An optimized chitosan/alginate-based microencapsulation of lime peel essential oil and its application as an antibacterial textile.

A functional textile immobilized by microcapsules of the lime peel essential oils of C. aurantifolia (LPEO) was prepared and characterized. A varied amount of Chitosan/Alginate (CH/AG) ratios, followed by a mass of LPEO and concentration of sodium tripolyphosphate (STPP) crosslinker, was optimized sequentially to coacervate LPEO using a Tween 80 emulsifier. An antibacterial assay against both Gram-positive and Gram-negative bacteria was further evaluated for the embedded microcapsules. The LPEO (0.2 g) was effectively coacervated by CH/AG (5:3) crosslinked by 2% of STTP to give a yield, oil content (OC), and encapsulation efficiency (EE) of 53.45 ± 2.16%, 65.08 ± 2.60% and 85.04 ± 0.70% respectively. A rough spherical shape of LPEO microcapsules was homogeneously observed with an average particle size of 0.757 mm. An Avrami's kinetic model revealed the release mechanism of the core following zero-order kinetics (k = 1.11 ± 0.13 × 10-9 s-1, Ea = 70.21 kJ/mol). The LPEO microcapsules demonstrated good thermal stability up to 122 °C and maintained 38% OC at ambient temperature for four weeks. A 70.34 ± 4.16% of the LPEO microcapsules were successfully overlaid onto the gauze with citric acid binder and sodium phosphate catalyst. Overall, the immobilized microcapsules exhibited strong inhibition against S. aureus and moderate against S. epidermidis, E. coli, and K. pneumonia.

Microencapsulation of Citrus aurantifolia essential oil with the optimized CaCl2 crosslinker and its antibacterial study for cosmetic textiles.

A functional fabric immobilized by the microcapsules of C. aurantifolia lime essential oil (LO) was prepared and characterized. A varied amount of CaCl2 crosslinker was optimized to coacervate LO using alginate-gelatin biopolymers and Tween 80 emulsifier. A further evaluation of the immobilized LO microcapsules for the antibacterial effect against both Gram-positive and Gram-negative bacteria was conducted. The optimized alginate/gelatin-based microcapsules were effectively crosslinked by 15% CaCl2 with an yield, oil content (OC), and encapsulation efficiency (EE) of 39.91 ± 3.10%, 78.33 ± 7.53%, and 90.27 ± 5.84%, respectively. A spherical shape of LO microcapsules was homogeneously found with an average particle size of 1.394 µm. A first-order kinetics mechanism for the release of LO out of the microcapsules was modeled by Avrami's kinetic equation (k = 1.60 ± 3.68 × 10-5 s-1). The LO microcapsules demonstrated good thermal stability up to 100 °C and maintained 51.07% OC and 43.56% EE at ambient temperature for three weeks. Using a pad dry method and citric acid binder, LO microcapsules were successfully immobilized on a cloth with a % add on 30.60 ± 1.80%. The LO microcapsules and the immobilized one exhibited a moderate ZoI of bacterial growth for Gram-positive S. aureus and S. epidermidis as well as Gram-negative E. coli and K. pneumonia. Further washing test toward the functional fabric showed that the LO microcapsules incorporated into the fabric were resistant to five cycles of normal washing with a mass reduction of 22.01 ± 1.69%.

The Development of the Antibacterial Microcapsules of Citrus Essential Oil for the Cosmetotextile Application: A Review.

Essential oils (EOs) obtained from the Citrus genus were reported to exhibit good antimicrobial activity. Therefore, they can potentially be applied in daily necessities such as textile sectors as antibacterial functional fabric products. However, a packaging technique to retain such volatile and labile active substances is compulsory. In particular, microencapsulation was found to be a common coating technique employed to protect EOs from the effects of light, heat, humidity, stability, and controlled release of active substances. Various microencapsulation techniques have been introduced, but the most widely used method is complex coacervation, as it is simple, inexpensive, and capable of snaring high essential oils. Hence, this review focused on the microencapsulation of the most consumable citrus EOs with complex coacervation methods and their immobilization on commonly carried-out fabrics. In addition, it also discusses the isolation methods of the EOs, their chemical composition, and the mechanism of antibacterial action.

Microencapsulation of lime (Citrus aurantifolia) oil for antibacterial finishing of cotton fabric.

Functional cotton fabric incorporated with antibacterial microcapsules of lime (C. aurantifolia) essential oil (LO) was prepared. The coacervation method, employing two biopolymers of alginate and gelatin as the shells, was preferentially selected to produce the LO microcapsules, whereas immobilization of the LO microcapsules onto the fabric was done using the pad-dry-cure method using various concentrations of citric acid binder. The antibacterial inhibition zone of the functional fabric was subsequently analysed using the Kirby Bauer method. The LO microcapsules were produced with a yield, encapsulation efficiency (EE), and oil content (OC) of 47 ± 4%, 84 ± 11%, and 58 ± 4%, respectively. The homogenous spherical and soft microcapsules (1.554 µm) bonded effectively by 4% citric acid onto the surface of the fabric and detached back by only 3% after 15 cycles of washing. Overall, the optimized functional fabric exhibited the highest antibacterial activities among others against typical skin bacteria, such as S. aureus, E. coli, K. pneumoniae, and S. epidermidis, and thus it can be potentially applied to obtain antibacterial functional textile.