Kratki pregled metoda mikroinkapsulacije biljnih ulja: principi, stabilnost i primjena

In addition to being used in food, fuel and lubricants, vegetable oils are promising in many other applications such as food additives, nutritional supplements, cosmetics and biomedicine; however, their low oxidative stability can limit their use. Microencapsulation is a well-established method for the preservation of oil against degradation, controlled release of active ingredients, protection against external factors during storage, and enhanced durability. In this article, microencapsulation methods for vegetable oil are reviewed, including physical methods (spray-drying and freeze-drying), physicochemical methods (complex coacervation, ionic gelation and electrostatic layer-by-layer deposition), and chemical methods (interfacial/in situ polymerization). This article also provides information on the principles, parameters, advantages, disadvantages and applications of these methods.Biljna ulja se osim u prehrani te kao goriva i maziva, mogu koristiti kao dodaci hrani, nutraceutici, u proizvodnji kozmetike i biomedicini, no primjena im je ograničena zbog slabe oksidacijske stabilnosti. Mikroinkapsulacija je uobičajena metoda zaštite ulja od razgradnje i vanjskih čimbenika tijekom skladištenja, kojom se kontrolira otpuštanje aktivnih sastojaka i produljuje trajnost ulja. U ovom je radu dan kratki pregled metoda mikroinkapsulacije biljnih ulja, uključujući fizikalne (sušenje raspršivanjem i zamrzavanjem), fizikalno-kemijske (kompleksna koacervacija, ionsko geliranje i slojeviti elektrostatski premazi) i kemijske (međufazna i in situ polimerizacija) postupke. Osim toga, ovaj rad donosi informacije o principima, parametrima, prednostima i nedostacima, te mogućim primjenama ovih metoda

FILMES DE POLIANILINA (PANI) ELETROPOLIMERIZADOS SOBRE SUPERFÍCIE DE ITO PARA USO COMO INDICADOR COLORIMÉTRICO PARA DETECÇÃO DA AMÔNIA: POLIMERIZAÇÃO DE FILMES DE PANI COMO INDICADOR DA PRESENÇA DE AMÕNIA

Indicadores colorimétricos são sistemas que podem facilmente ser introduzidos a embalagens, a fim de informar ao consumidor a cerca da qualidade do produto. Amônia é gerada durante a deterioração do pescado e pode ser monitorada por meio de indicadores colorimétricos. Neste trabalho objetivou-se eletrossintetizar filmes de polianilina para a detecção da amônia por meio da mudança de cor. Filmes foram eletrodepositados por voltametria cíclica e cronoamperometria em meio ácido sobre superfície de ITO. O filme crescido por voltametria cíclica apresentou uma morfologia mais plana e um limite de detecção de 0,05 mol L-1. O filme crescido por cronoamperometria apresentou uma morfologia de rede interconectada, um limite de detecção de 0,015 mol L−1 e uma mudança de cor verde para azul mais perceptível visualmente. Assim, recomenda-se produzir o filme por cronoamperometria para a produção de um indicador colorimétrico para detecção da amônia em função do limite de detecção e da melhor visualização da mudança de coloração

ANÁLISE TERMOGRAVIMÉTRICA DE MICROPARTÍCULAS DE ÓLEO DE PEQUI (CARYOCAR CORIACEUM WITTM.) EM MATRIZ POLIMÉRICA DE ALGINATO E QUITOSANA

Pequi oil has high level of antioxidant substances, phenolic compounds, vitamin A and E, substances that are sensitive to the presence of light and oxygen. In order to provide greater stability to these compounds, microencapsulation techniques have been applied. Microparticles have different characteristics depending on the matrix, the microencapsulation technique and the drying method used. Thermal stability of the resulting microparticles is always important for industrial applications. The objective of this work was to perform thermogravimetric analysis (TGA) of pequi oil microparticles (OP) with chitosan (QT) / alginate (AG) and alginate matrixes submitted to oven drying and freeze drying. The percentage weight loss was calculated over time. The QT/ AG/OP microcapsules showed a higher temperature and enthalpy of degradation than AG/OP, thus the electrolytic complexation of QT/AG resulted in better thermal stability. Regardless of the drying method applied, the QT/ AG/OP particles showed the first degradation peak at 375 ° C, thus this matrix was suitable for oil protection in terms of thermal resistance.Óleo de pequi apresenta em sua constituição altos teores de substâncias antioxidantes, compostos fenólicos, vitamina A e E, substâncias essas sensíveis a presença de luz e oxigênio. A fim de proporcionar maior estabilidade a esses compostos, as técnicas de microencapsulação vêm sendo aplicadas. Micropartículas apresentam diferentes características a depender da matriz, da técnica de microencapsulação e do método de secagem utilizados. Estabilidade térmica das micropartículas resultantes é sempre importante para aplicações a nível industrial. O objetivo desse trabalho foi realizar análise termogravimétrica (TGA) de micropartículas de óleo de pequi (OP) com matrizes de quitosana (QT)/ alginato (AG) e de alginato submetidas as secagens em estufa e por liofilização. A perda de massa percentual foi calculada em relação ao tempo. As microcápsulas de QT/AG/OP apresentaram maior temperatura e entalpia de degradação do que AG/OP, podendo inferir assim que a complexação eletrolítica de QT/AG resultou em melhor estabilidade térmica. Independentemente do método de secagem aplicado, as partículas de QT/AG/OP apresentaram o primeiro pico de degradação em 375 °C, sendo esta matriz de polissacarídeo adequada para a proteção do óleo em termos de resistência térmica

