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.
Polymer films made from cellulose esters are useful for embedding plant essential oils, either for food packaging or air freshener applications. Studies and testing were done on the physical and ...mechanical properties of cellulose ester-based films incorporating essential oils (EO) from lemongrass (Cybopogon citratus), rosemary pepper (Lippia sidoides) and basil (Ocimum gratissimum) at concentrations of 10 and 20% (v/w). Results obtained showed that, in all films, the addition of the essential oil caused a decrease in the water vapor permeability due to the hydrophobic nature of the oil. The use of 20% of EO caused lower transparency of the films, although the change was not observed visually. Mechanical testing was done on cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate. It was found that incorporation of lemongrass, basil and rosemary pepper EO significantly affected the Young's modulus, tensile strength and elongation at break of the cellulose ester films. The results suggested that the essential oils interacted with the polymers like plasticizers. The results were confirmed with thermal and microscopic studies.
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).
Pequi oil has a high content of bioactive compounds identified in its composition, which gives it excellent potential for use in the food and pharmaceutical industries. Oil microencapsulation offers ...favorable conditions for storage and controlled release in order to maintain its functional characteristics for a longer time. In this study, vibration nozzle microencapsulation technology is applied to the production of pequi oil microparticles using sodium alginate. After encapsulation, the electrolytic complexation of the particles with chitosan is performed. The influence of frequencies (1500, 1800, 2000, 2500 Hz) on particle size and morphology is evaluated using the 120 µm nozzle. The microparticles formed at 1800 and 2000 Hz presented smaller size and greater sphericity, respectively. The formation of the electrolytic complex from alginate and chitosan is confirmed by FTIR analysis. Frequency adjustment is important for obtaining spherical and homogeneous particles. The encapsulation efficiency of pequi oil in alginate‐chitosan matrix is 96.17%. Electrolytic complexation of the alginate particles with chitosan can improve the reinforcement of the matrix and favor future application in the industry.
Pequi oil is rich in bioactive compounds which can be encapsulated to increase protection against extrinsic environmental factors. A delayed degradation of pequi oil may occur by using ...microencapsulation technology, in addition to masking unpleasant flavors and aromas. Complex coacervation is a technique based on the electrostatic interaction between two oppositely charged biopolymers which form a matrix complexed around an agent of interest. However, cross-linking the particles is often necessary in order to make them more rigid. The objective of this research was to produce and characterize pequi oil microparticles in a cashew gum (CG) and gelatin (GE) matrix cross-linked with tannic acid. Cross-linked pequi oil microparticles were produced by varying the concentrations of biopolymers (0.5% to 1.5%) and tannic acid (0.3% to 8.1%) using a rotational central compound design. Ratio of cashew gum, gelatin and oil was 2:1:1 (m/m/m);respectively, at pH 4.5. The cross-linking process was performed with tannic acid for 30 minutes at 40 °C. The optimized formulation by means of the rotational central compound design for microparticle formation was 0.65% biopolymers (CG and GE) and 6.9% tannic acid. Increasing the tannic acid percentage in the cross-linking of the pequi oil particles had a higher yield and encapsulation efficiency. Cross-linking provided an increase in the degradation temperature of material; and consequently, improved the thermal stability of the particles. The cross-linking process was advantageous in producing the microparticles.
RESUMO: O óleo de pequi é rico em compostos bioativos, os quais podem ser encapsulados para aumentar a proteção a fatores extrínsecos. A tecnologia de microencapsulamento, além de retardar a degradação do composto ativo, possibilita mascarar aromas e sabores indesejáveis. A coacervação complexa é uma técnica baseada na interação eletrostática entre dois biopolímeros com cargas opostas, que formam uma matriz complexada ao redor do agente de interesse. Entretanto, muitas vezes, se faz necessário o uso da reticulação para tornar as partículas mais rígidas. O objetivo deste trabalho foi produzir e caracterizar micropartículas de óleo de pequi em matriz de goma de cajueiro (GC) e gelatina (GE) reticulada com ácido tânico. As micropartículas de óleo de pequi reticuladas foram produzidas variando as concentrações de biopolímeros (0,5% a 1,5% m/v) e do ácido tânico, em relação à massa de biopolímeros (0,3% a 8,1% m/m), a partir de um delineamento de composto central rotacional. A proporção de GC, GE e óleo foi de 2:1:1 (m/m/m), respectivamente, em pH 4,5. O processo de reticulação foi realizado com ácido tânico por 30 minutos a 40 ºC. A formulação otimizada foi de 0,65% (m/v) de biopolímeros (GC e GE) e 6,9% (m/m) de ácido tânico. O aumento do percentual de ácido tânico na reticulação das partículas de óleo de pequi conferiu maior rendimento e eficiência de encapsulamento. A reticulação proporcionou aumento na temperatura de degradação do material, e consequente estabilidade térmica das partículas. O processo de reticulação foi vantajoso para a produção das micropartículas.
