Malgrado bag in box, ceramic and painted glass bottles are increasingly finding space in the containers of extra virgin olive oil – with packaging solutions that are also really interesting from a marketing perspective – there is no doubt that the traditional glass bottle have always represented the identity symbol of that productIn this context, over time, it also seemed natural to move from transparent glass to dark green glass, to match the shade of the bottle to that of its contents. But Is green really the best bottle color for storing extra virgin olive oil? It would certainly not seem so, listening to the Prof. Maurizio Servili, Professor of Food Science and Technology at the University of Perugia, a point of reference for research in the oil sector.
In fact, a workshop entitled 'The colour of quality' was held in the Umbrian university over the past few days, in which the study conducted by Prof. Servili on the other hand was presented. Ets Foundation Carapelli Nutritional Institute (Inc)The study aimed to evaluate innovative systems for determining the shelf life of chemical and sensory parameters of extra virgin olive oil, taking into account that the preservation of the quality of packaged extra virgin olive oil is influenced by both the type of packaging and shelf storage conditions.
In his speech, Prof. Maurizio Servili highlighted how “the study evaluated, for the first time, the impact of different glass color shades such as light green, amber, Uvag green (Ultraviolet absorbing glass, ed.) and the blue, on the oxidative stability of extra virgin olive oils exposed to light, simulating the storage conditions typical of points of sale.
To evaluate shelf life - he added - New instrumental parameters have been introduced to better interpret the oxidation level of oils and their degree of freshness. The results obtained, testing oils of different geographical origins and chemical compositions, have highlighted that Blue glass has a protective effect on extra virgin olive oil superior to all other glass colors testedThe most significant effects were observed on the evolution of traditional instrumental parameters such as K270 and innovative ones such as the evolution of oxidized phenolic compounds, newly formed oxidative volatile compounds and pyropheophytins”. (pyropheophytins are the Chlorophyll pigment degradation compounds from thermal degradation of olive oil)
In essence, blue glass bottles are particularly effective in:
- reduce the absorption of light radiation that is most harmful to phenolic compounds and fatty acids;
- maintain aroma, taste and colour unchanged for longer periods;
- minimize the formation of oxidative by-products.
These results, it was emphasized, open up new perspectives for the entire extra virgin olive oil supply chain in terms of perceived quality and product shelf life, because the choice of blue glass packaging represents not only an aesthetic choice, but a functional innovation based on rigorously scientific principles.
During the workshop, the Venice Glass Experimental Station illustrated the optical and technical properties that make glass an ideal material for protecting and preserving food, emphasizing how the blue color of glass selectively filters out the most harmful wavelengths, how glass is completely impermeable to atmospheric gases, providing an effective barrier against oxygen, and how glass's compatibility with recycling cycles allows for perfect environmental sustainability.
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