App for orange sorting, process, pack or bottle, value add (orange juice manufacture), and full orange sales, inventory, QC, orange export management.

Improve orange packing speed, reduce orange waste, easy pack to order & 100% accurate shipping/export.

Orange packing app.

Software app for Food Service Fresh Produce packing : grading, sorting, and processing. Includes export, wholesale, and full packing management app. Built around traceability & recalls: bar-code inventory, B2B Customer Portal, Shop front, FARM MANAGEMENT OPTION and more... Farmsoft provides complete management for onion packing, broccoli packing, citrus packing, pepper packing, tomato packing, avocado packing, potato packing. Salad packing, Loose leaf lettuce and other fresh produce such as spinach, rucola, chicory, watercress. Cucumber packing. Citrus packing app for lemon, orange, mandarin, tangerine, clementine. Asparagus packing. Onion inventory & storage. Potato inventory storage app. Potato traceability app for better packing & logistics. Onion traceability management. Carrot packing app for traceability & inventory control. Bean packing solution. Mango packing app for traceability. Leafy greens packing, processing, washing, mixing leafy greens salads packing. Seafood packing app for packers and processors of fresh and IQF seafood: full seafood inventory, traceability, seafood quality control, orders, sales, seafood shipping import/export. Fresh cut packing app manages entire fresh cut fruit & vegetable processing, washing, sorting, cutting, chopping, and packing. Full inventory, traceability, and sales & shipping management. Food Service Fresh Produce Processing and packing app manages entire fresh cut, value add, fries & chips, coleslaw and salad mixing process for food service businesses. Coleslaw manufacturing & packing app: manages full coleslaw mixing and packing process: program coleslaw recipes, reduce fresh produce waste, and manages production & sales.  Wash, treat, sort grade and pack bananas for export/import.  App for orange sorting, process, pack or bottle, value add (orange juice manufacture), and full orange sales, inventory, QC, orange export management.


Manage incoming Orange packing inventory & storage inventory, capture supplier details, traceability and costs (optionally capture on PO in advance), create inventory & pallet labels, record storage location of inventory.  Automatic inventory audit trail and tracking.  Unlimited inventory items. Bar-code inventory management.


Perform stock-takes any time by category or storage location.  Know how much Orange inventory you have in real time, even search by storage location.  Report by product line and storage location, or product category. 

ORANGE FARM Management

Full farm record keeping, activity management, best practices, budgeting, time-sheets, machinery costs, inventory, cherry farm traceability, PHI/WHP management, and more... 

Sales, shipping,  orders

Print pick sheet to pick Seafood inventory & storage orders manually, or scan inventory / pallets onto orders, or auto select inventory,  or rapidly sell without an order.  Track paid, and unpaid invoices.  Attach documents to invoices / photos of outgoing shipments.

Traceability & recalls

Instant mock recalls both up and down the supply chain using keys based on supplier lot/batch, supplier name, delivery date, invoice #, inventory #, pallet #, customer reference, order # and more...  Reduces fresh produce food safety compliance costs and makes audits easy. Optional fresh produce blockchain by CHAIN-TRACE.COM

Invoices, BOL, labels for pallets & inventory

Choose from a gallery of invoices, bill of lading, freight notes, and industry standard fresh produce labels including Walmart, Tesco, Aldi, Coles, Pick 'n Save, Woolworths and more...

Batch packing

Record all batch inputs such as fruit & vegetables, packaging materials, and other raw materials.  Batch costs automatically tracked.  Batch recalls automatically track suppliers & traceability.


View open orders & balances. Assign orders to specific staff for picking, assign to trucks / driver, transport company.  Set loading order for multiple orders on one truck.  See when orders are ready shipped and print bill of lading, export documents, and invoices. 

Quality control

Perform QC tests for incoming pepper inventory, packed, pre-shipping. Configure QC tests for ANYTHING you want to test, supplier quality control tracking.  Attach unlimited photos & documents to QC tests from your cell or tablet.  

Price lists

Manage prices that will be used when a customer order is recorded.  Set up price lists for specials, specific products & customers or promotions.  


Profit:  Analyze profit of each onion line, variety, and even track individual customer profit, and batch level cost & profit.  Sales:  Monitor sales progress & shipments.  Quality:  supplier performance & more...


Auto shipment and sale alerts to customers.  Configure BOM, packing / manufacturing processes, special rules to control the processes in your business (your consultant will do this for you).   

Value adding

For food service and processors:  specify the ingredients for each product you manufacture, farmsoft will calculate required quantities to fill open orders and schedule the batch.  Automatic creation of inventory outputs.  All ingredients and inputs are costed.

