Comparisons of simple and complex coacervations for preparation of sprayable insect sex pheromone microcapsules and release control of the encapsulated pheromone molecule

Abstract

With dodecanol (C12OH) as a model molecule of insect sex pheromone as core material, natural polymers gelatin (GE) and acacia gum (AG) as wall materials, microcapsules aiming to be a sprayable environment-friendly pesticide were prepared via GE simple coacervation and complex coacervation of GE and AG. C12OH encapsulation in complex coacervation was higher than those in simple coacervation. Its encapsulation was enhanced with increase in wall material cross-linking. C12OH release revealed that samples from simple coacervation reached their end in 7 days, whereas those from complex coacervation manifested a quick release followed by a constant release. With increase in wall material cross-linking, the release was slowed down. SEM observation confirmed that core-shell morphology existed in the capsules.

Preparation of safflower oil microcapsules with gelatin and a novel exopolysaccharide as wall matrix

“…As shown in Figure a, a content of TG in microencapsulation technology influenced encapsulation efficiency, cross‐linking degree between gelatin and exopolysaccharide was weak with a small amount of TG and molecules of gelatin and exopolysaccharide entered the water phase again (Gu et al, ). Low TG concentration resulted in lower enzymatic activity, and thus lower microcapsule cross‐linking degree.…”

“…After hardening time of 120 min, the microcapsule suspension was filtered using quantitative papers (one membrane) by vacuum filtration and rinsed with deionized water. Then wet microcapsules were obtained in a freezing thermostat by temperature control during the whole cross‐linking process (Gu, Zhu, Kong, & Tan, ). The cross‐linked microcapsules were subjected to Freeze‐dry (Heto dry winner, Denmark) for 8 hr and the encapsulation efficiency of the microcapsules was determined.…”

A review of the preparation and application of flavour and essential oils microcapsules based on complex coacervation technology

“…The GE–GA pair is the classical system for complex coacervation and the GE–GA system has been studied using several flavour and essential oils as core materials, such as allyl isothiocyanate, limonene, medium‐chain triglycerides, menthol, violet, lemon and peach perfumes, dodecanol, flavour oil, peppermint oil, jasmine oil, lemon oil, citronella oil, vetiver oil, garlic oil, turmeric oleormeric, patchouli oil etc . (Table ).…”

“…This process can be disrupted or stopped if the release of pheromones is disrupted and this may be useful in the control of infestation or for insect monitoring . Microencapsulation of insect sex pheromones such as dodecanol, dodecyl acetate and α ‐pinene by complex coacervation to disrupt their mating process is a new technology, and new types of pesticides with microcapsules tailored to control the rate of release of the pheromone fill and also protect the pheromone from oxidation and light during storage and release. The technology has been applied to produce pesticides that are environmentally friendly, with a low toxicity or are toxicity‐free, and can be used in agricultural and forestry to control pest infestation.…”

Microcapsuled entomopathogenic fungus against fire ants, Solenopsis invicta

“…Microencapsulation methods have been extensively applied to improve pesticides, foods, enzymes, bait pheromones, where wall materials applied in a micrometric scale can effectively improve the stability of bio-active substances, as well as regulate their release (Eratte et al, 2014, Gu et al, 2010, Leefong and Cheesian, 2013, Opender Koul, 2011.…”