Xenovolatilomic profiling of Hass avocado (Persea americana Mill.) tissues exposed to endosulfan: identification of potential toxicity biomarkers†

Abstract

Introduction: Omics sciences, particularly metabolomics and its subfield volatilomics, investigate small molecules to understand biochemical dynamics. Volatilomics targets volatile organic compounds (VOCs), which act as biomarkers for physiological changes, environmental stress, and xenobiotic exposure. Advances in GC-MS and HS-SPME have enabled precise VOC profiling. A critical issue in food safety is pesticide contamination, notably organochlorines like endosulfan, which bioaccumulate and disrupt plant metabolomes. Hass avocado (Persea americana Mill.), rich in lipids and terpenoids, offers an ideal matrix for studying xenovolatilomic responses. Objective: This study evaluated volatilomic alterations induced by endosulfan in Hass avocado using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). It aimed to identify potential toxicity biomarkers associated with pesticide exposure, contributing to rapid, reliable detection methodologies for agricultural products. Methodology: Avocado peel, pulp, and seed were experimentally exposed to endosulfan for 8 and 20 days under controlled conditions. VOCs were extracted by HS-SPME and analyzed by GC-MS. Data were processed and subjected to multivariate statistical analyses, including Principal Component Analysis (PCA), Partial Least Squares-Discriminant Analysis (PLS-DA), random forest, variable importance in projection (VIP) scores, and receiver operating characteristic (ROC) curve analysis to identify VOCs differentially expressed under pesticide exposure. Results: Random forest and PLS-DA analyses identified five key VOCs as potential toxicity biomarkers: (E)-2-octenal (V93), oct-3-en-2-one (V86), decanal (V129), hexanal (V29), and nonanal (V102). These compounds exhibited significant concentration changes based on exposure time (8 and 20 days) and tissue type. Additionally, an unknown compound (VX83) emerged as a potential biomarker requiring future characterization. Conclusions: This study constitutes the first xenovolatilomic investigation in Hass avocado and validates the use of (E)-2-octenal, oct-3-en-2-one, decanal, hexanal, and nonanal as potential toxicity biomarkers for the early detection of pesticide-induced biochemical alterations. The integration of volatilomic profiling with multivariate statistical and biochemical analyses provides a solid foundation for developing rapid diagnostic tools and advancing computational metabolomics models for predicting pesticide-induced enzymatic inhibition processes. These findings have implications for food safety, export quality assurance, and the economic sustainability of agricultural production systems in regions like Caldas, Colombia.