PACKAGING OF EXTRA VIRGIN OLIVE OIL: GENERAL CONSIDERATIONS

We can assert that a container must possess a series of properties and characteristics to be considered good:

• Those related to the material properties with which the container is made, its shape and size, and the accompanying accessories (cap, label/lithography).
• The consumer must understand that the importance of the packaging in Extra Virgin Olive Oils (EVOO) and all oils should not prioritize the level of elegance that a unique and exclusive design may provide to the container, but rather the preservation of the organoleptic qualities of the contained EVOO.

As emphasized by Alicia Serano in IFAPA 2017: "Several scientific reports demonstrate that the format (size) and material of the container directly influence the preservation of EVOO. This fact applies to all edible oils."

Therefore, the consumer must not forget that the container is responsible for, first and foremost, protecting and preserving the EVOO, and secondly, identifying the brand and attracting the buyer's attention. However, more frequently than desired, this order is inverted. We must also note that the container equally affects product safety during transportation and marketing, considering online commerce. Thus, the choice of container type should be related to the container's rotation time, considering this time from the moment it is filled until the user consumes the content, knowing that the degradation rate of oil is higher after the container is opened for consumption. Below are some considerations to take into account when choosing our product:

• When buying a new product from a supermarket shelf, the first thing we notice is the design of its packaging, followed by the label or lithography. The packaging design is referred to as the 'silent salesman' in marketing, and on some occasions, it can also be misleading. A product with an eye-catching design (packaging + label or lithography) can attract customers and give them a perception of higher quality. Therefore, remember that an attractive design serves no purpose if, due to the container, the Extra Virgin Olive Oil becomes rancid (oxidized) shortly after. Don't be deceived by the design of the packaging: the quality of the contained EVOO is what matters.
• Once the appeal of the design is surpassed, as a consumer, you must know that the most crucial aspect of an EVOO container is the material from which it is made: the quality of the cap and then the design. The material of the container and the cap are related to the evolution of the quality of EVOO, both in its commercial life and consumption. Later on, we will analyze in detail the different types of packaging used for Extra Virgin Olive Oil.
• Oxidative rancidity, also known as autooxidation from a quality perspective, is the most important factor to consider and understand in order to avoid it. In this case, it refers to the reaction of atmospheric oxygen with the double bonds of unsaturated fatty acids, favored by oxygen, temperature, light, and metallic ions like iron and copper. The autooxidation reaction (rancidity) cannot be entirely prevented unless the oil is frozen, but it is possible to slow it down. This is the main objective of this report.

We know that we cannot completely stop the process of oil oxidation (rancidity), but it is essential to understand how to slow it down. Extra Virgin Olive Oil (EVOO) preserves much better than other types of edible oils, thanks to the presence of phenolic compounds that act as natural antioxidants. We can affirm, without hesitation, that in oils, the time of packaging works against quality. The speed at which the quality degrades in EVOO depends on:

• Its concentration of polyphenols, which are powerful natural antioxidants that protect EVOO from the passage of time. The higher the polyphenol content, the longer and better the original properties of the EVOO will be preserved.
• The packaging and storage conditions.

We recommend consuming fresh oils with recent packaging dates. Avoid purchasing oil from the supermarket shelf that has little turnover (no more than three months).

What are the enemies of EVOO?

We know, through numerous scientific studies, that the enemies of packaged EVOO and any oil are:

