Microencapsulation of Citrus aurantifolia essential oil with the optimized CaCl 2 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 CaCl 2 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% CaCl 2 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%.