Unlimited sites & warehouses

Create multiple sites, specify which sites each employee can view (this restricts inventory, orders, invoices etc to selected sites).  Great for businesses with multiple locations across the country or planet.

Advanced tailoring

Add new fields to screens, choose from a wide selection of interfaces (touch based, PC based, data entry, tablet), control special business processes, activate defaults, configure automatic alerts and more...

Purchase orders

Order raw materials, packaging materials and more from suppliers.  Analyze orders and prices using Purchases dashboard. 

Re-order alerts

Receive alerts when inventory needs to be reordered, analyze inventory that will need ordering in the future, and inventory that is approaching expiry...

Finance apps

Integrate with Xero finance, or export invoices (AR) and Purchase Orders (AP) to your chosen finance app like MYOB, Quickbooks, , FreshBooks, Wave, SaasAnt, SAGE and others...

Reduce Orange  packing waste by 99%

Packing inventory control ensures there is no 'shrinkage', food inventory is FIFO managed, and expiring inventory always monitored.

Reduce Orange administration time by 60%

Automatic paperwork for packing, labels, and reporting reduces the burden on administration teams and saves everyone's time.

Better Orange packing quality now

Quality control and food safety has never been easier with industry standard quality tests, food safety checklists; or configure your own tests. 

100% accurate Orange packing orders!

Guarantee only the correct inventory is shipped for each order, on time, every time.

Easy Orange packing & storage

Perform instant mock recalls and audits at any time, from anywhere. No need to compile reports or search for documents. International food safety standards maintained.

Reduce Orange packing  & storage inventory stocking costs by 10%

Project required ingredients & materials to ensure just in time delivery and reduce inventory overheads & waste.

Faster Orange packing  inventory control

Know exactly which inventory is available, where it is, and when it expires:  any-time, anywhere.
No need to manually create reports in spreadsheets, instant real time access to your inventory details.

100% accurate Orange packing production management

Rapidly assign customer orders to production batches, line & inventory managers receive instant alerts.  Precision processing & packing reduces fresh produce waste.

Oranges (Citrus sinensis) belong to the rue family (Rutaceae) and come originally from southern China.

In addition to oranges, the group of citrus fruits, which are mainly cultivated in subtropical regions, also includes lemons, grapefruits, mandarins, limes and easypeelers. Easypeeler is the name given in particular to crosses between oranges and mandarins whose peel is very easy to remove.

Citrus fruits are berry fruit consisting of three layers:

the outer yellow/orange peel (exocarp, flavedo), the glands of which exude the essential oils, which produce the typical citrus odor
the whitish mesocarp (albedo)
the endocarp consisting of 8 – 10 segments filled with juice sacs (vesicles)

Oranges, as is usual for citrus fruit, are most significantly classed by seasonal availability:

winter oranges from the countries of the Mediterranean from November to June
summer oranges from overseas countries from June to November

Oranges are also divided into early, middle and late ripening varieties. The varieties also sometimes share a typical fruit color, a distinction being drawn between blond, blood and late oranges. Navel oranges are the most important variety of blond oranges. Blood oranges are subdivided into deep blood oranges (peel and pulp red) and light blood oranges (peel with or without slight red coloration, pulp red).

The degree of ripeness of citrus fruit is determined on the basis of three criteria:

by the ripeness index: this is determined by the Brix value, which is a measure of the sugar/acid ratio of the fruit. According to [7], citrus fruit with a Brix value of between 10 and 16 have good flavor.
by cutting at purchase: freshness is determined by cutting the fruit in half from the stem-end to the opposite end. If the fruit is withered at the stem-end, it must not be shipped.
by peel color: the color of the peel is not necessarily a reliable indicator of ripeness, but its surface gloss is.

Fungicides are diphenyl, orthophenylphenol (OPP) and thiabendazole (TBZ). Diphenyl can be recognized from its naphthalene-like odor. The fungicides primarily prevent blue and green molds, but they do impair flavor and indication of their use is mandatory.

Quality / Duration of storage

Experience has shown that it is the care taken with preparation of the fruit for shipping which very largely determines whether individual batches withstand the rigors of transport. Such preparation for shipping is carried out in packing houses. These include:

Post-ripening of green or unsatisfactorily colored fruit to achieve a salable peel color in ripening rooms.
Removal of dirt, sooty mold, spraying residues and scale insects in washers.
Finishing of oranges which do not develop the typical orange color, but instead remain pale gold, green or with green spots, in a dye bath at temperatures of 45 – 50°C. Fruit treated in this way must be marked accordingly with a stamp (color added).
Coating with a layer of wax and treatment with preservatives and marking accordingly.
Grading of the fruits by size (gaging), color and other external features.
Counting, weighing and packing. Marking each package with details of number of fruit, quality class, variety and origin.
Storage until shipment in cold stores.

