Effect of supercritical CO2 fractionation of Tahiti lemon (Citrus latifolia Tanaka) essential oil on its antifungal activity against predominant molds from pan bread

Author(s)

Gasparetto, Bruna dos Reis ; Moreira, Rafael Chelala ; de Melo, Rayanne Priscilla Franca ; Lopes, Aline de Souza ; Rocha, Liliana de Oliveira ; Pastore, Glaucia Maria ; Bicas, Juliano Lemos ; Martinez, Julian ; Steel, Caroline Joy

• Document type: Journal article
• Source: Food Research International; v. 162, p. 11-pg., 2022-12-01.

Abstract

This study aimed to verify the in vitro antifungal activity of Tahiti lemon essential oil (LEO) and its fractions, obtained by supercritical CO2 fractionation, against Penicillium sumatrense and Aspergillus niger isolated from pan bread. For this, LEO was solubilized (20 MPa and 40 degrees C) and fractionated (10 MPa and 40 degrees C) in supercritical CO2, resulting in soluble (SF) and precipitated (PF) fractions. LEO, SF and PF volatile compounds were identified by gas chromatography coupled to mass spectrometry (GC-MS) and semiquantified by gas chromatography with a flame ionization detector (GC-FID). To evaluate the in vitro antifungal activity of the essential oils (LEO, SF and PF), the minimal inhibitory and fungicidal concentrations (MIC and MFC, respectively) were determined using the 96-well plate methodology. For this, pan breads ware prepared with no preservatives and stored for seven days at 25 degrees C, and their pH, water activity and moisture contents were determined. Then, two predominant species (Penicillium sumatrense and Aspergillus niger) were isolated from pan breads, characterized according to their morphological and molecular characteristics, and were used in the antifungal activity studies. LEO and its fractions presented monoterpenes, sesquiterpenes and their oxygenated derivatives in their composition. Specifically, limonene was the major component identified in the essential oils. SF showed greater antifungal potential than PF and LEO, showing that supercritical CO2 fractionation could improve the antifungal efficiency of LEO. The results suggest that LEO and its fractions may contribute to the inhibition of Aspergillus niger and Penicillium sumatrense growth in pan breads. (AU)

• FAPESP's process: 20/06814-3 - ENZYTERP: enzymatic biotransformation of terpenes for the production of bioaromas
• Grantee: Juliano Lemos Bicas
• Support Opportunities: Regular Research Grants