Search

Considerable efforts have been spent on the development of biodefensives based on the encapsulation of essential oils for controlling of urban pests from their larval stage, especially as anopheline controlling agents. The larval source management of Anopheles aquasalis is important for malaria prevention. For this reason, this research proposes larvicidal biodefensives based on polymeric particles loaded with Piper nigrum essential oil, considering the influence of temperature (35 °C) and preservatives on the formulation stability. The biodefensive containing the preservative phenoxyethanol/methylisothiazolinone (PNE) resulted in 5 months of shelf-life storage with an Encapsulation Efficiency (EE%) of essential oil of 70%. The biodefensive PNE (containing 500 µg.mL -1 of encapsulated essential oil) presented a polydisperse particle size distribution, ranging from D 10 = (127 ± 10) nm to D 90 = (472 ± 78) nm and a particle mean size of (236 ± 34) nm. The AFM images revealed a spherical morphology with an external surface almost regular and smooth. The controlled release of the essential oil was evaluated up to 72 h according to the Korsmeyer-Peppas mathematical model, confirming the anomalous transport ( n = 0.64 in pH = 3 and pH = 10, and n = 0.65 in pH = 7). The total larvae mortality on the in loco bioassays was almost reached (92%) after 24 h. However, according to the in vitro bioassays applying the in natura essential oil alone, the concentration of 454 μg.mL -1 resulted on the mortality of 70% of the larvae after 24 h. For this reason, the highest efficiency of the biodefensive PNE may be related to the encapsulation of essential oil, delivering the loaded particles more efficiently inside the larvae. From this perspective, the present study shows that a formulation based on P. nigrum essential oil may be taken into account in the integrated management of disease vector mosquitoes.

Background: The encapsulated essential oils (EOs) of Piper aduncum L. and Piper hispidinervum C. DC. in gelatin nanoparticles were evaluated against Aedes aegypti Linn., Tetranychus urticae Koch and Cerataphis lataniae Boisd., Results: Encapsulation efficiency of the EOs was measured for absolute concentrations of 500 µg mL -1 (79.2 and 72.7%) and 1000 µg mL -1 (84.5 and 82.2%). The loaded nanoparticles were nearly spherical and well dispersed. The nanoparticles loaded with P. hispidinervum EO had an average size of 100 ± 2 nm, while the nanoparticles containing P. aduncum EO ranged from 175 ± 4 to 220 ± 4 nm. According to zeta potential analysis, the nanoparticles loaded with P. hispidinervum and P. aduncum EOs presented values around -43.5 ± 3 and -37.5 ± 2 mV respectively. The controlled release of EOs was described by the anomalous mechanism of Korsmeyer-Peppas. Both encapsulated EOs reached lethal dosages within 24 h of exposure and total mortality of the tested pests., Conclusion: The present work successfully developed gelatin-based nanoparticles that served as carriers for the EOs of P. aduncum and P. hispidinervum to be applied as a sustainable control tool of A. aegypti, T. urticae and C. lataniae. The developed loaded nanoparticles presented high encapsulation efficiency and EO concentration release higher than lethal dosages. This indicates that it is feasible to use gelatin-based nanoparticles loaded with P. aduncum and P. hispidinervum EOs to control the tested pests. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

The objective of this work was to analyze the influence of maltodextrin equivalent dextrose on the lime essential oil reconstitution, storage, release and protection properties. Four treatments were evaluated: whey protein concentrate (WPC), and blends of maltodextrin with dextrose equivalents of 5 (WM5), 10 (WM10) and 20 (WM20). The reconstitution and storage properties of the microparticles (solubility, wettability and density), water kinetics adsorption, sorption isotherms, thermogravimetric properties, controlled release and degradation kinetics of encapsulated lime essential oil were studied to measure the quality of the encapsulated materials. The results of the study indicated that the DE degree influences the characteristics of reconstitution, storage, controlled release and degradation characteristics of encapsulated bioactive compounds. The increase in dextrose equivalent improves microparticle solubility, wettability and density, mainly due to the size of the maltodextrin molecules. The adsorption kinetics and sorption isotherm curves confirmed the increase in the hygroscopicity of maltodextrins with higher degrees of polymerization. The size of the maltodextrin chains influenced the release and protection of the encapsulated lime essential oil. Finally, the maltodextrin polymerization degree can be considered a parameter that will influence the physicochemical properties of microencapsulated food., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The aim of this work was to study the use of different prebiotic biopolymers in lime essential oil microencapsulation. Whey protein isolate, inulin and oligofructose biopolymers were used. The addition of prebiotic biopolymers reduced emulsion viscosity, although it produced larger droplet sizes (0.31-0.32 µm). Moisture values (2.94-3.13 g/100 g dry solids) and water activity (0.152-0.185) were satisfactory, being within the appropriate range for powdered food quality. Total oil content, limonene retention values and antioxidant activity of the microparticles containing essential oil decreased in the presence of the carbohydrates. The addition of prebiotic biopolymers reduced the microparticle thermal stability. X-ray diffraction confirmed the amorphous characteristic of the microparticles and the interaction of the essential oil with the wall material. The presence of prebiotic biopolymers can be a good alternative for lime essential oil microparticles, mainly using fibre that has a functional food appeal and can improve consumer health.