Transcript
Page 1: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16Extra-virgin olive oil packagingSara Limbo,1 Claudio Peri2 and Luciano Piergiovanni11Department of Food, Environmental and Nutritional Sciences,University of Milan, Milan, Italy2University of Milan, Milan, Italy

Abstract

The packaging process is described as a sequence of operations from the purchaseorder to shipment of the product to the customer. The characteristics and perfor-mance of glass, metal and plastic containers in the packaging of extra-virgin oliveoil are presented and compared in terms of cost, protection from light and oxygen,possibility of recycling and reuse, mechanical resistance and inertness. Various fill-ing and closing techniques are described. Finally, the limitations and possibilities oflabelling are discussed.

16.1 Introduction

Packaging operations can be classified in three levels as:

• primary packaging, which is in direct contact with the product

• secondary packaging, containing several primary packages – for example, acorrugated case;

• tertiary packaging, containing a number of secondary packages – for example,a stretch-wrapped pallet of corrugated cases.

Only primary packaging will be dealt with in this handbook. Primary packagingmust satisfy five principal and interconnected functions: containment, protection,convenience, communication, and sustainability.

The Extra-Virgin Olive Oil Handbook, First Edition. Edited by Claudio Peri.© 2014 John Wiley & Sons, Ltd. Published 2014 by John Wiley & Sons, Ltd.

Page 2: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

180 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Containment

This is the basic function of packaging and it mainly concerns the size, weight andshape of the package. In the case of extra-virgin olive oil, this point deserves carefulconsideration. In fact, for a product that is consumed at a rate of 10–20 ml per personper day, the sizes and volumes presently used in distribution and retail outlets, as wellas in restaurants, are totally disproportionate. In many restaurants, a 750 ml bottle isused to serve customers by putting it on the restaurant’s tables for days or weeks at animproper temperature and in large contact with air. These are unsuitable conditionsfor handling good or excellent extra-virgin olive oil.

The appropriate solutions for restaurants and families are twofold: (i) use smallercontainers so that the contents are used before being spoiled, and (ii) store extra-virgin olive oil in suitable dispensers kept at the proper storage conditions, fromwhich single or multiple portions can be taken to be served at the table according tothe need. The role of packaging in this scenario is essential.

Protection

Edible oils in general, and extra-virgin olive oil in particular, need containers withspecific protection properties at every step of the chain from production throughstorage, transportation, distribution, and final selling and use:

• First of all, the oil should be protected from contaminating substances fromthe environment and especially moisture, oxygen, odours, smoke, dust, micro-organisms.

• Secondly, the oil should be protected from nonpolar, hydrophobic contaminantssuch as solvents or additives, monomers and degradation products derivingfrom contact materials.

• Thirdly, the oil should be protected from light, which accelerates photo-oxidation.

• Finally, like any other food whose excellence is based on origin and authentic-ity, containers must be fraud and tamper proof.

Convenience

Characteristics that make packages easy to carry or hold or open and reclose or thatmake it easier to pour the oil without dripping are so important and influential inconsumer choice that this function is referred to as the ‘smart function’ of packaging.Small size, single-portion containers and the dispensers discussed under point 16.1.1(containment) are also convenience requisites.

Page 3: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.2 THE PACKAGING PROCESS 181

Communication

A frequently cited sentence is: ‘A package must protect what it sells and sellwhat it protects’. Distinctive branding and labelling on containers should enablesupermarkets to function on a self-service basis. At the time of purchase, consumersare greatly influenced by easy-to-catch and easy-to-read information on the package.Nutritional information, country or region of origin, date for best consumption,harvesting year, certification marks and so forth are all crucial points of informationfor consumer decision. Communication also includes the United Product Code(UPC), which can be rapidly read by modern scanning equipment at the retailcheckout.

Sustainability

Sustainability has become a critical issue in packaging research and development,but also an essential factor in consumer choice. The possible adverse impact ofpackaging on the environment is a hot technical, regulatory and political issue. Notsurprisingly, food-packaging materials are the focus of many texts on environmentalprotection. Reducing the amount of waste due to packaging materials and recyclingof packages is key to future development.

Economic sustainability is another aspect to be considered. The cost of the pack-age should be in a reasonable relationship with the cost of the product.

16.2 The packaging process

The packaging operation, consisting in the sequence of filling-closing-labelling ispart of a more complex packaging process whose optimization criteria are muchdifferent from those of olive production and milling. It requires relatively com-plex materials and equipment, significant investments and close connections withmarketing.

At the same time, packaging is so critical for marketing success that many small-sized companies producing relatively low amounts of excellent olive oil, have theirown bottling and packaging facilities. Large and small packaging plants with oper-ating systems from full automation to manual coexist in the extra-virgin olive oilworld.

Co-packaging is a new approach to packaging in areas where the size of man-ufacturing companies is too small to afford the cost and operation of a modernpackaging plant. A contract packer, or co-packer, is a company that specializes inpackaging products as an outsourcing service for other manufacturing companies.