Use of cashew gum combined with galactomannan for encapsulation of Rosmarinus officinalis essential oil

Encapsulating matrices are important to maintain the properties, promote the low and controlled release, and avoid these bioactive compounds' undesirable reactions. This study's objective was to evaluate cashew gum (CG) use combined with galactomannan (GAL) in the rosemary essential oil encapsulation by atomization. During the emulsification, the polysaccharides were crosslinked with sodium trimetaphosphate. The particles obtained after encapsulation were evaluated for moisture, solubility, particle size, encapsulation efficiency, morphology, antimicrobial activity, and chemical composition of the essential oil volatiles. GAL/CG blend showed higher encapsulation efficiency and lower oil release than the cashew gum matrix. Undoubtedly, galactomannan combined with cashew gum improved the microparticles' characteristics due to the galactomannan's high emulsifying property even in low concentration. Essential oil maintained its antimicrobial and chemical properties practically after the encapsulation procedure

To cultivate of herbaceous cotton plant submitted to the natural infestation of plagues

As cultivares de algodoeiro apresentam caracterÃsticas morfolÃgicas e quÃmicas diferentes que podem influenciar a susceptibilidade Ãs pragas. Neste contexto, esse trabalho teve o objetivo de comparar a suscetibilidade das cultivares de algodoeiro herbÃceo BRS Antares, BRS 201, BRS Facual, BRS IpÃ, BRS ITA 96 BRS Sucupira, CNPA 8H, CNPA ITA 90, CNPA Precoce 3 e DeltaOpal Ãs pragas agrÃcolas, nas condiÃÃes de Fortaleza, CE. No experimento em campo, o delineamento experimental utilizado foi o de blocos casualizados, com trÃs repetiÃÃes para as plantas submetidas à infestaÃÃo natural e uma repetiÃÃo para as plantas com controle da infestaÃÃo. Cada parcela constituiu-se de trÃs linhas de trÃs metros, sendo a Ãrea Ãtil composta somente da linha central constituÃda por treze plantas. Para o monitoramento das pragas fez-se a cada sete dias observaÃÃes em campo. Na InfestaÃÃo por cochonilha (Planococcus sp.) e pulgÃo (Aphis gossypii) anotou-se o nÃmero de plantas infestadas quando essas apresentavam pelo menos uma colÃnia da espÃcie. Para o ataque de besouro-creme (Costalimaita ferruginea) anotou-se o nÃmero de plantas que apresentavam dano ≥ 10% do nÃmero total de folhas. Na infestaÃÃo por lagarta-rosada (Pectinophora gossypiella) anotou-se o nÃmero de plantas atacadas. Foram consideradas as seguintes caracterÃsticas agronÃmicas: (a) altura de inserÃÃo do primeiro ramo frutÃfero, (b) nÃmero de nÃs atà o primeiro ramo frutÃfero, (c) altura de plantas, (d) nÃmero de ramos frutÃferos por planta, (e) nÃmero de capulhos por planta, (f) dias para abertura da primeira flor, (g) dias para abertura do primeiro capulho, (h) peso mÃdio do capulho, (i) percentagem de fibra, (j) peso de 100 sementes, (l) precocidade da colheita e (m) produÃÃo. No experimento de casa-de-vegetaÃÃo, plantas das dez cultivares foram infestadas apÃs dezesseis dias de germinaÃÃo com cinco pulgÃes adultos. A contagem do nÃmero de adultos/planta foi realizada apÃs vinte e quatro horas de infestaÃÃo e a segunda avaliaÃÃo referente ao nÃmero de ninfas e de adultos/planta foi feita decorridos seis dias da instalaÃÃo do experimento. O delineamento experimental utilizado foi o inteiramente casualizado com dez tratamentos e seis repetiÃÃes. As pragas cochonilha, pulgÃo e besouro-creme nÃo demonstraram diferenÃa na preferÃncia das cultivares. A infestaÃÃo pela lagarta-rosada foi maior nas cultivares: BRS Antares, CNPA Precoce 3 e DeltaOpal. Foram encontradas reduÃÃes significativas em relaÃÃo ao controle para as seguintes caracterÃsticas: altura de inserÃÃo do primeiro ramo frutÃfero, altura das plantas, produÃÃo, precocidade e peso mÃdio dos capulhos. Considerando a infestaÃÃo das pragas e o rendimento de fibra na produÃÃo total entre as plantas infestadas, verificou-se que a cultivar CNPA Precoce 3 e CNPA ITA 90 apresentaram valores inferior e superior Ãs outras cultivares, respectivamente. Na infestaÃÃo artificial feita com os pulgÃes, nÃo houve diferenÃa significativa entre as cultivares, as quais apresentaram em mÃdia 4,06 adultos apÃs 24 horas de infestaÃÃo, 7,76 e 62,91 ninfas e adultos apÃs seis dias de infestaÃÃo, respectivamente. Pode-se concluir que a CNPA ITA 90 foi a cultivar com melhor desempenho nesta pesquisa