Waxing to prevent loss of aroma and weight is required because the washing process removes the natural wax layer. The film of wax sprayed onto the peel only partially seals the pores so that the fruits are still able to respire.

Maximum duration of storage and transport is as follows:

Designation Temperature Rel. humidity Max. duration of storage Source
6 – 10°C 85 – 90% 16 weeks [5]
Navels from Spain 3°C 85 – 90% 8 – 10 weeks [39]
Navels from California 7.2°C 85 – 90% 4 – 8 weeks [39]

Where controlled atmosphere transport is used, transport and storage duration may be extended. The following parameters apply in such a case [16]:

Temperature Rel. humidity O2 CO2 Suitability for controlled atmosphere
1.1 – 7.2°C (depending upon variety) 85 – 90% 10% 5% Moderate

Intended use

Oranges are mainly eaten fresh. They are also used in the production of orange juice, preserves and jams or in salads etc..


(Click on the individual Figures to enlarge them.)

Photo, orange treePhoto, orange tree

Figure 1
Drawing, orange

Figure 2 Photo, orange

Figure 3
Photo, navel orange

Figure 4 Photo, blood orange

Figure 5

Countries of origin

This Table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.

Europe Turkey, Spain, Italy, Cyprus, Greece
Africa South Africa, Algeria, Morocco, Egypt
Asia Israel, Lebanon, China
America Brazil, Argentina, USA , Mexico
Australia Australia

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Oranges are mainly transported in cartons, standard boxes, half-boxes, wire-bound boxes and fruit crates made of corrugated board or wood. They are sometimes also transported in net bags.

Photo, packaging

Figure 6 Photo, protective paper

Figure 7

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Symbol, general cargo

General cargo


Means of transport

Ship, aircraft, truck, railroad

Container transport

Refrigerated container with fresh air supply or controlled atmosphere.

Cargo handling

Because of its impact- and pressure-sensitivity, the fruit has to be handled with appropriate care.

The required refrigeration temperature must always be maintained, even during cargo handling.

In damp weather (rain, snow), the cargo must be protected from moisture, as there is otherwise a risk of premature spoilage.

Stowage factor

2.00 m³/t (corrugated board cartons) [1]
2.37 – 2.51 m³/t (boxes) [11]
1.67 – 1.81 m³/t (cartons) [11]
2.55 – 2.83 m³/t (boxes and cartons) [14]
2.50 m³/t (cartons on pallets) [39]

Stowage space requirements

Cool, dry, good ventilation


Fiber rope, thin fiber nets, wooden dunnage

Cargo securing

Because of its considerable impact- and pressure-sensitivity, packages of this cargo must be secured in such a way that they are prevented from damaging each other. Spaces between packages or pallets must be filled, to prevent slippage or tipping. By selecting the correct packaging size or cargo unit (area module or area module multiple), holds can be tightly loaded (without spaces).

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Risk factors and loss prevention

RF Temperature

Oranges require particular temperature, humidity/moisture and ventilation conditions (SC VII) (storage climate conditions).

A written cooling order must be obtained from the consignor before loading is begun. This order must always be complied with during the entire transport chain.

The following Tables merely constitute an estimate of appropriate temperature ranges. Temperatures may deviate from these values, depending on the particular transport conditions.

Designation Temperature range Source
Travel temperature 5°C [1]
6 – 10°C [5]
4 – 4.5°C [14]

The cargo and holds/containers should be precooled prior to loading.

During loading, pulp temperature measurements must be performed continually. The pulp temperature must never be < 4°C or > 25 – 30°C as storage life and appearance are impaired outside this range. Fruits punctured for pulp temperature measurement must be discarded as they would rapidly spoil and infect the other fruit. The measurements must be recorded.

Depending upon the species and variety, all citrus fruits are highly cold-sensitive. Grapefruit, lemons and limes are more susceptible to chilling damage than are oranges and mandarins, and late-ripening varieties are more temperature-sensitive than early varieties. While oranges can withstand temperatures of 5°C, more temperature-sensitive types should never be shipped below 10°C. Green citrus fruits require higher transport temperatures than do yellow; the higher is the acid content of the fruit, the greater is its cold-sensitivity.

