Simultaneous quantification of the main components of Thymus vulgaris essential oil in edible coating formed from nanocapsules using HS-SPME-GC-FID

Abstract The use of edible coatings (ECs) containing essential oils (EOs), such as that derived from the Thymus vulgaris plant (EO- Tv ), offers a natural option for preserving and increasing the shelf life of fruit and vegetable products. However, considering their physicochemical properties, the incorporation of EOs into nanocapsules (NCs) represents an alternative to reduce their volatility and oxidation. In this way, quantitative determination of the EOs incorporated into NCs is necessary for simultaneous monitoring of their main components during the nanoencapsulation process, as well as for the future precise and accurate dosage of EO components in fruit and vegetable products. In this study, ECs were formed from NCs loaded with EO- Tv and sodium alginate (AL). The EO- Tv was characterized through GC-MS and GC-FID analysis, and it was found that the major component of EO- Tv was thymol, with an abundance of 30.91%. Subsequently, an analytical method based on HS-SPME-GC-FID was developed and validated for quantification of the EO- Tv encapsulated in NCs and incorporated into the EC. The method was found to be precise and accurate for quantification of the main components of EO- Tv in the formed EC. Once the analytical method was validated, it was established that the encapsulation efficiency was greater than 50% in the case of NC-EO- Tv purified via evaporation at reduced pressure. On the other hand, 35.78 μg cm −2 of thymol was quantified in the EC formed from the NCs and AL. The present work presents an analytical tool for simultaneous quantification of the main components of EO- Tv in NCs, as well as in the ECs formed with NCs, promoting its potential application in fruit and vegetable products.