Sustainable Packaging for Extra Virgin Olive Oil: A Comparative Shelf-Life Study

The ability of ultraviolet-absorbing glass (UVAG) and 100% recycled green polyethylene terephthalate (rPET) bottles to preserve the quality of six blended Italian extra-virgin olive oils (EVOOs) was investigated over 12 months of simulated commercial storage (25 °C, 12 h/day light exposure). Samples from both UVAG and rPET bottles were collected at 30-day intervals and analysed for regulatory quality indices (free acidity, peroxide value, K₂₃₂, K₂₇₀ and ΔK), antioxidants, volatile compounds and sensory characteristics. The resulting chemical and sensory dataset was further explored using multivariate statistical analysis. At the start of storage, all EVOOs met the regulatory standards for the "extra-virgin" category. Free acidity remained substantially unchanged throughout 12 months, whereas K₂₃₂ values consistently remained below the legal limit. In contrast, K270 and ΔK, markers of secondary oxidation, increased progressively, although regulatory thresholds were exceeded earlier in EVOOs stored in rPET than in UVAG bottles. Storage also induced a gradual depletion of total hydrophilic phenols and α-tocopherol, together with significant changes in the volatile profile, including a decrease in lipoxygenase-derived C₅–C₆ aldehydes and alcohols, responsible for fruity and green sensory notes, and an increase in oxidation-related C₇–C₁₀ aldehydes, associated with rancid off-flavour. Multivariate statistical analysis showed that EVOO compositional differences were the primary source of variability, followed by storage time, while the effect of packaging became more evident as storage time increased. Overall, these findings highlight the potential of 100% recycled green rPET for EVOO packaging as a sustainable solution combining preservation performance comparable to UVAG glass with improved environmental and economic sustainability.