Chilling damage is manifested in citrus fruits in particular by spots on the peel (brown dots on the peel), accompanied by a bitter taste and unpleasant odor, rot and cell wall collapse. The glossiness of the peel is lost and the albedo layer (inner layer of the peel), which is normally white, turns a dark color. When the fruit is divided up, the segments, which have a low juice content, break up and the whole fruit is glassy and soft. The severity of the chilling damage is determined not only by the extent to which the temperature has fallen beneath the limit, but also by the length of exposure to this temperature. Chilling damage does not generally occur in cold stores, but instead prior to cooling or after leaving the cold stores.

Excessively rapid warming of refrigerated fruit results in condensation and spoilage.

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RF Humidity/Moisture

Oranges require particular temperature, humidity/moisture and ventilation conditions (SC VII) (storage climate conditions).

Designation Humidity/water content Source
Relative humidity 85 – 90% [5]
85 – 90% [6]
85 – 90% [14]
85 – 90% [39]
Water content approx. 86% [1]
Maximum equilibrium moisture content 85% [1]

It is essential to protect oranges from moisture (seawater, rain, condensation, snow) as moisture in particular promotes green and blue mold and black rot.

In general, due to the high water content of citrus fruit of approx. 86%, a relative humidity of 85 – 90% is required. Only lemons, oranges and mandarins with a dark green peel color are able to withstand a relative humidity of 82 – 85%.

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RF Ventilation

Oranges require particular temperature, humidity/moisture and ventilation conditions (SC VII) (storage climate conditions).

Recommended ventilation conditions: circulating air, 40 – 60 circulations/hour with continuous supply of fresh air

The addition of fresh air is extremely important as citrus fruit can start to ferment within a few hours due to anaerobic respiration (resulting in total loss of the fruit). If ventilation is inadequate, storage damage may occur, taking the form of a bitter flavor and peel scab.

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RF Biotic activity

Oranges display 2nd order biotic activity.

They are living organs in which respiration processes predominate, because their supply of new nutrients has been cut off by separation from the parent plant.

Care of the cargo during the voyage must be aimed at controlling respiration processes (release of CO2, water vapor, ethylene and heat) in such a way that the cargo is at the desired stage of ripeness on reaching its destination. Inadequate ventilation may result in fermentation and rotting of the cargo as a result of increased CO2 levels and inadequate supply of atmospheric oxygen (see Ventilation).

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RF Gases

CO2 evolution at 5°C: 7.9 mg/kg*h
Upper limit of permissible CO2 content 0.3 vol.% [1]

0.1 vol.% [14]

0.5 vol.% [39]
Ethylene evolution
Active behavior The rate of ethylene production is very low, being below 0.1 µl/kg*h [16].
Passive behavior Oranges are moderately sensitive to ethylene [16] and should thus not be stored with goods having an elevated ethylene production rate (allelopathy).

In fresh fruit, metabolic processes continue even after harvesting. The fruit absorbs oxygen (O2) and excretes varying amounts of carbon dioxide (CO2) and ethylene (C2H4) as well as aromatic compounds during the ripening process.

If ventilation has been inadequate (frost) or has failed owing to a defect, life-threatening CO2 concentrations or O2 shortages may arise. Therefore, before anybody enters the hold, it must be ventilated and a gas measurement carried out. The TLV for CO2 concentration is 0.49 vol.%.

Levels of respiratory gases which promote ripening, such as ethylene as well as carbon dioxide, should be kept as low as possible. If ventilation is inadequate, storage damage, such as a bitter flavor and peel scab, may occur. The supply of fresh air must thus be constant in order to dissipate these gases.

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RF Self-heating / Spontaneous combustion

No risk.

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RF Odor

Active behavior Oranges have a strong, pleasant odor, this being a typical citrus odor caused by the essential oils in the flavedo layer of the peel. For this reason, they constitute a highly odor-contaminating cargo and must thus not be stowed or stored together with fruit, vegetables and other odor-sensitive foodstuffs. Meat, butter, eggs, fats and cheese are particularly prone to absorbing the citrus odor. Cold stores must therefore be carefully deodorized before different goods are transported on the next voyage. Wooden dunnage tainted with the citrus odor must not be reused for odor-sensitive goods.
Passive behavior Oranges are highly odor-sensitive.

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RF Contamination

Active behavior Oranges do not cause contamination.
Passive behavior Oranges are sensitive to dust, dirt, fats and oils. The holds or containers must accordingly be clean and in a thoroughly hygienic condition before loading.

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RF Mechanical influences

Oranges are highly impact- and pressure-sensitive. When transported in net bags, the fruit may be deformed by the excessive stacking pressure. If injury occurs, spoilage follows. Squashed areas take on the appearance of „goose pimples“ and the fruit becomes soft within a few days.