em frente à susceptibilidade Ãs pragas.The cotton cultivars have different morphological and chemical characteristics that may influence the susceptibility of the plants to pests. The objective of this work was to compare the susceptibility of the Upland cotton cultivars BRS Antares, BRS 201, BRS Facual, BRS IpÃ, BRS ITA 96, BRS Sucupira, CNPA 8 H, CNPA ITA 90, CNPA Precoce 3 and DeltaOpal to agricultural pests in the conditions of Fortaleza-CearÃ, Brazil. In field tests, the experimental design was a completely randomized block with three replications for the plants submitted to natural infestation and one repetition for the plants with control of the infestation. Each experimental unit had three rows with three meters long. The area observation was composed by the central row with thirteen plants. The evaluations of the infestations were made across observations in the field ever each seven days. The number of plants infested by mealybug (Planococcus sp.) and aphid (Aphis gossypii) was recorded each seven days when the plants had at least one colony of the species. The number of plants infested by yellow beetle (Costalimaita ferruginea) was recorded when the plants had at least 10% or more leaves damaged. In the infestation for pink bollworm (Pectinophora gossypiella) it was recorded the number of attacked plants. The following agronomic characteristics were considered: (a) first fruiting branch height, (b) number of nodes for the first fruiting branch, (c) plant height, (d) number of fruiting branches/plant, (e) number of boll/plant, (f) days of first flower open, (g) days of first boll open, (h) average of boll weight, (i) fiber percentage, (j) 100 seeds weight, (l) earliness and (m) yield. In greenhouse test, the plants of the ten cultivars were infested with six adult aphids after six days of germination. The number of adults/plant was recorded twenty four hours after infestation and the number of ninphs and adults/plant was also recorded six days after beginning of the experiment. The experimental design was a completely randomized with six replication of each cultivar. There were no significant differences among the cultivars damaged by Planococcus sp, A. gossypii, C. ferruginea. The cultivars BRS Antares, CNPA Precoce 3 and DeltaOpal were more infested by P. gossypiella than the other cultivars. There were significant differences among infested plants and control plants for the following characters: first fruiting branch height, plant height, earliness, yield and average of boll weight. CNPA Precoce 3 yielded less fibers and CNPA ITA 90 had the highest fiber yield. The greenhouse results indicated that there were no significant differences among the cultivars which showed an average of 4,06 adults twenty four hours after infestation and also 7,76 and 62,91 ninphs and adults respectively, six days after the infestation. CNPA ITA 90 cultivar was the one with smaller susceptibility to pests

Polymeric Composite including Magnetite Nanoparticles for Hydrogen Peroxide Detection

The combination of a biopolymer and a conductive polymer can produce new materials with improved physico-chemical and morphological properties that enhance their use as sensors. Magnetite nanoparticles (MN) can be further introduced to these new matrices to improve the analytical performance. This study aimed to evaluate the electrocatalytic response of nanocomposites formed by the introduction of MN to polypyrrole (PPy) doped in the presence of cashew gum polysaccharide (CGP) and in the presence of carboxymethylated cashew gum polysaccharide (CCGP). Characterization of the nanocomposites was carried out via transmission electron microscopy (TEM) and infrared spectroscopy (FTIR) and showed that the absorption band of the blend was shifted to a higher frequency in the nanocomposites, indicating the intermolecular interaction between the blend and nanoparticles. The electrocatalytic performance of the nanocomposites was evaluated by applying a constant potential of −0.7 V with successive additions of H2O2 (1 mmol L−1) in 10 mmol L−1 phosphate buffer under agitation at pH 7.5. The nanocomposite formed by the introduction of MN to polypyrrole doped with cashew gum polysaccharide (PPy(cgp)–MN) displayed excellent electrocatalytic surface properties, with high H2O2 specificity, a linear response (R2 = 0.99), high sensitivity (0.28 µmol L−1), and a low H2O2 detection limit (0.072 mmol L−1)

