Rapid quantification of clove (Syzygium aromaticum) and spearmint (Mentha spicata) essential oils encapsulated in a complex organic matrix using an ATR-FTIR spectroscopic method.

Christopher Michael Fellows,José Daniel Wicochea Rodríguez,Stéphane Peyron,Peggy Rigou,Pascale Chalier

doi:10.1371/journal.pone.0207401

Abstract

Essential oils (EOs) are often encapsulated in various and complex matrices to protect them against potential degradation or to control their release. To achieve an optimum use in food products, their rapid and precise quantification after encapsulation and storage is required. Hence, a rapid ATR-FTIR method was developed and tested with two encapsulated essential oils (EOs): clove (Syzygium aromaticum) and spearmint (Mentha spicata);. Despite, the complexity of the matrix, this method coupled with univariate or multivariate regression models exhibited high potential for global quantification of the two encapsulated EOs. For clove EO, in relation to the major presence of eugenol and eugenol acetate, an analysis based on a unique band (1514 cm-1) was sufficient to obtain a good prediction with RMSEP value of 0.0173 g of EO per g of matrix. For spearmint oil which is characterized by numerous terpenoid compound, three bands (799, 885, and 1680–1676 cm-1) were suitable for a good prediction with RMSEP value of 0.0133. ATR-FTIR method was compared with a reference gas chromatography FID quantitative method in an EO release experiment and its efficiency was evaluated through modeling by the Avrami equation. Beside time saving, the ATR-FTIR method was also capable of monitoring the EO profile. This method could be easily adapted as a routine analysis in the EOs industry as quality control.

Highlights

Essential oils (EOs) are a complex phytochemical mixtures of aroma compounds with a high value in a wide spectrum of industrial applications such as food and pharmaceutical ingredients and fragrance or pesticide[1,2,3,4,5,6]
Madagascar is the origin of the clove EO used in this study, but it showed a similar chemical composition as a Turkish clove bud EO where eugenol (87%) and eugenol acetate (8%) represented 95% of the whole EO at the detriment of β-caryophyllene (3.56%).[29]
The clove EO differed in composition and proportion of those identified by Hossain et al, (2014) and obtained from varieties of clove collected in different countries of the gulf regions

Summary

Introduction

Essential oils (EOs) are a complex phytochemical mixtures of aroma compounds with a high value in a wide spectrum of industrial applications such as food and pharmaceutical ingredients and fragrance or pesticide[1,2,3,4,5,6]. Regardless of the application, EOs are often used after encapsulation in synthetic or bio based materials to protect them against losses during processing and storage, to protect their components against heat-induced degradation, to stabilize them against unwanted changes, and to control their release or facilitate their. ATR-FTIR method to quantify encapsulated essential oils collection and analysis, decision to publish, or preparation of the manuscript

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Conclusion