Page 4: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

182 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

A co-packer works under contract with a hiring company and is fully responsiblefor the packaging process. The main benefits of co-packaging are:

• sharing investments to reach a high technological level, which may be neededfor packaging containers of special size and form, inert-gas blanketing,refilling-proof closures, and so on

• bringing together know-how and experience in a unique place, developing newpractices and solutions

• raising the quality and safety level of the packaging process

• improving the efficiency of the packaging process due to large volumes andeconomies of scale.

A co-packaging centre can hire staff and workers with specific knowledge andskills in packaging; it can more easily obtain packaging material at good economicprices from selected suppliers.

Figure 16.1 shows the flowchart of the olive oil packaging process. It shows thata packaging process starts from a purchase order from a customer, defining thequality and quantity requested (as well as time and cost). The end of the processis the packaging company forwarding the extra-virgin olive oil in packages to thecustomer, complying with the legal and technical terms according to agreed uponrequirements.

The first critical operation of the process consists in defining and forming a‘packaging lot’, which is a homogeneous batch of oil conforming to customerrequirements. There are two possibilities: the requirements are met by an existingstorage batch or a new ‘packaging lot’ must be obtained by suitably blending oilsfrom various storage batches.

Blending is a complex operation requiring high-level skill. It can be carried outaccording to two very different approaches or any suitable combination of the two:

• The most sophisticated approach consists in applying a computational opti-mization procedure. A set of optimization algorithms elaborate analytical dataand the cost of oils from different storage batches. On this basis, the percentageweight of different batches that must be blended are defined in order to obtaina packaging lot conforming to the customer requirements at the lowest cost.

• The simplest approach is based on highly skilled expert tasting of differentblends until the required sensory profile is achieved. This procedure is oftenapplied to small-scale production of excellent olive oils.

After the new packaging lot is made, it undergoes a final and complete evaluationto characterize the analytical and sensory profile of the oil. If the result of this evalu-ation is not completely satisfactory, some feedback and refining of the blending maybe necessary. If results conform to the requirements, the oil is sent to the packagingoperation.

Page 5: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.2 THE PACKAGING PROCESS 183

Purchase order

Oil storage

Formation of apackaging lot

Analytical check andcharacterization

Filling

Closing

Labelling

Automatic or visualcontrol

Recovery, recyclingor disposal

Blending, filtering

Containers: selectionand cleaning

Closures withtamper-proof,pouring features

Labels Traceabilitycode

To storage – secondary and tertiary packaging - forwarding to customers

Figure 16.1 The flowchart of the packaging process.

The formation and characterization of packaging lots is the most critical step ofproduct traceability (Chapter 19). This is the step in which the identity and authen-ticity of the product are verified and guaranteed to the final consumer. An accurateand reliable record of this step represents the point of connection of the marketingand the production segments of the olive oil chain.

After the filling-closing-labelling operation, a final automatic or visual control hasto be carried out to verify conformity of the packages, integrity of the containers,correct positioning of labels, and so on. Packages that do not conform to standardsare discarded, recycled and recovered or disposed of.

Page 6: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

184 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Packaging As Soon As Possible or As Late As Possible:ASAP or ALAP?

From the quality point of view, is it preferable to store the oil in tanks and tobottle it just before shipping it to the customers, or is it preferable to bottle theoil as soon as possible and store it in the bottles before shipping them to thecustomers?

If critical storage conditions are under control in both cases, the two optionscan be considered as equivalent but the risk of non-conformity is not the same.

Prevention of light exposure and photo-oxidation

In a stainless steel tank, protection from light is assured 100%; in a glass orplastic bottle this depends on the light shielding characteristics of the packagingmaterial. Unfortunately, this risk cannot be avoided during the marketing life ofthe bottled product and during exposure on the retail shelves. From this point ofview, the closer the oil is bottled before selling to the final consumer, the saferit is from light exposure and abuse.

Prevention of oxygen contact

In a stainless-steel tank, which is duly maintained under an inert atmosphere ata pressure slightly higher than atmospheric pressure, this risk is negligible. Therisk of oxygen permeating plastic containers is high. Glass and metal contain-ers guarantee suitable protection only if air is flushed from the headspace of thebottles and replaced with inert gas. Even in this case, however, the plastic com-ponents of the closure (including the pouring device) can be a risk for oxygenpermeation.

Prevention of temperature abuse

A storage tank and a bottle inside an air-conditioned storage room that is main-tained at the right storage temperature (15 ± 2 ∘C) have the same level of pro-tection from temperature abuse. The vulnerability to temperature changes is,however, very different and much higher in a bottle than in a tank for tworeasons:

• A bottle has a much higher surface-to-volume ratio than a tank and this meansa much higher heat transfer rate. It can be easily calculated that the surface-to-volume ratio in a cylindrical 0.5 litre bottle is about 30 times higher thanin a storage tank with a 5 m3 capacity.

• The total heat capacity of the oil contained in a tank is much higher than theheat capacity of the oil contained in a bottle. Being that the heat capacity isproportional to the mass, the comparison of the two situations presented aboveshows that the heat capacity of the oil in a 5 m3 tank is 10 000 times greater

Page 7: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.3 THE PACKAGING MATERIALS 185

than the heat capacity of a 0.5 litre bottle. This means that the same amountof heat has a negligible effect on the oil temperature in a tank, but a relevanteffect on the temperature of the oil in a bottle.