Acylation of polysaccharides is a commercially important reaction and is usually performed in a process involving the polysaccharide, an acid anhydride, and an inorganic acid. As an alternative to ...inorganic acid, many catalysts, including some metal chlorides, have been previously reported as catalysts. In this work, we took a more comprehensive look at several metal chlorides to observe trends and reactivities among them, particularly relating to reaction temperature, time, and amount of acetic anhydride used. Iodine was also included for comparison. Almost all the metal chlorides studied were found to be active as catalysts for the acetylation of starch under suitable reaction conditions. However, each metal chloride had a somewhat different reactivity with a different optimal temperature needed for satisfactory reactions to take place. The molecular weight of the starch acetate products decreased in all cases observed. The reactivity trends among the metal halides seemed to correlate both with the ease of complexation between the halide and the substrate and with the acidity of the metal chloride. Characterization was achieved through
13
C NMR, FT-IR, thermogravimetric analysis and size exclusion chromatography.
O desenvolvimento de novos métodos de análise microbiologica requer uma avaliaçao da igualdade ou superioridade deste em relaçao a um método padrao ouro - método rotineiramente utilizado. Este ...processo de avaliaçao denomina-se validaçao. O método é validado se seu desempenho estiver satisfatoriamente de acordo com os parâmetros analisados. Neste trabalho, abordamos os critérios para a validaçao de novos métodos de análise microbiológica da AOAC, FDA e da ISO 16140.
Optimized conditions of cashew gum (CG)/and chitosan (CT) were evaluated for the encapsulation of pequi oil by complex coacervation. A comparison was established with gum Arabic (GA)/CT. At first, ...the coacervation process without pequi oil was performed for determining the most appropriate proportion and pH for microparticle formation. The best conditions were of 22:1 at pH 4.5 for the CG/CT, and 6:1 at pH 3.5 for the GA/CT. Pequi oil release in a pH range was higher in pH 4.5 and 5 for GA/CT and CG/CT, respectively. Microparticle yield was about 60% for both complexes. The microparticle size was 4.8 and 2.7 µm for CG/CT and GA/CT, respectively. The encapsulation efficiency was 86 and 89% for CG/CT and GA/CT, respectively. CG forms an interesting complex with CT, 22:1 ratio at pH 4.5, for a suitable encapsulation of pequi oil.
Practical applications
Pequi oil has attractive anti‐inflammatory and antioxidant properties that could be used in the formulation of new cosmetics and nutraceuticals. The microencapsulation of pequi oil assists in the conservation of these properties because it avoids the direct exposure of the actives molecules to environmental factors and to the reagents and procedures involved in the preparation of a product. Complex coacervation method is recommended for the encapsulation of lipophilic substances and has the great advantage of not using high temperatures and being carried out in aqueous medium.
New functional foods and beverages can be developed using bioactive compounds present in pequi oil. Complex coacervation is an encapsulation method used for preserving bioactive molecules, especially ...those that are hydrophobic or sensitive to high temperatures. The objective of this work was to produce and characterize pequi oil microparticles using cashew gum/gelatin matrix (CG/GE) through complex coacervation. Gum Arabic (GA) was also studied in comparison with CG. The coacervation process was performed withoutpequi oil to determine the ideal proportions of the matrix components, followed by the embedding of the oil inthe microparticles for evaluation. Satisfactory microparticles were produced at pH 4.5 in the weight ratios of CG/GE = 2:1 and GA/GE = 1:3. Pequi oil release was greater in acidic pH, especially at pH 2 for the CG/GE matrix. The encapsulation efficiency for CG/GE and GA/GE was 72.53% (±4.80) and 82.77% (±6.09), respectively. The results showed that the CG/GE combination seemed very promising as anencapsulation matrix, especially for food applications involving pH values higher than 3.
Diabetes is a disease linked to pathologies, such as chronic inflammation, neuropathy, and pain. The synthesis by the Claisen−Schmidt condensation reaction aims to obtain medium to high yield ...chalconic derivatives. Studies for the synthesis of new chalcone molecules aim at the structural manipulation of aromatic rings, as well as the replacement of rings by heterocycles, and combination through chemical reactions of synthesized structures with other molecules, in order to enhance biological activity. A chalcone was synthesized and evaluated for its antinociceptive, anti-inflammatory and hypoglycemic effect in adult zebrafish. In addition to reducing nociceptive behavior, chalcone (40 mg/kg) reversed post-treatment-induced acute and chronic hyperglycemia and reduced carrageenan-induced abdominal edema in zebrafish. It also showed an inhibitory effect on NO production in J774A.1 cells. When compared with the control groups, the oxidative stress generated after chronic hyperglycemia and after induction of abdominal edema was significantly reduced by chalcone. Molecular docking simulations of chalcone with Cox -1, Cox-2, and TRPA1 channel enzymes were performed and indicated that chalcone has a higher affinity for the COX-1 enzyme and 4 interactions with the TRPA1 channel. Chalcone also showed good pharmacokinetic properties as assessed by ADMET.
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