Exploring the Connection between the Occurrence and Intensity of "Grubby" Defect and Volatile Composition of Olive Oil

This study investigated the relationship between the "grubby" sensory defect in virgin olive oil (VOO), caused by olive fruit fly (Bactrocera oleae) infestation, and its volatile composition. Leccino cultivar olives with 0%, 50%, and 100% infestation were processed. 100% infestation reduced oil quality, but fatty acid composition remained unaffected. Sensory quality and positive attributes decreased with increased infestation, while "grubby" defect intensity increased proportionally. This defect correlated strongly with concentrations of 3-methylbutanal, 2-methylbutanal, β-ocimene, ethyl 2-methylbutyrate, dimethyl sulfoxide, 4-methyl-5H-furan-2-one, α-farnesene, 6-methyl-5-hepten-2-one, 1-octanol, E-2-nonen-1-ol, benzeneacetaldehyde, heptanal, and octanal, suggesting their combined contribution to the "grubby" flavor. These findings could aid in developing strategies to support sensory analysis for olive oil quality classification and defect confirmation.

Karolina Brkić Bubola, Igor Lukić, Marin Krapac, Olivera Koprivnjak