 ºC, presented 39.66 % and 31.30 % of zeaxanthin retention, respectively, whereas for Zea-NE, carotenoid retention was 20.64 % and 0.73 % at the same temperatures. When stored at 4 °C, Zea-NP presented higher zeaxanthin retention (56.29 %) According to the results of the third study, at the end of the storage period, Y-NP presented higher pH and lower acidity than CY and higher intensity in color b* due to the presence of the carotenoid. Although Y-NP showed lower viscosity and higher syneresis than CY, these changes were not perceived in sensory analysis. In addition, at the end of storage, zeaxanthin retention was 22.31 % in Y-NP and 16.84 % in Y-NE. Regarding in vitro digestion, Y-NP presented lower zeaxanthin concentration in micelles than Y-NE, and consequently lower bioaccessibility, which may suggest that Zea-NP provided a controlled release of the carotenoid. The results of this work showed that it was possible to obtain nanoparticles with adequate characteristics and high stability using chia and cactus mucilage as structuring materials, which allows the use of these mucilages in substitution to synthetic polymers in nanoencapsulation. Due to the satisfactory characteristics, both obtained nanoparticles showed potential to be applied in food. In addition, when incorporated into yogurt, although the zeaxanthin nanoparticles showed less bioaccessibility, they still had advantage over nanoemulsion, due to its capacity to protect the encapsulated compound, which conferred greater stability to the carotenoid. These results indicate that nanoparticles have potential to be used in industrial and technological processes

Filmes de poli(ácido lático) adicionados de extratos de carotenoides – desenvolvimento de materiais para a embalagem de alimentos sensíveis à luz e ao oxigênio

A busca por alimentos livres de aditivos artificiais embalados em materiais que não agridam ao meio ambiente é uma tendência. Tendo em vista que o uso de embalagens que protegem os alimentos da luz e do oxigênio permite a extensão do shelf life de produtos perecíveis, a incorporação de extratos de carotenoides à matriz polimérica do poli(ácido lático) (PLA) é uma alternativa para melhorar as propriedades desse polímero e ampliar sua gama de aplicação. Inicialmente, extratos de beta-caroteno, licopeno e bixina foram incorporados à matriz de PLA em filmes produzidos pela técnica de casting, onde a bixina apresentou a maior estabilidade de coloração dos filmes e o melhor desempenho na proteção do óleo de girassol frente a reações de oxidação. Os filmes com licopeno e beta-caroteno protegeram o óleo através da barreira à luz, onde a liberação gradual de carotenoides para o óleo teve papel secundário na redução da formação de peróxidos no produto. A cinética de migração dos carotenoides para um líquido simulante foi descrita por um novo modelo matemático, onde a degradação dos compostos liberados foi considerada. Na segunda etapa do estudo, filmes de PLA com bixina foram produzidos através de processamento via fusão, onde o processamento a 160 °C provocou perdas de até 85% dos carotenoides. No entanto, o uso de 0,1% de bixina produziu materiais com excelentes propriedades de barreira à luz UV, a qual foi responsável pela expressiva redução da fotodegradação da riboflavina. As tensões de cisalhamento inerentes ao processamento em câmera de mistura não causaram degradação adicional da bixina, sendo possível manter boa parte do poder corante do carotenoide. Apesar de aumentar a permeabilidade ao oxigênio do material, o uso de plastificante acetil tribul citrato (ATBC) acelerou a migração da bixina para o alimento evitando que a degradação oxidativa do óleo de girassol ocorresse de forma acelerada. O desenvolvimento de filmes a partir de PLA e carotenoides demonstra que é possível produzir embalagens biodegradáveis, de coloração atrativa, mecanicamente resistentes e que protejam os alimentos embalados da fotodegradação. Através do conhecimento gerado, é desejável otimizar o desempenho do PLA como material antioxidante através da modulação da cinética de migração dos carotenoides e do aumento da barreira ao oxigênio do material.Consumers demand for food produced without synthetic and chemical preservatives packaged in environmentally friendly materials is a trend. Considering the shelf life of perishable food, it can be extended by the use of packaging materials that protects it from light and oxygen. The incorporation of carotenoid extracts into the poly (lactic acid) (PLA) matrix is an alternative to improve the properties of this polymer and to broaden its application range. Initially, beta-carotene, lycopene and bixin extracts were used to produce PLA films by the casting technique, where bixin produced films with the highest color stability and the best performance in protecting sunflower oil against oxidation. Lycopene and beta-carotene films protected the oil through a light barrier, where the gradual release of carotenoids to the oil played a secondary role in reducing the formation of peroxides in the product. A new mathematical model described the kinetics of carotenoid migration to a food simulant, where the degradation of the released compounds was considered. In the second part of the study, PLA films with bixin were produced by melt processing at 160 °C, where the heat caused up to 85% of carotenoid degradation. However, the use of 0.1% bixin produced materials with excellent UV-light barrier, which was responsible for significantly protecting riboflavin from photodegradation. The shear stress inherent to the melt mixing process did not cause bixin further degradation, where the coloring properties of the carotenoid in PLA were maintained. Despite increasing the oxygen permeability of the material, the use of acetyl tributyl citrate (ATBC) accelerated bixin migration to the food and prevented the increase of sunflower oil oxidative degradation. The development of PLA materials with carotenoids demonstrates that it is possible to produce colored food packaging that protects packaged food from photodegradation, besides being biodegradable and mechanically resistant. Through the knowledge generated, it is desirable to optimize the performance of PLA as an antioxidant material by modulating the carotenoid migration kinetics and increasing the material's oxygen barrier properties

