Preparation and release mechanism of lavender oil microcapsules with different combinations of coating materials

Microencapsulation by Complex Coacervation of Lavender Oil Obtained by Steam Distillation at Semi-Industrial Scale

Lavender oil (LEO) is one of the most well-known essential oils worldwide which, besides its extensive application in aromatherapy, serves as raw material for various fields, including the food, cosmetic, and pharmaceutical industries. Accordingly, several global requirements were established to warrant its quality. Microencapsulation represents an emerging technology widely applied for the preservation of essential oils, simultaneously providing new ways of application. In the current study, lavender oil was obtained from the flowering tops of Lavandula angustifolia Mill. on a semi-industrial-scale steam distillation system. According to the GC-MS investigation, lavender oil obtained in the third year of cultivation met the European Pharmacopoeia standards for linalyl acetate and linalool contents ≈38% and ≈26%, respectively. Microcapsules (MCs) containing the so-obtained essential oil were successfully produced by complex coacervation technology between gum arabic (GA) and three different grades of type-A gelatin (GE). Optical microscopic investigations revealed a significant difference in particle size depending on the gelatin grade used. The variation observed for coacervates was well reflected on the scanning electron micrographs of the freeze-dried form. The highest encapsulation efficiency values were obtained by UV-VIS spectrophotometry for microcapsules produced using gelatin with the medium gel strength. FT-IR spectra confirmed the structural modifications attributed to microencapsulation. According to the GC-MS analysis of the freeze-dried form, the characteristic components of lavender oil were present in the composition of the encapsulated essential oil.

Recent developments in the encapsulation of lavender essential oil

The unregulated and extensive application of synthetic compounds, such as preservatives, pesticides, and drugs, poses serious concerns to the environment, food security, and global health. Essential oils (EOs) are valid alternatives to these synthetic chemicals due to their therapeutic, antioxidant, and antimicrobial activities. Lavender essential oil (LEO) can be potentially applied in food, cosmetic, textile, agricultural, and pharmaceutical industries. However, its bioactivity can be compromised by its poor stability and solubility, which severely restrict its industrial applications. Encapsulation techniques can improve the functionality of LEO and preserve its bioactivity during storage. This review reports recent advances in the encapsulation of LEO by different methods, such as liposomes, emulsification, spray drying, complex coacervation, inclusion complexation, and electrospinning. It also outlines the effects of different processing conditions and carriers on the stability, physicochemical properties, and release behavior of encapsulated LEO. Moreover, this review focuses on the applications of encapsulated LEO in different food and non-food products.

Quercetin directed transformation of calcium carbonate into porous calcite and their application as delivery system for future foods

The hierarchically porous property of CaCO3 has attracted considerable attention in the field of active delivery ingredients due to its high adsorption capacity. Here, a facile and high-efficient approach to control the calcification processes of CaCO3 ending with calcite microparticles with superior porosity and stability is reported and evaluated. In this work, a series of quercetin promoted CaCO3 microparticles, using soy protein isolate (SPI) as entrapment agent, was synthesized, characterized, and their digestive behavior and antibacterial activity were evaluated. Results obtained indicated that quercetin showed good ability to direct the calcification pathway of amorphous calcium carbonate (ACC) with the formation of flower- and petal-like structures. The quercetin-loaded CaCO3 microparticles (QCM) had a macro-meso-micropore structure, which was identified to be the calcite form. The macro-meso-micropore structure provided QCM with the largest surface area of 78.984 m2g-1. The loading ratio of SPI to QCM was up to 200.94 μg per mg of QCM. The protein and quercetin composite microparticles (PQM) were produced by simply dissolving the CaCO3 core, and the obtained PQM was used for the delivery of quercetin and protein. Thermogravimetric analysis showed PQM presented with good thermal stability without the CaCO3 core. Furthermore, minor discrepancy was noted in protein conformational structures after removing the CaCO3 core. In vitro digestion revealed that approximately 80% of the loaded quercetin was released from PQM during intestinal digestion, and the released quercetin exhibited efficient transportation across the Caco-2 cell monolayer. More importantly, the PQM digesta retained enhanced antibacterial activities to inhibit growth of Escherichia coli and Staphylococcus aureus. Porous calcites show a high potential as a delivery system for food applications.

Preparation of aromatic β-cyclodextrin nano/microcapsules and corresponding aromatic textiles: A review

Fragrance finishing of textiles is receiving substantial interest, with aromatherapy being one of the most popular aspects of personal health care. However, the longevity of aroma on textiles and presence after subsequent launderings are major concerns for aromatic textiles directly loaded with essential oils. These drawbacks can be weakened by incorporating essential oil-complexed β-cyclodextrins (β-CDs) onto various textiles. This article reviews various preparation methods of aromatic β-cyclodextrin nano/microcapsules, as well as a wide variety of methods for the preparation of aromatic textiles based on them before and after forming, proposing future trends in preparation processes. The review also covers the complexation of β-CDs with essential oils, and the application of aromatic textiles based on β-CD nano/microcapsules. Systematic research on the preparation of aromatic textiles facilitates the realization of green and simple industrialized large-scale production, providing needed application potential in the fields of various functional materials.

Glutathione-Responsive Pyraclostrobin-Loaded Polyurea Microcapsules for Their Intelligent Controlled Release

The utilization of intelligent controlled release technology to create stimuli-responsive pesticide formulations has been shown to effectively improve pesticide efficacy and reduce environmental pollution. Herein, a glutathione-responsive release polyurea (PU) microcapsules (MCs) loaded with pyraclostrobin were developed via the interface polymerization method. The pyraclostrobin-loaded PU-MCs showed a regular spherical shape with an average diameter of 480 nm. It also showed good thermal stability and rheological properties. Furthermore, the pyraclostrobin-loaded PU-MCs exhibited favorable wettability on wheat leaves, which was beneficial for enhancing the retention capacity of pesticide droplets and improving pesticide utilization. The pyraclostrobin can be released from MCs and directly proportional to glutathione (GSH) concentrations with Fickian diffusion. Importantly, the control efficacy of pyraclostrobin-loaded PU-MCs against Fusarium graminearum was positively correlated with GSH, indicating a promising candidate for a controlled release of pesticides in agriculture and laying the foundation for further field experiments.

Modeling the release of food bioactive ingredients from carriers/nanocarriers by the empirical, semiempirical, and mechanistic models

The encapsulation process has been utilized in the field of food technology to enhance the technofunctional properties of food products and the delivery of nutraceutical ingredients via food into the human body. The latter application is very similar to drug delivery systems. The inherent sophisticated nature of release mechanisms requires the utilization of mathematical equations and statistics to predict the release behavior during the time. The science of mathematical modeling of controlled release has gained a tremendous advancement in drug delivery in recent years. Many of these modeling methods could be transferred to food. In order to develop and design enhanced food controlled/targeted bioactive release systems, understanding of the underlying physiological and chemical processes, mechanisms, and principles of release and applying the knowledge gained in the pharmaceutical field to food products is a big challenge. Ideally, by using an appropriate mathematical model, the formulation parameters could be predicted to achieve a specific release behavior. So, designing new products could be optimized. Many papers are dealing with encapsulation approaches and evaluation of the impact of process and the utilized system on release characteristics of encapsulated food bioactives, but still, there is no deep insight into the mathematical release modeling of encapsulated food materials. In this study, information gained from the pharmaceutical field is collected and discussed to investigate the probable application in the food industry.