Fast-dissolving carvacrol/cyclodextrin inclusion complex electrospun fibers with enhanced thermal stability, water solubility, and antioxidant activity

Carvacrol is a known antioxidant molecule and commonly used in food and cosmetics as a flavor and fragrance agent; however, carvacrol has major issues such as high volatility, low water solubility, and stability. In this study, carvacrol/cyclodextrin inclusion complex fibers (carvacrol/CD-IC fibers) were produced via electrospinning in order to enhance thermal stability, water solubility and shelf-life of carvacrol having antioxidant activity. The phase solubility and computational modeling studies showed that carvacrol can form inclusion complexes with two types of modified CDs, hydroxypropyl-beta-cyclodextrin (HP beta CD) and hydroxypropyl-gamma-cyclodextrin (HP gamma CD). The carvacrol/cyclodextrin inclusion complex electrospun fibers (carvacrol/HP beta CD-IC fibers and carvacrol/HP gamma CD-IC fibers) were obtained as free-standing fibrous webs. Although pure carvacrol is highly volatile, the electrospun carvacrol/CD-IC fibers were quite effective to preserve high amount of carvacrol due to the inclusion complexation. In addition, carvacrol/CD-IC fibers have shown higher temperature stability for carvacrol. Moreover, carvacrol/CD-IC fibers showed more effective antioxidant activity as compared to pure carvacrol. The carvacrol/CD-IC fibrous webs have shown fast-dissolving character in water due to the enhanced water solubility of carvacrol/CD-IC and their ultrafine fiber structure. In short, encapsulation of carvacrol in electrospun CD-IC fibrous webs has shown potentials for food and oral care applications due to free-standing and fast-dissolving character along with high water solubility, high temperature stability and enhanced antioxidant by carvacrol/cyclodextrin inclusion complexation.