It is evident that temperature changes in the environment may be much moredetrimental to oil quality if the oil is in bottles than in tanks.

Both the tank and the bottle can be considered a safe protection from moistureor contaminants or micro-organisms from the environment.

In conclusion, oil should be stored in optimal conditions in bulk and bottled aslate as possible (ALAP) before the shipment date to customers. When in bottles,great care should be given to protect the bottles from natural or artificial lightand from temperature change.

16.3 The packaging materials

Packaging materials, including closing and pouring features that are in contact withthe oil, may influence its quality and shelf-life. Careful consideration should be givento the choice of the most suitable material considering the environmental conditionsand the shelf-life from packaging to consumption. A first crucial point is about con-sumer preference and the perception that consumers have about what is the mostsuitable container for extra-virgin olive oil. An investigation among regular con-sumers in Italy gave results that are summarized in Table 16.1 (elaborated fromEsposito 2012). A conventional value of 100 is given to the most preferred material(dark glass).

Despite scarce information and available knowledge, Italian consumers seem togive a sharply differentiated rating to their preference of packaging material. Prefer-ences may be different in different countries, but in any case this point has a decisiveinfluence on the choice of packaging material for extra-virgin olive oil.

For general works on packaging materials see Piergiovanni and Limbo (2010a, b),Pistouri et al. (2010) and Robertson (2010).

16.3.1 Glass bottles

Glass provides a total barrier to moisture and gases, including oxygen. However,glass bottles do have some weak points (Gawel 2010). Transparent glass and expo-sure to light (both in the UV and visible wavelength range) lead to photo-oxidation.

Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter thanthat of visible light – that is, lower than 400 nm. The ISO standard on determiningsolar irradiances defines Ultraviolet A (UVA) radiation between 400 and 315 nm,Ultraviolet B (UVB) radiation between 315 and 280 nm, and Ultraviolet C (UVC)radiation between 280 and 100. Radiation in the range of 400–300 is defined as‘near ultraviolet’.

Page 8: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

186 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Table 16.1 The preference scale of Italianconsumers for extra-virgin olive oil contain-ers (Source: Reproduced with permission fromAlessandro Esposito).

Container material Preference scale

Dark glass 100Clear glass 40Metal 30Plastic 0.7

Light in the UV region and in the visible region can contribute to oil oxidationthrough different pathways. The most harmful wavelengths are usually in the ultravi-olet part of the spectrum, just below the visible range, due to the high-energy content,which is capable of splitting certain chemical bonds. The shorter the wavelength, thehigher is the energy of light and the higher its oxidation-promoting effect.

The energy associated with the UV region can trigger the formation of free radi-cals, which play a fundamental role in the oxidative reactions. The visible region ofthe spectrum is characterized by wavelengths with low energy but it is also harmful,especially for oils and coloured beverages (Limbo et al. 2007). In fact, their sensi-tivity to light in this region is due to their pigment content, which is stimulated byquantas of the visible spectral region, acting as photosensitisers (Thron et al. 2001).The oxygen that is dissolved in the oil is ‘energized’ when hit by light and trans-formed into an active state, which is called singlet oxygen. In this form, oxygentriggers oxidative chain reactions leading to discoloration, off-flavour formation,rancidity and loss of antioxidants. For this reason, photosensitizing pigments likechlorophyll accelerate these phenomena. In general, the reaction rate of singlet oxy-gen with some food components is much greater than that of triplet oxygen. Singletoxygen can attack double bonds directly; its reactivity with linoleic acid is about1450 times faster than that of triplet state oxygen (Min and Boff 2002).

Many producers think that the darker the glass, the more effective it is inpreventing photo-oxidation. This is not true and the distinction between thelight-transmission properties of packaging materials in the UV and visible regionsare fundamental in determining the right protection for oils. Glasses with a lowtrasmittance (high absorption) of light in the UV range are the best for protectingoil from radical oxidation and this they can be made by adding special additivesin producing the glass. However, exposure to UV light during storage is not sofrequent, especially at the retail level, where the lamps used to display products arepoor in UV emissions. On the other hand, while displayed on sales shelves thesepackages are exposed to visible light that may impair oil quality.

Figure 16.2 shows the spectra of light transmittance of coloured glass (see Gawel,2010 and Piergiovanni and Limbo 2010a, Pistouri et al. 2010). The glass labelled‘flint’ is clear glass. By observing the spectra variation as a function of wavelength,it can be easily established that blue and emerald green glasses are very ineffectivein filtering the most dangerous UV light, in the range of UVA and near-UV. Dark

Page 9: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.3 THE PACKAGING MATERIALS 187

20

300

UVB UVA

400 500 wavelength, nm 600

Amber

Green

Tra

nsm

ittan

ce, %

Blue

Flint

40

60

80

100

Figure 16.2 Light transmittance of various collared glass (Source: Robertson, G.L., (1993).Reproduced with Kind permission from Taylor & Francis).

blue bottles are effective filters of visible light but this has a low protective effect onthe oil. The green colour and the dark green, similar to the colour of olives, have asimilar but slightly better performance. The brown amber bottles have the best light-protecting effect. The thickness of the glass wall has little influence on protectionfrom light.

