Evaluating the Effect of Packaging Materials on Extra Virgin Olive Oil Quality Under Simulated Household Use and...

Extra virgin olive oil (EVOO) is prone to oxidative degradation during storage, especially after opening, when exposure to oxygen and light accelerates the depletion of antioxidants and promotes the formation of oxidation products, including hydroperoxides and C₇-C₉ aldehydes associated with rancidity. Packaging materials play a critical role in preserving EVOO quality in real-use conditions. This study comparatively evaluated the effectiveness of three widely used packaging materials: green polyethylene terephthalate (PET), bag-in-box (BB), and chrome-plated tin (CPT) in preserving regulatory, sensory, and health-related qualities of EVOO under simulated household use and storage conditions.

PET, BB, and CPT containers (3 L) were totally filled with the same EVOO and stored at 25 °C under a 12 h light/dark cycle, with 75 mL withdrawn daily for 40 days to mimic consumer use. Every 10 days, regulatory quality indices (free acidity (FA), peroxide value (PV), K₂₃₂, and K₂₇₀), antioxidants, volatile compounds, and sensory attributes were evaluated.

Free acidity, K₂₃₂, and K₂₇₀ increased slightly in EVOOs across all containers, while EVOO stored in PET showed a sharp rise in PV, exceeding the legal limit after 30 days. Antioxidant depletion was significantly (p ≤ 0.05) more pronounced in the EVOO stored in PET (44% α-tocopherol and 26% total phenols, respectively) than in BB (1% and 11%) and CPT (5% and 12%). The EVOO stored in PET also showed a reduction in C₅-C₆ aldehydes (-26% and -24% compared to BB and CPT, respectively), alongside an accumulation in C7-C9 aldehydes (+8% and +5%), exhibiting higher loss of C₅-C₆ aldehydes and of C₇-C₉ aldehydes, which is responsible for fruity-green notes and rancid defect, respectively, compared to BB and CPT.

Overall, the EVOOs stored in BB, followed by CPT, showed higher oxidative stability than those stored in PET, resulting in prolonged "extra virgin" classification and improved preservation of antioxidant content, volatility profile, and sensory quality during consumer-level storage.