Attention must be paid to the level of filling of cartons in order to avoid damage: they should be filled no higher than the top as overfilling will inevitably result in pressure damage, and thus premature spoilage, when the cartons are stacked.

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RF Toxicity / Hazards to health

If ventilation has been inadequate (frost) or has failed owing to a defect, life-threatening CO2 concentrations or O2 shortages may arise. Therefore, before anybody enters the hold, it must be ventilated and a gas measurement carried out. The TLV for CO2 concentration is 0.49 vol.%.

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RF Shrinkage/Shortage

The normal weight loss due to a reduction in the moisture content of the product is approx. 1 – 2% [1].

Losses of volume occur due to breakage of the packaging and theft. Less volume is lost when wire-bound boxes and sealed cartons are used instead of other types of packaging.

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RF Insect infestation / Diseases

Blue mold rot or storage rot is the most feared storage disease of citrus fruits and is caused by two species of mold: green mold (Penicillium digitatum), which is of an olive-green color, and blue mold (Penicillium italicum), which is of a blue-green color. The fungal spores mainly penetrate through small injuries and initially form white, circular spots of fungal growth, which are subsequently covered from the center outwards with a green or blue-green sporulating layer. The peel becomes spongy, the pulp soft – a typical instance of wet rot. Development is optimal at 20 – 27°C; growth still flourishes at 10°C and comes to a standstill only at 4°C. Blue mold is transferred from fruit to fruit by contact.

Seawater, rain and condensation water promote green and blue mold growth.

Photo, blue mold

Figure 8 Photo, blue mold

Figure 9 Photo, blue mold

Figure 10 Photo, blue mold

Figure 11 Drawing, blue mold

Figure 12

Black rot (beginning at flower end) and stem-end rot (beginning at stem-end) are forms of dry rot which may occur as early as during harvest. Moisture promotes blue mold rot and black rot.

The Mediterranean fruit fly (Ceratitis capitata), a quarantine pest, in particular attacks thin-peeled citrus varieties, especially oranges and mandarins. The 8 mm long maggots of this boring fly in particular attack ripening and ripe fruit, causing rotting. Complete destruction of affected fruit and the use of contact insecticides during the flight time are the most effective methods of control. Countries apply strict quarantine measures to prevent introduction of this pest. Import of affected fruit is prohibited. Since these pests have many different food sources (being polyphagous), they can find food throughout the year in the Mediterranean region; in January mandarins are attacked, from February to May early to late oranges, in the summer peaches, apricots and pomaceous fruit and, at the beginning of winter, back to mandarins. Externally visible signs of attack are sunken, soft, black puncture marks and, subsequently, brownish discoloration of the peel.

The quarantine regulations of the country of destination must be complied with and a phytosanitary certificate may have to be enclosed with the shipping documents. Information may be obtained from the phytosanitary authorities of the countries concerned.

Orange packing methods:
Citrus fruit is hand picked in the field and brought to our facility in bins. When it is ready to be packed the bins are placed on our state of the art dump line. The the bins are submerged into water which allows the fruit to gently float out of the bins and onto the production lines. The fruit is then washed before being electronically graded by our Aweta-Autoline grader. It is then waxed to help preserve and protect it during its journey to stores around the world. After it has been dried it is carefully looked at by our well trained and experienced personnel in order to verify the citrus meets our high quality standards. It is then electronically sized by our Aweta-Autoline sizers and sent to various packaging stations. The majority of the fruit is then packed using automated packing and bagging systems, though some packaging and sizes still require packaging by hand. Once in its container the box is labeled by our ProduceJet system with key product and tracing information.

Oranges are presented in multiple packages. In the supermarkets we usually find them in bags or nets up to 3 kg or in boxes up to 15 kg for the consumer to select them. Expanded polystyrene trays of 6 units are also usual.

A big range of packages are used to pack oranges. The units of sale that we usually find in supermarkets, shops, etc., are boxes, bags or nets up to 3 kg of capacity.

When they are not prepackaged, the shop usually receives the oranges in packages of 7 up to 20kg.

We also find oranges in the fruit counters in boxes of 2, 2,5, 3, 10 and 15 kg, with the fruit arranged in an aesthetical way, in different layers for the free selection by the consumer. Many of these oranges are wrapped in paper, showing the label of the brand in order to call the client’s attention.

In some supermarkets we frequently find packages of 60 and 180 kg, great boxes whose base is a pallet with 1.5 or 2 kg nets.

In many shopping centers, in order to save space in the consumer’s pantries, oranges are displayed in expanded polystyrene trays of 6 units, covered with plastic film.

There are also trays with a mixture of oranges, apples and bananas to make the purchase easier for the consumer, since these are the fruits we buy more.

