scholarly journals Preparation methods and release kinetics of Litsea cubeba essential oil microcapsules

RSC Advances ◽  
2018 ◽  
Vol 8 (52) ◽  
pp. 29980-29987 ◽  
Author(s):  
Yan-hong Yang ◽  
Xiang-zhou Li ◽  
Sheng Zhang

LCEO microcapsules were prepared by various preparation methods such as grinding, saturated solution, freeze-drying, spray-drying with β-CD used as the wall material. Avrami's model was used to simulate the release rates of microcapsules.

2022 ◽  
Vol 125 ◽  
pp. 107430
Author(s):  
Jelena Bajac ◽  
Branislava Nikolovski ◽  
Ivana Lončarević ◽  
Jovana Petrović ◽  
Branimir Bajac ◽  
...  

2008 ◽  
Vol 32 (2) ◽  
pp. 533-540 ◽  
Author(s):  
Vladimir Antônio Silva ◽  
Giuliano Marchi ◽  
Luiz Roberto Guimarães Guilherme ◽  
José Maria de Lima ◽  
Francisco Dias Nogueira ◽  
...  

Kinetic studies on soil potassium release can contribute to a better understanding of K availability to plants. This study was conducted to evaluate K release rates from the whole soil, clay, silt, and sand fractions of B-horizon samples of a basalt-derived Oxisol and a sienite-derived Ultisol, both representative soils from coffee regions of Minas Gerais State, Brazil. Potassium was extracted from each fraction after eight different shaking time periods (0-665 h) with either 0.001 mol L-1 citrate or oxalate at a 1:10 solid:solution ratio. First-order, Elovich, zero-order, and parabolic diffusion equations were used to parameterize the time dependence of K release. For the Oxisol, the first-order equation fitted best to the experimental data of K release, with similar rates for all fractions and independent of the presence of citrate or oxalate in the extractant solution. For all studied Ultisol fractions, in which K release rates increased when extractions were performed with citrate solution, the Elovich model described K release kinetics most adequately. The highest potassium release rate of the Ultisol silt fraction was probably due to the transference of "non-exchangeable" K to the extractant solution, whereas in the Oxisol exchangeable potassium represented the main K source in all studied fractions.


Author(s):  
Gabriel Ribeiro Carvalho ◽  
Amanda Maria Teixeira Lago ◽  
Maria Cecília Evangelista Vasconcelos Schiassi ◽  
Priscila de Castro e Silva ◽  
Soraia Vilela Borges ◽  
...  

Abstract The objective of this work was to evaluate the partial replacement of gum arabic by modified starches on the spray-drying microencapsulation of lemongrass (Cymbopogon flexuosus) essential oil. The ultrasound-assisted emulsions were prepared with 30% (w/w) of wall material, 7.5% (w/w) of oil load, and 1:1 (w/w) replacement ratio for all treatments. After 16 hours, the incompatibility observed between gum arabic and octenyl succinic anhydride (OSA) starch did not affect the obtained microparticles, since the treatment with OSA starch, partially replacing gum arabic, showed the best results for the process yield and for the oil charge retention after spray-drying process, and the treatment showed Newtonian viscosity close to that of the treatment prepared with gum arabic. Maltodextrin dextrose equivalent 10 (10DE) shows an oil load similar to that of the treatment with gum arabic, while the presence of maize maltodextrin DE20 reduces the content of encapsulated oil and the efficiency of the drying process due to the adherence of particles to the chamber. Therefore, the partial substitution of gum arabic is an alternative for the formation of emulsions, for the spray-drying microencapsulation of lemongrass essential oil.


2020 ◽  
Vol 3 (4) ◽  
pp. 60-67
Author(s):  
Jessica Alarcón-Moyano ◽  
◽  
Silvia Matiacevich ◽  

The use of bioactive/active additives has been increasing in recent years, especially those derived from medicinal plants such as essential oils. However, due to essential oil oxidation it is necessary to protect it by encapsulation techniques such as: emulsion, spray- and/or freeze-drying as the most economical techniques. On the other hand, an important factor is to determine the appropriate wall material to obtain a prolonged or controlled release in the food or in the organism. Therefore, several factors affect the release of the compounds such as the type, amount of wall material and/or combination of wall materials. Therefore, the knowledge of all the aforementioned factors is important in order to make an adequate selection for the development of a bioactive/active additive based on essential oils.


2019 ◽  
Vol 11 (2) ◽  
pp. 529-542 ◽  
Author(s):  
Lorenna Fonseca ◽  
Marcio dos S. Rocha ◽  
Larisse C. F. Brito ◽  
Edymilaís S. Sousa ◽  
Fernanda S. Reinaldo ◽  
...  

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Takashi Sasaki ◽  
Kazuki Tanaka ◽  
Daisuke Morino ◽  
Kensuke Sakurai

Freeze-drying a biodegradable polymer, poly(L-lactic acid) (PLLA), from 1,4-dioxane solutions provided very porous spherical particles of ca. 3 mm in radius with specific surface area of 8–13 m2 g−1. The surface of the particle was found to be less porous compared with its interior. To apply the freeze-dried PLLA (FDPLLA) to drug delivery system, its morphology and drug releasing kinetics were investigated, bovine serum albumin (BSA) being used as a model drug compound. Immersion of FDPLLA into a BSA aqueous solution gave BSA-loaded FDPLLA, where mass fraction of the adsorbed BSA reached up to 79%. Time-dependent release profile of BSA in water suggested a two-step mechanism: (1) very rapid release of BSA deposited on and near the particle surface, which results in an initial burst, and (2) leaching of BSA from the interior of the particle by the diffusion process. It was suggested that the latter process is largely governed by the surface porosity. The porosity of both the interior and surface was found to decrease remarkably as the concentration of the original PLLA/1,4-dioxane solution increases, C0. Thus, C0 is a key parameter that controls the loading and releasing of BSA.


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