Microencapsulation of Vanilla Oleoresin (V. planifolia Andrews) by Complex Coacervation and Spray Drying: Physicochemical and Microstructural Characterization

Design of gum Arabic/gelatin composite microcapsules and their cosmetic applications in encapsulating tea tree essential oil

Microencapsulation has been widely used to protect essential oils, facilitating their application in cosmetics. In this study, gelatin, gum arabic and n-butyl cyanoacrylate were used as wall materials, and composite microcapsules of tea tree essential oil (TTO) were prepared using a combination of composite coagulation and in situ polymerization methods. When the ratio of gelatin to gum arabic is 1 : 1, the ratio of TTO to n-butyl cyanoacrylate is 4 : 1, the curing time is 10 h, and the encapsulation efficiency (EE) under these conditions is 73.61%. Morphological observation showed that the composite capsule was a micron-sized spherical particle with an average particle size of 10.51 μm, and Fourier transform infrared spectroscopy (FT-IR) confirmed a complex coagulation reaction between gelatin and gum arabic, and the disappearance of the n-butyl cyanoacrylate peak indicated that the film was formed in a condensation layer. The thermogravimetric analysis (TGA) results showed that the composite capsule greatly improved the thermal stability of TTO. Rheological testing showed that the viscosity and viscoelasticity of the surface composite capsules have been improved. In addition, the composite capsule showed good stability in the osmotic environment and has good sustained-release performance and antioxidant capacity in the average human skin environment.

Advances and trends in encapsulation of essential oils

There is a huge concern regarding the potential carcinogenic and mutagenic risks associated with the usage of synthetic chemicals as preservatives in various consumer products such as food and pharmaceutical formulations. In this aspect, there is a need for the development of alternative natural preservatives to replace these synthetic chemicals. More recently, naturally occurring essential oils have emerged as popular ingredients owing to their unique characteristics like antioxidant and antimicrobial activity, to enrich and enhance the functional properties of consumer products. However, due to their high volatility and hydrophobicity, their functionality is lost and their incorporation in aqueous products is challenging. One of the promising strategies to overcome this challenge is encapsulation which involves the entrapment of the essential oil inside a biocompatible material for its controlled release and increased bioavailability. Also, the choice of encapsulation method depends on the component to be encapsulated and the shell material. In this review, encapsulation in various colloidal systems that facilitate the potential delivery of essential oils is discussed. The focus is on encapsulation techniques along with their advantages and disadvantages, encapsulation efficiency, and in vitro release studies.

Recent advances in essential oil complex coacervation by efficient physical field technology: A review of enhancing efficient and quality attributes

Although complex coacervation could improve the water solubility, thermal stability, bioavailability, antioxidant activity and antibacterial activity of essential oils (EOs). However, some wall materials (such as proteins and polysaccharides) with water solubility and hydrophobic nature limited their application in complex coacervation. In order to improve the properties of EO complex coacervates, some efficient physical field technology was proposed. This paper summarizes the application and functional properties of EOs in complex coacervates, formation and controlled-release mechanism, as well as functions of EO complex coacervates. In particular, efficient physical field technology as innovative technology, such as high pressure, ultrasound, cold plasma, pulsed electric fields, electrohydrodynamic atomization and microwave technology improved efficient and quality attributes of EO complex coacervates are reviewed. The physical fields could modify the gelling, structural, textural, emulsifying, rheological properties, solubility of wall material (proteins and polysaccharides), which improve the properties of EO complex coacervates. Overall, EOs complex coacervates possess great potential to be used in the food industry, including high bioavailability, excellent antioxidant capacity and gut microbiota in vivo, masking the sensation of off-taste or flavor, favorable antimicrobial capacity.

Current trends in flavor encapsulation: A comprehensive review of emerging encapsulation techniques, flavour release, and mathematical modelling

Food flavors are volatile compounds that impact the human sensory perception profoundly and find extensive applications in various food products. Because of their volatility and high sensitivity to pH, temperature, oxidation, and external conditions, they require adequate protection to last for a longer duration. Encapsulation plays a critical role in preserving food flavors by enhancing their thermal and oxidative stability, overcoming volatility limitations, and regulating their rapid release with improved bioavailability in food products. The current review focuses on the recent developments in food flavor encapsulation techniques, such as electrospinning/spraying, cyclodextrin inclusion complexes, coacervation, and yeast cell micro-carriers. The review also comprehensively discusses the role of encapsulants in achieving controlled flavor release, the mechanisms involved, and the mathematical modelling for flavor release. Specific well-established nanoencapsulation techniques render better encapsulation efficiency and controlled release of flavor compounds. The review examined specific emerging methods for flavor encapsulation, such as yeast cell encapsulation, which require further exploration and development. This article provides readers with up-to-date information on different encapsulation processes and coating methods used for flavor encapsulation.

Self-coacervation of carboxymethyl chitosan as a pH-responsive encapsulation and delivery strategy

Carboxymethyl chitosan (CMCS)-based complex coacervate has attracted much attention in drug oral delivery due to its pH-responsive property. As a unique ampholyte polymer, the self-coacervation of CMCS has great research potential. In this work, CMCS self-coacervates were prepared by adjusting the pH of the CMCS aqueous solution close to its isoelectric point. The Fourier-transformed infrared spectroscopy (FTIR) results revealed that electrostatic interactions, hydrogen bonding, and hydrophobic interactions were involved in the self-coacervation of CMCS. The obtained self-coacervates presented a dense surface structure, and were stable at a wide pH range of 3.0-6.0, and gradually dissolved under basic conditions. Although self-coacervation decreased the crystallinity and thermal stability of CMCS, the obtained coacervates showed excellent pH-responsive properties and ionic strength stability. We also investigated its potential in lactoferrin (LF) encapsulation and oral delivery. The CMCS self-coacervates exhibited a high encapsulation efficiency (EE) of 94.79 ± 0.49% and loading capacity (LC) of 26.29 ± 0.52% when the addition amount of LF was 2 mg. The simulated gastric digestion results demonstrated that CMCS self-coacervates could protect more than 80% of LF from hydrolysis and maintain the bioactivities of LF. Accordingly, the self-coacervation of CMCS could be used as a pH-responsive encapsulation and delivery strategy.

Encapsulation of Flavours and Fragrances into Polymeric Capsules and Cyclodextrins Inclusion Complexes: An Update

Flavours and fragrances are volatile compounds of large interest for different applications. Due to their high tendency of evaporation and, in most cases, poor chemical stability, these compounds need to be encapsulated for handling and industrial processing. Encapsulation, indeed, resulted in being effective at overcoming the main concerns related to volatile compound manipulation, and several industrial products contain flavours and fragrances in an encapsulated form for the final usage of customers. Although several organic or inorganic materials have been investigated for the production of coated micro- or nanosystems intended for the encapsulation of fragrances and flavours, polymeric coating, leading to the formation of micro- or nanocapsules with a core-shell architecture, as well as a molecular inclusion complexation with cyclodextrins, are still the most used. The present review aims to summarise the recent literature about the encapsulation of fragrances and flavours into polymeric micro- or nanocapsules or inclusion complexes with cyclodextrins, with a focus on methods for micro/nanoencapsulation and applications in the different technological fields, including the textile, cosmetic, food and paper industries.