Packaging and storage of orange juice
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In this chapter you will read about:

The quality parameters that need protection during storage and what affects them. 

The role of oxygen in vitamin C degradation, juice browning and flavour changes.
The impact of light on juice quality.

Orange juice aroma and the effect of different package types on aroma retention.
Different packaging systems.

One of the primary aims of a packaging system is to protect the product from microbial spoilage and chemical deterioration during distribution and storage. For orange juice, measures should be taken to protect vitamin C and flavour compounds, and to prevent microbial growth and colour changes. 

Vitamin C is the compound in orange juice that reacts most readily with oxygen, and its loss correlates with the oxygen-barrier properties of the package. The degradation products of vitamin C contribute to browning. 

Light, in combination with excessive oxygen (head-space and dissolved oxygen, and high oxygen permeation through the package), is known to accelerate flavour changes and aerobic degradation of vitamin C. Anaerobic degradation of vitamin C also takes place but independent of oxygen. 

High storage temperatures combined with oxygen are the main factors involved in quality deterioration over time.

The results are loss of nutritional value concerning vitamin C, unpleasant colour changes, and off-flavour formation, which is caused predominantly by chemical changes in the juice matrix and, to a lesser degree, by changes in the volatile flavour fraction.

Almost all changes can occur under anaerobic storage conditions and are greatly accelerated by oxygen (headspace and dissolved oxygen, and oxygen permeating through the package).

In general, packaging for orange juice should contain an aroma barrier to prevent aromas permeating out through the package.

Laminated carton packages are the most common form of packaging in most countries for chilled and shelf-stable orange juice. They are either made from prefabricated blanks or fed from rolls. Worldwide, plastic bottles are the second most common type of container, followed by glass bottles.

One of the main aims of a packaging system and packages is to protect orange juice from microbial spoilage and chemical deterioration during distribution and storage. The shelf life of food and beverages is the time period up to the point when the product becomes unacceptable from a safety, sensorial or nutritional perspective. The influence of packaging material and package type on the shelf life of orange juice has been the subject of many investigations.

Although the package is important in protecting its contents, it cannot improve the quality of orange juice made from poor raw materials or disguise quality degradation originating from non-optimal processing. Moreover, it is inevitable that product deterioration related to product-specific characteristics and storage conditions gradually takes place over time. Therefore, regardless of the package, degradation of vitamin C and browning of orange juice always take place in stored orange juice when a certain temperature and/ or storage time is exceeded.

In conclusion, the quality of orange juice at consumption depends on all the processing and packaging steps from raw material intake up to the product being consumed. Some important operating parameters which influence juice quality at different steps are presented in Figure 9.1.

ZoomFigure 9.1
Factors which influence juice quality

In addition to its most obvious function of containing the product, a consumer package must protect the specific quality parameters of orange juice. To better understand the term “quality parameters”, one could question why consumers buy orange juice. The main answers will most probably be its enjoyable taste and high nutritional value due to a high vitamin C content. Therefore these quality parameters should be protected during a given shelf life.

This means taking measures to:

Protect the relevant flavour compounds 

Protect the high vitamin C content 

Prevent colour changes 

Prevent microbial growth 

No packaging system is able to completely prevent changes in quality taking place in orange juice – or other beverages in general – during storage. From the day of processing to the day of consumption, the product will change to a certain extent dependent on storage conditions. And in most cases, with the possible exception of wines, the changes will be for the worse.

With regard to the quality parameters already identified for orange juice, the packaging and storage conditions given in Table 9.1 influence how long an acceptable quality can be retained during storage.

Table 9.1 Factors influencing shelf life

Package properties Storage conditions
Barrier against • Oxygen
• Time • Temperature
• Light • Aseptic
• Flavour losses • Non-aseptic
• Microorganisms
Before looking more closely at package barrier properties, it is important to keep in mind that packaging can never be discussed without considering the intended storage conditions – particularly temperature and time – because these are the main determinants of barrier demands.

Oxygen plays a major role in the loss of quality in orange juice during storage, mainly because of:

Vitamin C degradation 

Colour changes (browning)

Several publications also indicate the negative impact of oxygen on flavour compounds and on off-flavour formation during the storage of orange juice at ambient temperature. This is, however, a contentious area that is a matter of some debate. 

Vitamin C is the most oxygen-sensitive compound in orange juice. Its loss is thus closely related to oxygen content in packages. Generally, vitamin C is lost through two different chemical pathways – anaerobic and aerobic degradation. As its name implies, the anaerobic pathway is independent of oxygen and dependent mainly on storage temperature. Losses caused by anaerobic degradation cannot be prevented by packaging and are the same in all types of package. The only possible counter-measure is to reduce storage temperature.