Other weak points of glass are fragility and high specific weight, which presentproblems in handling and carrying. Glass fragility may lead to contamination of theoil by glass fragments. Automatic or visual inspection followed by air blowing justbefore filling should be considered as a critical control point.

Glass is a perfect barrier to gas and oxygen, but the polymeric closing and sealingmaterials can be considered as a minor risk to oxygen permeation.

Finally, temperature abuse can be a problem for glass bottles, especially if thecontrol of storing and transportation conditions in the commercial network is notsatisfactory.

From the environmental point of view, glass containers represent an almost idealrecyclable product; glass can be fully recycled when properly disposed of.

16.3.2 Metal containers

Metal containers are light in weight, have good mechanical resistance and are a totalbarrier to light and oxygen. They are made of tin plate or tin-free steel (TFS) basedon chromium instead of tin plate or also aluminium or aluminium alloys. The con-tainers are protected from corrosion by an internal coating with food grade enamels(lacquers).

Metal containers are supplied by the manufacturer top-bottom closed with onlyone orifice to be used for filling and capping or just bottom closed. The latter

Page 10: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

188 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

allows inspection and air blowing before filling, which is a useful precaution.Bottom-closed containers are closed with top installation after filling.

Metal containers reach the oil company ready for use and must be protected inthe original package for storage in a clean warehouse.

Metal containers are normally used in sizes from 1 to 20 litre. However, specialbrands have recently adopted metal containers as small as 0.1 litre.

Metal containers can be recycled, but corrosion of the internal coating is a limi-tation to reuse.

16.3.3 Plastic containers

Plastics are relatively new materials for the packaging of edible oils, but seldomused for extra-virgin olive oil. The polymers most frequently used are polyethy-lene terephthalate (PET), high-density polyethylene (HDPE) and polyvinylchloride(PVC). They have some advantages over metal and glass containers, namely a lowerprice, a lower weight and a higher mechanical resistance.

Polyethylene terephthalate, in particular, is receiving some attention for its bril-liance and transparency, enhancing the aesthetic appeal of the oil (Gawel 2010;Rizzo et al. 2013). However, plastic containers do not provide as long a shelf lifeas metal or glass. Their major drawbacks are scalping, migration of contaminants,oxygen permeability and light transmission.

Scalping consists in the absorption of volatile and nonvolatile components of theoil at the plastic surface with loss or reduction of desirable flavour compounds.

Migration of plastic additives, monomers or oligomers not chemically bound tothe polymer matrix may contaminate the oil. This is a serious safety threat and aviolation of olive oil legislation. Migration of acetaldehyde from PET bottles canseriously damage the sensory profile of the oil. Hydrophobic affinity of the oil andthe plastics greatly favours scalping and migration phenomena.

Oxygen permeability is a major limitation in the use of plastic containers for extra-virgin olive oil. Recent advances in the development of active packaging have ledto plastics, especially PET bottles, with ‘oxygen scavengers’ that not only avoidoxygen permeation from the outside, but also remove the dissolved oxygen in the oil.The action of the oxygen scavengers can be further potentiated by coating with high-barrier resin. Results seem to be encouraging, but consumers are still very reluctantto accept plastics as extra-virgin olive oil containers.

Light transparency is also a weak point of plastics. For instance, PET, which hasa very good filtering capacity in the wavelength range of UVB, is highly transparentto light in the UVA region. Built-in UV blockers could possibly assure satisfactorylight-filtering performance.

Plastic containers are the unique category of containers that can be manufactureddirectly at the oil factory, just before filling, using preformed pieces that are heatedand blown on site. This feature provides an extra guarantee against contamination ofsolid powder and particulates. Of course, preformed containers are also available andthey have the same safety/cleaning problem as glass and metal containers. Plastic

Page 11: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.4 THE PACKAGING OPERATION 189

containers can be easily recycled and incinerated, if properly collected and managed.They cannot be reused.

16.3.4 Bag-in-box (BiB) containers and dispensers

The bag-in-box is a container consisting of a strong bladder (a plastic bag) made ofseveral layers of metalized film or other plastic seated inside a corrugated paperboardbox. The bag is supplied to the filler as an empty pre-made bag. The filler removesthe tap, fills the bag and replaces the tap. The bags are available for semi-automaticmachines or for automated filling systems. There is also a version in which the bagsare manufactured online from reels of film and then the tap is inserted and finallyfilled in a rotary head filler. This technology is widely used with wine. The absenceof light is assured by the paperboard box.

Due to its collapsible characteristics, the plastic bag shrinks when the oil is pouredout so that the presence of air in the headspace is avoided. It must be noted, however,that oxygen permeates through the plastic and therefore, extra-virgin olive oil shouldnot be kept in a BiB for longer than 3 months.

In 3–5 litre containers, a built-in spigot allows the oil to be poured accordingto the needs of use or consumption in families and restaurants. The use of BiB asan oil dispenser allows the oil to be served at the table in portions, while keepingthe rest of the oil in the absence of air and at the optimal temperature. The ease ofprinting on the paperboard box allows attractive figures to be drawn and to give theconsumer suitable information. These features are fostering increasing success ofthe BiB system as an oil dispenser in restaurants and families (Monini SpA 2013).