Síntese e caracterização de uma nova pasta endodôntica com sistemas carreadores de fármacos

O objetivo do presente estudo foi sintetizar e caracterizar um material reparador para uso endodôntico com propriedades anti-inflamatória, antimicrobiana e remineralizante. A pasta experimental tem como propósito ser um sistema carreador de fármacos para regiões de difícil acesso em Odontologia. A apresentação do material é em forma de pó:líquido. No pó se encontra α-fosfato tricálcico, tungstato de cálcio e microesferas de amoxicilina (AMX-MS), já no líquido estão contidas nanocápsulas de indometacina (IndOHNC). A pasta experimental foi testada em relação a suas características físicoquímicas e biológicas. As AMX-MS obtiveram tamanho de 1,604 μm ± 0,08, forma esférica confirmada por MEV e teor da droga foi 1,63 mg g-1. As IndOHNC obtiveram tamanho de 162 ± 7,5 nm e forma esférica confirmada por MET. O teor do fármaco foi de 1 mg mL-1 ± 0,02. O escoamento da pasta foi de 18.56 ± 0.29, a espessura de película obtida foi 33 μm e radiopacidade de 1,81 mmAl. A pasta experimental demonstrou atividade antibacteriana contra o Enterococcus faecalis. A maior concentração de pasta experimental apresentou o maior valor em relação à viabilidade celular, com 187,03% no teste SRB. A atividade da enzima fosfatase alcalina e a formação de nódulos mineralizados obtiveram um gradual aumento em função do tempo. A migração celular demonstrou fechamento da ferida, e a pasta experimental foi capaz de acelerar o processo (p<0.05). Em conclusão, a pasta experimental demonstrou propriedades físico químicas e biológicas confiáveis, podendo ser um material promissor para o reparo da região periapical.The aim of this study was to synthesize and characterize a new reparative material with anti-inflammatory, antimicrobial and remineralizing properties. The reparative material was developed to be a drug delivery system for regions with difficult access in Dentistry. The formulation is presented in powder/liquid. The powder is composed of α-tricalcium phosphate, calcium tungstate and amoxicillin microspheres (AMX-MS). The liquid is composed of nanocapsules containing indomethacin (IndOH-NC). The physicochemical and biological properties of the experimental endodontic paste were evaluated. The AMX-MS obtained a mean size of 1.604 μm ± 0.08, spherical shape and the encapsulation capacity was 1.63 mg g-1. IndOH-NCs obtained a mean size of 162 ± 7.5 nm and spherical shape confirm by MET. The content of the encapsulated drug was 1 mg mL-1 ± 0.02. The experimental paste flow was 18.56 ± 0.29 mm, mean film thickness was 33 μm and radiopacity equivalent to 1.81 mmAl. The experimental paste showed antibacterial activity against Enterococcus faecalis. The highest concentration of experimental paste presented the highest value in cell viability (187.03% in SRB test). The activity of the phosphatase alkaline enzyme and the formation of mineralized nodules showed a gradual increase as a function of time. Cell proliferation showed continuous wound closure, and the experimental paste was able to accelerate the process (p<0.05). In conclusion, the experimental paste demonstrated reliable physicochemical and biological properties, and it could be a promising material for periapical region repair

Encapsulation of lactase in dispersible biopolymer particles as a potential delivery system to control lactose hydrolysis in milk

Encapsulation of lactase has been considered as an alternate strategy to overcome lactose intolerance and negative sensory properties of lactose-free milk if capsules can be dispersed in milk, retain lactase during storage, and selectively release lactase in the intestines after ingestion. The overall objective of this thesis was to study lactase-loaded biopolymer capsules with characteristics suitable for delivering lactase in milk. Lactase-loaded zein/pectin capsules were prepared by antisolvent precipitation of zein with assistance of ionic cross-linking of low-methoxyl sugar beet pectin (SBP) with Ca2+. Mass ratios of zein:SBP and CaCl2:SBP were studied for impacts on encapsulation efficiency, particle size and morphology, zeta potential, and stability and turbidity of dispersions. Encapsulation of lactase was verified using electrophoresis of capsules. The capsule formation mechanisms were additionally studied for surface hydrophobicity (H0), dispersion stability, and fluorescence spectroscopy as affected by molecular force blockers. Capsules were assessed for release kinetics at 4, 25, and 37 °C at pH 7, lactose hydrolysis during 3-week storage in whole and skim milk, and lactose hydrolysis during in vitro digestion. The optimal formulation was observed at a zein:pectin mass ratio of 3:2 and a pectin:CaCl2 mass ratio of 5:1 corresponding to an encapsulation efficiency of 93.0%, Z-average mean diameter of 652.7 nm, and the spherical capsules. The SDS-PAGE of the capsules showing protein bands corresponding to lactase and zein verified encapsulation of lactase. Zeta potential and H0 revealed the core-shell structure of the capsules. Electrostatic interactions, hydrophobic interactions, hydrogen bonding, and Ca2+ cross-linking between SBP molecules were responsible for nanoparticle formation based on turbidity and fluorescence intensity of dispersions as affected by sodium dodecyl sulfate, ethylenediaminetetraacetic acid, and urea. Capsules resulted in 33.1% and 40.0% lactose hydrolysis in whole and skim milk, respectively, at milk storage conditions. During in vitro digestion, encapsulated lactase resulted in 100 % and 89.4 % lactose hydrolysis in whole and skim milk, respectively, contrasting with negligible lactose hydrolysis by the same units of free lactase. Findings from this thesis suggest the potential of the studied capsules to incorporate lactase in milk, prevent lactose hydrolysis during storage, and hydrolyze lactose in milk during digestion