The aerobic pathway needs oxygen and is therefore strictly related to the presence of headspace oxygen and oxygen dissolved in the juice, as well as the oxygen-barrier properties of the package.

Both anaerobic and aerobic degradation take place simultaneously in orange juice. Which one dominates depends on storage temperature and oxygen availability.

For packages with good oxygen-barrier properties, for example glass bottles, anaerobic degradation plays the major role regarding total vitamin C loss. In cases where oxygen permeation into the package is considerable, headspace oxygen is present or oxygen is dissolved in the product, the contribution of anaerobic degradation to total vitamin C loss is small compared to aerobic degradation.

Examples of vitamin c loss for a 1-litre package during ambient storage based on stoichiometric calculation

Headspace A headspace volume of 5 ml air, containing 1 ml oxygen (about 21%), can theoretically oxidize approximately 15 mg vitamin C.

Dissolved oxygen 1 mg oxygen corresponds to a loss of approximately 11 mg vitamin C.

Anaerobic degradation
The anaerobic degradation corresponds to an approximate loss of:

1 mg/l vitamin C per month at 10°C

5 mg/l vitamin C per month at 20°C
20 mg/l vitamin C per month at 30°C

Oxygen permeating through the package
An oxygen permeability of 0.02 ml oxygen/ package/ day in a 1-litre package results in a loss of 9 mg/l vitamin C per month during ambient storage.
For a package with a permeability of 0.05 ml oxygen/ package/day the loss is 22 mg/l vitamin C per month.

Since both anaerobic and aerobic pathways for vitamin C degradation occur simultaneously in most packaged products, vitamin C degradation curves cannot usually be attributed to solely one pathway.

Figure 9.2 shows vitamin C degradation in orange juice stored at ambient temperature in two package types– laminated cartons with a barrier layer of aluminium (Al) foil in the first type and of a polymer, such as ethylene vinyl alcohol (EVOH), in the other. The Al-foil layer is a good oxygen barrier, whereas packages with a polymer barrier layer like EVOH allow higher oxygen permeability. Some packages were stored in an oxygen-free atmosphere, and in this case the vitamin C loss represents mainly the anaerobic degradation pathway.

ZoomFigure 9.2
Vitamin C degradation curves for different packages of orange juice stored at 23 °C.
Source: Tetra Pak

It is quite obvious that when oxygen permeability of a package exceeds a certain point, the aerobic pathway predominates. The anaerobic reaction pathway is mainly temperature-driven. The impact of temperature can be seen from the example of a 1-litre package in the fact box.

ZoomFigure 9.3
Effect of temperature on vitamin C content in orange juice during storage.
Source: Tetra Pak

Storage temperature is also important for aerobic degradation of vitamin C. Figure 9.3 shows the change in vitamin C content in orange juice during storage for 30 weeks at 4°C and 23°C respectively in the same package type (Tetra Brik Aseptic, TBA, 250 ml). The calculated vitamin C loss due to anaerobic degradation is indicated in the graph. The difference in vitamin C retention between storage at 4°C and 23°C is obvious. During 30 weeks storage, an increase in temperature from 4°C to 23°C results in increased losses of vitamin C of 28 mg/l due to anaerobic degradation, and 42 mg/l due to aerobic degradation.

The rate of oxidative degradation of vitamin C is slowed dramatically under chilled storage. Consequently, packages for chilled distribution do not need as high oxygen-barrier properties as packages stored at ambient temperature.

The colour of orange juice is primarily determined by its carotenoid content. However, carotenoids are relatively stable in orange juice since they are protected by vitamin C and are not regarded as being responsible for the colour changes that occur during long-term storage at ambient temperature

The colour changes, or rather the darkening, during storage are based on the appearance of brown-coloured compounds caused by the chemical reaction of orange juice components present in the juice matrix. The brown compounds are formed in the end phase of the so-called “Maillard Reaction” (also known as non-enzymatic browning), which is a well-known reaction between sugars and amino acids. This reaction type is generally not dependent on oxygen, but is clearly temperature-driven.

Figure 9.4 shows the effect of temperature on the browning of orange concentrate. It is evident that browning results mainly from long-term storage at temperatures higher than 12°C.

Vitamin C can participate in the development of browning through its degradation by-products generated both by aerobic and anaerobic pathways. Consequently, the oxygen barrier of a package influences browning because it determines the supply of oxygen to the aerobic pathway of vitamin C degradation.

Figure 9.5 shows colour changes in orange juice in packages with different oxygen-barrier properties during storage at 23°C. There is a clear increase in browning with increased oxygen permeation through the package. This allows the conclusion that the better the package oxygen barrier, the lower the risk of browning.

