Exploring Bioactive Properties of Citrus Essential Oils
Citrus processing in Morocco results in significant amounts of peel waste, which can be transformed into a valuable resource for bioactive essential oils (EOs). This study focuses on the volatile profiles of EOs derived from five distinct citrus species—namely _C. aurantium_, _C. limon_, _C. paradisi_, _C. reticulata_, and _C. sinensis_. Employing a comprehensive chemometric approach, the research aimed to delineate the volatile composition and assess both the antioxidant and antimicrobial capabilities of these EOs. Utilizing gas chromatography-mass spectrometry (GC-MS) for analysis, the study identified limonene as the predominant component, comprising 58.2% to 88.4% of the total volatile compounds. Furthermore, through unsupervised chemometric techniques such as Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), the researchers successfully categorized the citrus species into specific metabolic clusters based on their minor volatile components. The biological evaluations revealed that the EO from _C. reticulata_ exhibited the highest antioxidant capacity, with an IC50 value of 0.81 ± 0.02 mg/mL. In contrast, _C. limon_ EO showcased broad-spectrum antimicrobial activity against various microorganisms, with minimum inhibitory concentrations (MIC) ranging from 0.78 to 1.56 mg/mL.
Significance of Bioactive Markers
The findings from the supervised Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) indicated that the observed bioactivity was primarily linked to specific oxygenated monoterpenoids, particularly linalool and geranial, along with hydrocarbon monoterpenes such as α-pinene, p-cymene, and trans-α-ocimene. These compounds emerged as crucial biomarkers associated with bioactivity, boasting Variable Importance in Projection (VIP) values greater than 1, thus underscoring their significance compared to the overall abundance of hydrocarbons. This research presents a robust framework for fingerprinting citrus EOs, paving the way for their application as natural antioxidants and antimicrobial agents in food preservation and other relevant industries.
As reported by nature.com.