16.3.5 The choice of the most suitable package

Packages of various sizes and material are generally used by extra-virgin olive oilcompanies, depending on customer needs, the use of oil, the marketing turnover,the conditions of storage and transportation. The decision about packages has verysignificant consequences on oil cost, as is clearly shown in Chapter 23.

Such a decision should take into account the most suitable characteristics in thedifferent cases. Table 16.2 presents a synthesis of some relevant aspects to be con-sidered in package selection and choice. The evaluation of suitability is very simplyexpressed as high, medium, or low.

16.4 The packaging operation

For general works on packaging operations see Piergiovanni and Limbo (2010a)and Robertson (2010). The packaging operation consists in the following seriesof steps: depalletization, decasing, cleaning, filling, closing, coding, fill checking,

Page 12: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

190 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Table 16.2 A qualitative comparison of performance of various materials for extra-virgin oliveoil packaging.

Package material performance Rating of suitability

Glass containers Metal containers Plastic containers

Reputation and consumerpreference

High Medium Low

Economy (minimum cost perunit quantity of oil)

Low Medium High

Protection from light Medium High LowProtection from oxygen High High LowRecycling/reuse possibility High Medium MediumMechanical resistance Low Medium HighLightness in weight Low High HighInertness (minimal release of

metal or plastic components)High Medium Low

Prevention of scalping High High LowHermetic sealing High High HighAccessibility for cleaning of

empty containersHigh Low Medium

Length of turnover periods(average time from packagingto oil use)

High High Low

labelling, final checking, casing and palletization. In highly mechanized andautomated systems, a well-planned operating rate of the various machines shouldassure smooth functioning of the entire packaging line. In particular, as filling isthe most important and the slowest step in the line, the preceding operations ofdepalletizing, decasing and cleaning should operate at a rate about 10% faster thanfilling so that stable feeding of containers is assured to the filler. Similarly, thefollowing steps, particularly closing and labelling, should also operate at a rateabout 10% faster than the filler so that filled containers do not accumulate at theexit of the filling station. Much less stringent rules are applied in semi-automatic ormanual operations of the packaging line.

Systematic cleaning of the various machines, especially the filler, should be car-ried out in order to avoid oil contamination or oil spoilage in dead spots of the circuitduring intervals from one filling operation to the following one. This is a criticalpoint in small factories, where long periods of time separate one packaging operationfrom another. Complete cleaning procedures with appropriate emptying, detergency,sanitizing, rinsing and drying should precede and follow each packaging operation.

The most important requirements in extra-virgin olive oil packaging are:(i) flexibility, which is the ability to use the same filling-closing-labelling machinesfor containers of various forms and sizes; and (ii) precision in filling of prede-termined weights or volumes because underfilling raises legal problems whileoverfilling causes economic losses.

Page 13: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.4 THE PACKAGING OPERATION 191

A good rule is to set the average fill weight or volume at least three standarddeviations above the declared value on the label. Setting the average fill three stan-dard deviation above the declared value on the label gives a probability less than0.13% of amounts less than the declared quantity on the label. In large-scale pro-duction, statistical process control must be adopted with frequent checking of properfilling performance.

Packaging lines can be organized as straight-line or rotary configurations. Thelatter are generally used in high capacity lines. A wider diameter of the rotatingturret, with a higher number of filling valves, operates at higher filling speed.

16.4.1 Bottles filling

The filling of extra-virgin olive oil in bottles is generally based on a predeterminedlevel in the container. A critical condition in oil packaging is to avoid any shaking orturbulence and aeration during filling because air mixing spurs oil oxidation. Tem-perature variations should be avoided because they determine viscosity variationswith fluctuation of the filler performance. Also, too low a temperature of the oilshould be avoided during filling because a subsequent increase in temperature cancause oil expansion and improper pressure on the closure. The best would be to havea temperature of 20 ∘C (±1 ∘C) during the packaging operation, before sending thebottled oil to a storage room at 15 ∘C (±2 ∘C).

The two systems most commonly used in filling extra-virgin olive oil in glassbottles are pure gravity filling and vacuum filling to a constant predetermined level.Figure 16.3 shows the functional scheme of pure gravity filling.

A spring-loaded sleeve valve consists of two concentric tubes, the outer one forthe downward flow of the oil from the oil supply tank into the bottle and the innertube for venting air from the bottle during filling. The valve opens when the bottleis pushed up into the sealed position against spring pressure. The oil flows downwithout turbulence along the bottle wall. When the air vent tube is reached by theoil level, the flow stops because the residual air cannot escape from the containerand thus no further liquid can flow into the container. At that point the container islowered and disengaged from the valve that automatically closes the oil outlet. Puregravity fillers are easy to clean and operate both in automatic and manual machines.They are also very accurate.

In other plants, level sensing fillers trigger a control system that shuts down theoil flow at the predetermined level. In this case there is no need to seal the containerby pressing it against the filling valve. This system can therefore also be used forplastic containers. Figure 16.4 shows the functional scheme of pure vacuum filling.