Evaluation of the Properties of Cellulose Ester Films that Incorporate Essential Oils

Films made from cellulose esters are often used as bio-based food packaging materials. In this work, we studied the incorporation of nine essential oils into cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate. The essential oils were derived from lime, nutmeg, eugenol, pimenta berry, rosemary, petitgrain, coffee, anise, and trans-cinnamaldehyde. In almost all cases, the addition of essential oils to cellulose ester reduced tensile strength and Young’s modulus but increased elongation at break. Thus, an essential oil acted like a plasticizer that enhanced the flexibility of the polymer. Essential oils containing limonene and pinenes (e.g., from lime and nutmeg) gave the strongest plasticizing action, whereas essentials oils containing fatty acids (e.g., from coffee) were the weakest plasticizers. The water barrier property was improved the most when essential oils were added to cellulose acetate; however, different cellulose ester/essential oil combinations showed different effects. Whereas most of the essential oils decreased the transparency of the films, eugenol, pimento berry, and anise were notable exceptions. Thus, depending on a specific application, a particular polymer/EO combination can be used to give the optimal performance

Effect of different polysaccharides and crosslinkers on echium oil microcapsules

Microencapsulation by complex coacervation using gelatin and arabic gum (AG) as wall materials and transglutaminase for crosslinking is commonly used. However, AG is only produced in a few countries and transglutaminase is expensive. This work aimed to evaluate the encapsulation of echium oil by complex coacervation using gelatin and cashew gum (CG) as wall materials and sinapic acid (S) as crosslinker. Treatments were analyzed in relation to morphology, particle size, circularity, accelerated oxidation and submitted to different stress conditions. Rounded microcapsules were obtained for treatments with AG (45.45 μm) and microcapsules of undefined format were obtained for treatments with CG (22.06 μm). The S incorporation for 12 h improved the oil stability by three fold compared to oil encapsulated without crosslinkers. Treatments with CG and S were resistant to different stress conditions similar to treatments with AG and transglutaminase, making this an alternative for delivery/application of compounds in food products.The authors thank Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) for the scholarship for T.A. Comunian (Process 2013/25862-5) and for financial support (Process 2012/08058-5) and De Wit Speciality Oils for the echium oil donation. C.S. Favaro-Trindade thanks Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the productivity grant (306708/2015-9)Peer Reviewe

Produção de anticorpos policlonais anti-ricina Production of polyclonal anti-ricin antibodies

A ricina é uma proteína bastante tóxica presente nas sementes de mamona que impossibilita o uso da torta de mamona "in natura", como ração. A torta de mamona destoxificada necessita ainda de métodos de análise que garantam a ausência de traços dessa proteína. Objetivou-se, neste trabalho, produzir e avaliar a sensibilidade e especificidade de anticorpos policlonais anti-ricina, para serem empregados como possíveis componentes de métodos sorológicos na detecção de ricina em torta de mamona destoxificada. Foram avaliadas três doses da proteína: 400, 180 e 100 µg cada uma dividida em duas aplicações em coelhos. A primeira dose foi injetada no animal no início do experimento e a segunda após 21 dias. O método de ELISA indicou que as duas doses menores (100 e 180 µg) induziram respostas imunológicas primária e secundária com produção de anticorpos específicos. Enquanto a dose maior (400 µg) de ricina apresentou uma resposta primária com elevação dos títulos de anticorpos, seguida de uma supressão da resposta. Esse perfil é sugestivo de tolerância imunológica. Pela técnica de Western blotting verificou-se que os anticorpos policlonais produzidos são bastante específicos para a ricina, no entanto, por detectarem ricina na forma nativa e desnaturada não são recomendados para o monitoramento de ricina em torta de mamona destoxificada por tratamento térmico.Ricin is a very toxic protein found in castor bean plants, making it impossible to use natural castor cake as animal food. The detoxificated castor cake needs to be analyzed by methods that ensure the absence of traces of this protein. This work had the objective to produce and to evaluate the sensitivity and specificity of anti-ricin polyclonal antibodies, to be employed as component of sorologic methods as the ELISA in the detection of ricin in detoxificated castor cake. Three doses of protein, 400, 180 and 100 µg were evaluated each one injected twice into rabbit, with one half in the begin of the experiment and the other half after 21 days of immunization. The ELISA method indicated that the lower doses (100 e 180 µg) induced primary and secondary immunological response with production of specific antibodies, while the higher dose of ricin (400 µg) showed a primary response with increase of the antibody titre, followed of immunological suppression. This profile suggests immunological tolerance. By Western blotting technique it was verified that polyclonal antibodies are too specific to ricin, however, they detected ricin in native and denaturated form and are not recommended for the monitoring of ricin in detoxificated castor bean cake by heat treatment