Effect of packaging material headspace, oxygen and light transmission, temperature and storage time on quality characteristics of extra virgin olive oil

Abstract

The effect of packaging parameters (transmission to light and oxygen, headspace volume) and storage temperature on quality characteristics of extra virgin olive oil (EVOO) was studied as a function of storage time (0–12 months). Packaging materials tested included clear glass, clear polyethylene terephthalate (PET), clear PET + UV blocker, clear PET covered with aluminum foil and clear polypropylene (PP) bottles. Quality parameters monitored over the 12 month storage period included: acidity, peroxide value (PV), spectrophotometric indices ( K 232, K 270) and color. Results showed that the best packaging material for olive oil packaging was glass followed by PET. PP proved to be unsuitable for such an application. Exposure of olive oil samples to light, high storage temperatures (35 °C) and large headspace volumes caused substantial deterioration in product quality parameters. The most pronounced effect was that of temperature and light while the smallest effect was that of headspace volume and packaging material permeability to oxygen. Olive oil color was not substantially affected by storage conditions with the exception of storage of olive oil at 35 °C exposed to light for 12 months. Shelf life of extra virgin olive oil was 6 months packaged in clear glass in the dark at temperatures up to 22 °C; 3 months in clear PET in the dark at 22 °C and less than 3 months in clear PP in the dark at 22 °C. When exposed to light, shelf life of olive oil was 9 months when packaged in PET + aluminum foil; 3 months in PET + UV blocker and less than 3 months in clear PET at 22 °C. Product shelf life was less than 3 months at 35 °C. Finally oxygen in the headspace of olive oil resulted in deterioration of product quality. The relative contribution of parameters studied to the retention of olive oil quality was: temperature ≈ light > container headspace > packaging material oxygen permeability.