A filling valve sealing against the bottle neck connects the bottle with two lines:a feeding line coming from the supply tank, which is at atmospheric pressure, and avacuum line connected to a vacuum pump through a vacuum chamber. The vacuumin the bottle sucks the oil from the supply tank until the oil level reaches the vacuumport in the filling valve. This is the constant level of oil in the bottle. The overflow ofoil goes to the vacuum chamber and is recycled to the supply tank. Vacuum filling is

Page 14: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

192 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Air outlet

Feeding sleeve

Air vent

Flow of the oil alongthe bottle wall

Spring-loaded sleevevalve

Fill level

Seal

Figure 16.3 The functional scheme of pure gravity filling (Source: Lee, D.S. et al. (2008).Reproduced with Kind permission from Taylor & Francis).

Feeding line Vacuum lineand over-flowrecycling

Seal

Figure 16.4 The functional scheme of vacuum filling (Source: Lee, D.S. et al. (2008). Repro-duced with Kind permission from Taylor & Francis).

Page 15: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.4 THE PACKAGING OPERATION 193

faster than gravity filling and prevents cracked or defective bottles from being filledbecause of the impossibility of obtaining a vacuum in the bottle.

This system cannot be used for plastic containers because they are not rigidenough to withstand the vacuum.

16.4.2 Bottles closing

Closure should provide hermetic sealing of oil bottles. Closure of extra-virgin oliveoil bottles should also include pouring and tamper-evident devices.

Tamper-evident is a device that makes unauthorized opening of the bottle or pack-aging easily detected. Tamper-evident design can be vital for the consumer to knowthat the product has not been altered since it left the manufacturer. Consumers shouldbe educated to watch for signs of tampering.

In order to ensure the authenticity of extra-virgin olive oil, the EU is consideringthe possibility of requiring the mandatory use of nonrefillable containers for extra-virgin olive oil in hotels, restaurants and cafes. These are containers with closuresthat cannot be removed without breaking.

In bottling extra-virgin olive oil, threaded closures are generally used. They areput on and taken off by screwing on the mouth of the bottle. Both application andremoval torque are important.

Torque is the tendency of a force to rotate an object about an axis. Mathematically,torque is the cross product of the lever-arm distance and the force which tends toproduce rotation. Torque is a measure of the turning force needed to apply a capto the bottle (application torque) and the force needed to twist off the cap (removaltorque). A removal torque that is too low presents a risk of accidental looseningof the closure, whereas a torque that is too high causes difficulty in opening thecontainer.

An effective protection from oxidation is nitrogen flushing and air removal fromthe head space in the bottle neck just before cap installation. This is particularlyuseful if the oil has been effectively degassed as, for example, in vacuum filling.

The most common closure for glass bottles of extra-virgin olive oil are screw caps,also called continuous thread cap, and roll-on cap.

Screw or continuous thread (CT) caps

Screw cap closures attain a seal with the bottle by engagement of its thread with thecorresponding threads of the bottle neck. Screw caps are tinplate or tin-free steelor aluminium. Hermetic sealing is due to close contact between the closure and thebottle mouth. A resilient liner compressed between the closure and the bottle mouthprovides a tight and secure fastening (Figure 16.5).

Liners consist of backing and facing materials. Backing materials are soft andelastic to provide cushioning under compression. Facing materials should have an

Page 16: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

194 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Knurling Liner

Threading

Bridges

Tamper-evident band

Figure 16.5 A section view of a screw cap (Source: Lee, D.S. et al. (2008). Reproduced withKind permission from Taylor & Francis).

adequate barrier property and should combine closely and tightly with the pouringdevice that is mounted on the bottle mouth.

An oxygen-absorbing liner may be inserted into the cap to protect the oil fromoxygen diffusion and permeation from the outside atmosphere.

The lower part of the cap skirt is linked through bridges to the cap body andseparates when the cap is twisted for opening. Tamper-evidence is given by breakingof the bridges and the drop-down band may remain on the bottle neck as evidenceof tampering.

Roll-on caps

A roll-on closure is formed into final shape by the pressurized rolling of the pre-formed aluminium shell onto the bottle threads. A top pressure assures the sealbetween the container finish and lining compounds of the cap. A breakable skirtfor tamper-evidence is similar to continuous thread closure. The closing operationis commonly achieved by a chuck that grips the closure and turns pushing it intothe desired position. The capping head tightens the closure until the desired torqueis reached.

16.4.3 Labelling

Labelling is one of the most controversial issues of extra-virgin olive oil marketing.This presentation is based on European legislation (Commission Regulation (EC)

No 182/2009 amending Regulation (EC) 1019/2002 on marketing standards forolive oil, and Commission Implementing Regulation (EU) No 29/2012 on marketingstandards for olive oil), which is a reference for legislation on olive oil worldwide.

Page 17: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.4 THE PACKAGING OPERATION 195

The discussion about labelling is divided in two parts: the first one concerns themandatory information on the label and the second concerns the voluntary informa-tion that can be put on an olive oil label.

Mandatory information on the label

The labelling of olive oil must bear ‘in clear and indelible lettering’ the name of thecategory of the oil, based on technology and analytical/sensory standards. One ofthe following denominations should appear on the label:

• ‘Extra-virgin olive oil’ together with the following information: ‘superiorcategory olive oil obtained directly from olives and solely by mechanicalmeans’. This oil has a maximum free acidity, in terms of oleic acid of 0.8%,and the other characteristics that comply with those laid down for this category(Chapter 2).