• Air: We know that air is composed of 79% nitrogen and 21% oxygen. This 21% oxygen is the necessary component for the oxidation reaction in all oils (rancidity). Therefore, we recommend: Close the container tightly after use and avoid leaving it partially empty for months. When the container is open, the oxidation capacity multiplies, so it is best to use containers that are not too large for daily use and keep them closed. Additionally, it is advisable to have a larger main container stored in a dark and cool place and a smaller container or oil dispenser for daily use, which should also be kept closed and replenished from the main container.
• Light: Light promotes photooxidation (rancidity) of the oil. Containers that allow less light to penetrate are better. Opaque containers will only receive heat energy, while transparent and translucent ones will receive both light and heat energy, with light energy being more detrimental to the packaged oils compared to ambient temperature. Therefore, we recommend: Buy Extra Virgin Olive Oil in opaque containers that protect it from light.
• Metals: Iron or copper increase the oxidation of the oil. The best container is the one that dissolves fewer metal ions, such as iron and copper, into the oil. Tinplate cans, commonly used in packaging EVOO, avoid the effect of iron as they consist of flat laminated steel with low carbon content (0.03-0.13%), coated on both sides with tin and varnish.
• High or low temperatures: The best way to preserve oil is to keep it at a low temperature. Therefore, we recommend: Store the oil at a normal temperature of 15-20°C, avoiding large temperature fluctuations. If it is colder than the recommended temperature range, nothing happens except that the oil becomes more viscous, and if it drops below 9°C, it may start to crystallize (freeze) due to its high oleic acid content. In this case, particles and white specks may appear in suspension. It is normal to see bottles of EVOO with precipitates at the bottom and somewhat turbid, especially in some supermarket shelves on cold days or in cold regions. Simply place the bottle in an area at 15-20°C to return it to its normal state. During this defrosting process, some phenolic compounds and moisture will precipitate, resulting in a reduction in antioxidant activity and bitterness, a positive attribute of good EVOO. Oil can be stored in the refrigerator and can be frozen without any issues, except for the precipitation of a percentage of phenolic compounds and a slight loss of organoleptic attributes. The oxidation (rancidity) is completely under control as long as it is frozen.
• Beware of smoke and odors. We recommend: Keep your oil away from smoke and vapors produced during cooking, and always keep the container closed. EVOO acts like a sponge for absorbing odors.

Considerations to Keep in Mind

1. All actions carried out in both agricultural activities and the production and storage of oil to achieve a high-quality Extra Virgin Olive Oil (EVOO) can be compromised if the packaging process is not done correctly. Therefore, this stage is critical for the quality of the oil, and improper packaging can quickly spoil a good EVOO.
2. In practical terms, the oxidation (rancidity) of packaged oil is detected once the process has advanced, leading to the discoloration of the oil inside the container (chlorophyll is destroyed). This results in a decrease in the percentage of polyphenols and tocopherols, which are natural antioxidants beneficial to health. Harmful free radicals are also produced, affecting the distinctive taste and aroma of a good EVOO.
3. The best packaging to preserve the qualities of Extra Virgin Olive Oil, as well as other oils, is the family of bag-in-box containers, as they prevent air from entering and light from penetrating. Other suitable containers include tin cans, tetra bricks, and opaque glass.
4. Regarding the size of the container, oil is better preserved in larger formats, provided that the containers are entirely filled. However, the size should correspond to the type of consumer. In regions with high consumption, the usual format is five liters. Nevertheless, this size is too large for exports or high-end oils, where glass, tin cans, or bag-in-box containers of 500 ml, 750 ml, and 1000 ml are more common.
5. For exports or online purchases, tin cans are a good option due to their resistance during transportation, as well as bag-in-tube containers.
6. Nitrogen dosing improves the preservation of oil. It is done through the "Sparging" system, where nitrogen is bubbled directly into the EVOO to remove dissolved oxygen. This ensures that the remaining air in the container remains enriched with nitrogen, minimizing auto-oxidation.
7. When filling the container, it is essential to minimize the empty spaces (headspace) at the top of the container, as the oxygen in the air promotes oxidation. This issue does not occur with bag-in-box containers. When the container is opened, the oxidation capacity multiplies, so it is recommended to use containers of regular size that are always closed.
8. The cap must be airtight and easy to open and close during use. The closure of the bottle is crucial, and caps are often overlooked during the packaging phase, resulting in stains on the bottles, especially when they are intended for export and undergo numerous movements and temperature changes. Any pore that does not allow proper closure will facilitate oxidation, leading to the deterioration of the oil more quickly.
9. EVOO is produced over a period of approximately two to three months during the harvest, but it is consumed throughout the year. Therefore, it must be properly packaged. Purchases should be made in sequence according to consumer demand since EVOO and all oils are better preserved in bulk tanks. The packaging process plays a significant role, and it is essential for consumers to know the packaging date.
10. To counteract these oxidation processes, Extra Virgin Olive Oil contains a series of compounds with antioxidant functions. These compounds, such as tocopherols, polyphenols, and pigments, slow down the oxidation rate and offer nutritional and health benefits. Among these pigments, carotenoids inhibit the action of oxygen, while chlorophylls, in the presence of light, promote photooxidation. In darkness, they may act as antioxidants. The stability of Extra Virgin Olive Oils depends on the content of polyphenols and tocopherols found in the variety of olives used. Both natural components, present in EVOO, have antioxidant properties. For instance, EVOO obtained from the Picual olive variety, due to its high polyphenol content, exhibits greater stability and resistance to oxidation, whereas others, like those made from the Arbequina variety, may become rancid more quickly. It is crucial for consumers to be aware of this fact.