• ‘Virgin olive oil’ together with the following information: ‘olive oil obtaineddirectly from olives and solely by mechanical means’. This oil has a maximumfree acidity, in terms of oleic acid of 2.0%, and the other characteristics whichcomply with those laid down for this category (Chapter 2).

• ‘Olive oil composed of refined olive oil and virgin olive oils’ together with thefollowing information: ‘oil comprising exclusively olive oils that have under-gone refining and oils obtained directly from olives’. This oil has a maximumfree acidity, in terms of oleic acid of 1.0%, and the other characteristics whichcomply with those laid down for this category (Chapter 2).

• ‘Olive pomace oil’ together with the following information: ‘oil comprisingexclusively oils obtained by treating the product after the extraction of olive oiland oils obtained directly from olives’. This oil has a maximum free acidity,in terms of oleic acid of 0.3%, and the other characteristics that comply withthose laid down for this category (Chapter 2).

The other mandatory information on the labels is:

• the name under which the oil is sold;

• the net quantity;

• the date of minimum durability;

• the name or business name and address of the producer;

• the number or code of the identity and traceability of the oil.

The name under which the oil is sold, the net content and the traceability codeshould be in the same visual field.

In Europe and in many other countries, the size allowed for containers destinedto the final consumer is established by law.

Page 18: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

196 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Table 16.3 A series of examples of solutions and difficulties in the labelling of extra-virginolive oil.

Claims Comments about their trustworthiness

Claim about the origin The origin of olives and oil is important information from theconsumer’s point of view. Origin means tradition, biodiversity,oil-culinary connections, and a specific sensory style. Origin cannotbe identified with certainty by analysing the oil. It can only beidentified through a combined system of documented balance ofmaterial lots and the analytical finger-printing of each lot.

European Union legislation provides a very detailed definition of thedifferent cases of designation of origin, from the ProtectedDesignation of Origin (PDO) of oils from areas or regions to blendsof oils from the same EU country or from various EU countries andalso blends of olive oils of EU and non-EU origin.

No claims of territorial origin are allowed in Europe outside this legalframe.

Claims about thecultivar(s)

In principle, these claims are not allowed in the EU legislation, unlessthey refer to the cultivars formally defined in the PDO regulations.This is a serious gap of information for consumers because cultivarsare the most effective and appealing image of biodiversity.

A cultivar cannot be identified with certainty by analysing the oils. Itcan only be identified through a combined system of documentedbalance of material lots and the analytical fingerprinting of eachoil lot.

Claims about sensorycharacteristics

The Commission Implementing Regulation No 29/2012 allowsindications concerning the sensory properties referring to tasteand/or smell of the oil to be written on the label of extra-virginolive oils. This must be done by using the terms set up by the lawand assessed by applying the method provided by the law.

Extra-virgin olive oil is an unusual case in which sensory perceptionsmust be described according to a predefined and mandatoryglossary of sensory notes.

Claims about chemicalstandards

The indication of maximum acidity may appear on the label only ifaccompanied by an indication, in lettering of the same size and inthe same visual field, of the peroxide value, the wax content and theultraviolet absorption determined according to the official methodsof analysis (Commission Regulation (EC) No 182/2009 amendingRegulation (EC) 1019/2002 on marketing standards for olive oil).

Claims about theharvest date

Product freshness is an important feature of oil quality andexcellence, but claims of harvest date are not allowed. This is aclassic case in which the concern to avoid deceiving the consumerdeprives him/her of useful information.

The harvest date cannot be identified with certainty by analysing theoils. It can only be identified through a combined system ofdocumented balance of material lots and the analyticalfinger-printing of each oil lot.

(continued overleaf )

Page 19: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

16.4 THE PACKAGING OPERATION 197

Table 16.3 (continued)

Claims Comments about their trustworthiness

Claim of ‘cold extraction’ According to the EU legislation, the claim ‘cold extraction’may appear only for extra-virgin olive oils obtained attemperatures below 27 ∘C (80.6 ∘F). This is a good exampleof how bad the result can be of an over-regulating system. Inthe first place, there is no evidence that 27 ∘C is better than30 ∘C or 32 ∘C. It is just another limitation of the producersto experimenting for optimization. In the second place, thereis no way to convey to consumers the perception that 27 ∘Cis ‘cold’ while 30 ∘C is ‘too warm’. In the third place, sayingthat an oil has been obtained by ‘cold extraction’ leads theconsumer to think that there must be some kind of a ‘hotextraction’, which, in fact does not exist. Finally, controllingand certifying the process conformity to this requisite is verydifficult or impossible if normal temperature control devicesare used.

Claims of ‘nonfiltered oil’ Oddly enough, the legislation has no objections to this claim,which is, in fact, misleading to the consumer because it leadsto the understanding that filtration is detrimental to oilquality, while the opposite is true. On the other hand, what isthe sense of writing something when it is self-evident fromthe turbidity of the oil?

Suggestions about storageconditions

This critical information for oil quality should hopefullybecome mandatory and be well evidenced on the label.

Good readability Overloading a label with excessive information and analyticaldata written in microscopic characters could be consideredanother way of misleading the consumer. Too muchinformation dangerously borders on not enough.

Nutritional information The information about the nutritional content and profileshould be given according to precise legal indications. Itmay concern the energetic and major nutrient content as wellas figures of mono and polyunsaturated fatty acids, vitamins(such as, for instance, α-tocopherol). Minimum content isoften prescribed or included in label information. (SeeRegulation (EU) No 1169/2011).

Other information Whereas No 12 of the Commission Implementing RegulationNo 29/2012 says that ‘all other indications appearing on thelabel should be corroborated by objective elements in orderto ensure that consumers are not misled and that competitionon the markets in the oils concerned is not distorted’.Phenolic content can probably be considered as complyingwith this requirement.

Page 20: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

198 CH16 EXTRA-VIRGIN OLIVE OIL PACKAGING

Voluntary information on the label

It is evident that the mandatory information listed earlier gives only limited informa-tion about the product characteristics and properties. It is therefore understandablethat producers and retailers would like to give more detailed information about theprocess and the product and this is the point that causes most of the confusion anddebate. The problem is that many claims creating important consumer appeal andmarketing effectiveness are difficult (and sometimes impossible) to demonstratethrough reliable analytical means. As a consequence fraud is not detectable. Thishas caused the creation of compulsory rules, either too rigid or too restrictive, witha hindering effect on simple and clear communication to the consumer.

The rationale for the European legislation is clearly explained in the ‘whereas’section, point 10 of the Commission Regulation 29/2012:

indications shown on the labelling should not mislead the purchaser, particularly asto the characteristics of the olive oil concerned, or by attributing to it properties whichit does not possess, or by suggesting that it possesses special characteristics when infact most oils possess such characteristics.

This point, which is important and can be shared by everyone, leads the legislatorto express the following concept:

Certain commonly used, optional indications that are specific to olive oil also requireharmonized rules to precisely define such claims and ensure that their accuracy canbe verified …

This wise proposal contains a serious risk: that an agreement on ‘harmonizedrules’ could never be attained and that important claims in the consumer’s interestand wishes would never be allowed.

Some of the controversial issues about labelling of extra-virgin olive oil are sum-marized in Table 16.3.

References

Esposito, A. (2012) La nuova legislazione del settore dell’olio extra vergine di oliva:analisi empirica degli effetti sulle preferenze dei consumatori italiani, PhD Thesis,University of Udine.

Gawel, R. (2010) Are All Dark Glass Bottles Used for Storing Extra Virgin OliveOil the Same? http://www.aromadictionary.com/EVOO_blog/?p=357 (accessed11 October 2013).

Limbo, S., Torri, L. and Piergiovanni, L. (2007) Light-induced changes in an aque-ous beta-carotene system stored under halogen and fluorescent lamps, affectedby two oxygen partial pressures. Journal of Agricultural and Food Chemistry 55,5238–5245.

Page 21: The Extra-Virgin Olive Oil Handbook (Peri/The Extra-Virgin Olive Oil Handbook) || Extra-virgin olive oil packaging

FURTHER READING 199

Min, D.B. and Boff, J.N. (2002) Chemistry and reaction of singlet oxygen in foods.Comprehensive Reviews in Food Science and Food Safety 1, 58–72.

Monini SpA (2013) La nuova Bag in Box di Monini – Dieci litri d’olio, nientesprechi, www.italiaatavola.net/articolo.aspx?id=24757 (accessed 11 October2013).

Piergiovanni, L. and Limbo, S. (2010a) Food Packaging – materiali, tecnologie equalità degli alimenti, Springer Verlag, Milan.

Piergiovanni, L. and Limbo, S. (2010b) Packaging and shelf life of vegetable oils, inFood Packaging and Shelf Life – A Practical Guide (ed. G.L. Robertson), CRCPress, Boca Raton, FL.

Pistouri, G., Badeka, A. and Coutominas, M.G. (2010) Effect of packaging mate-rial headspace, oxygen and light transmission, temperature and storage time onquality characteristics of extra virgin olive oil. Food Control 21, 412–418.

Rizzo, V., Torri, L., Licciardello, F. et al. (2013) Quality changes in extra virginolive oil packaged in coloured PET bottles stored under different lighting condi-tions. Packaging Technology and Science http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291099-1522/earlyview (accessed 11 October 2013).

Robertson, G.L. (ed.) (2010) Food Packaging and Shelf Life – A Practical Guide,CRC Press, Boca Raton, FL.

Thron, M., Eichner, K. and Ziegleder, G. (2001) The influence of light of differentwavelengths on chlorophyll-containing foods. Lebensmittel – Wissenschaft undTechnologie 34, 542–546.

Yam, K.L. (ed.) (2009) Wiley Encyclopedia of Packaging Technology (3rd edn), JohnWiley & Sons, Inc., New York.

Further reading

Lee, D.S., Yan, K.L. and Piergiovanni, L. (2008) Food Packaging Science and Tech-nology, CRC Press, London.

Mendez, A.I. and Falqué, E. (2007) Effect of storage time and container type on thequality of extra-virgin olive oil. Food Control 18(5), 521–529.


Top Related