ZoomFigure 9.4
The browning of orange concentrate during storage at different temperatures.
Source: Values taken from Kanner et al.

ZoomFigure 9.5
Colour changes in orange juice in packages with different oxygen-barrier properties during storage at 23°C.
Source: Tetra Pak

Methods of measuring colour in orange juice are described in subsection 2.2.4.

The orange juice flavour is composed of a broad mixture of different aroma fractions, which contain a variety of volatile compounds as described in more detail in subsection 9.4. These aroma compounds may undergo several changes during storage that gradually lead to a loss of freshness and the formation of an unpleasant aroma (off-flavour). Most of these changes are acid-catalyzed reactions, which are supported by the acidity of the juice and accelerated by high storage temperatures.

Degradation pathways of important aroma fractions like aldehydes include oxidative reactions. Thus, it cannot be excluded that oxygen content and hence the oxygen-barrier properties of the packaging solution have an impact on the aroma of the packed orange juice. However, as vitamin C is a quantitatively important anti-oxidant in orange juice and immediately reacts with available oxygen, the impact of oxygen on the aroma is less pronounced as long as vitamin C is present.

Three compounds have been identified as important off-flavour contributors in orange juice, independent of the packaging used. These compounds, which gradually develop in juice, are:

4-vinyl guaiacol (PVG) 

2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF)

When these compounds are added to freshly prepared orange juice, PVG imparts an old fruit or rotten fruit aroma; DMHF imparts a pineapple-like aroma typically found in old orange juice and alpha-terpineol is described as stale, musty or piny.

The formation of PVG results from storage-induced changes in the juice matrix, DMHF results from the so-called Maillard reactions between carbohydrates and proteins, and á-terpineol is a degradation product of the aroma compound limonene. All three reactions are supported by the acidity of the juice and storage temperature. Since vitamin C’s oxidative degradation products can participate in the Maillard reactions, the package oxygen-barrier properties (and thus a more pronounced vitamin C decay) can to a certain extent also impact the sensory properties of orange juice, primarily colour (browning) and, to a lesser degree, flavour.

Figure 9.6 gives an overview of the flavour changes that occur in orange juice during storage.

ZoomFigure 9.6
Storage-dependent flavour changes in orange juice

Light is known to accelerate the aerobic (but not an-aerobic) degradation of vitamin C. One can therefore conclude that:

Light has an effect only when oxygen is present. Consequently, packages with high oxygen-barrier properties, such as glass and high-barrier PET bottles, do not need a light barrier. 

During storage at ambient temperature in packages with a good oxygen barrier, low oxygen permeation rates limit the rate of vitamin C degradation. Moreover, all oxygen entering through the package is almost immediately consumed. Thus, light cannot accelerate the reaction and therefore has no significant impact. 

During chilled storage, for which packages with higher oxygen permeability are mainly used and the reaction between vitamin C and oxygen is significantly slowed down, oxygen will accumulate in the product. Light can then accelerate vitamin C degradation.

As a result, light protection should be primarily considered for use in packages for chilled distribution that have low oxygen-barrier properties. 

The basic structure of aroma compounds 

A group of compounds that contain only hydrogen and carbon in their molecular structure. Example: d-limonene 

Alcohols, aldehydes and esters contain only hydrogen, oxygen and carbon in their molecular structure. 

Typical functional group: R-OH Example: linalool 

Typical functional group: R-CHO Example: hexanal 

Typical functional group: R-COOR Example: ethyl butyrate 

R = a particular molecular side chain
The concentration of an aroma compound cannot be correlated directly with its importance for flavour
In most cases, orange juice packaging is required to provide a barrier that prevents aroma compounds from permeating out through the package. Another requirement of packaging is to provide a barrier against odours from the surrounding atmosphere entering the packaged orange juice. This subsection discusses the composition of the aroma fraction in orange juice and the properties of different polymers and different packages commonly used.

Orange juice aroma, as a term generally used in this section on packaging, includes all the volatile compounds of orange juice flavour. Hence it is not identical to “essence aroma” (or water-phase aroma), which is the water-soluble volatile fraction recovered in the essence recovery unit during evaporation. See also section 2.2.

Orange juice aroma is a complex mixture of many volatile compounds. In chemical terms, it is mainly a mixture of hydrocarbons, aldehydes, alcohols and esters (see fact box). The predominant fraction consists of hydrocarbons, of which one single compound, d-limonene, accounts for more than 90% of the total aroma fraction. The aroma oil content of orange juice is usually evaluated by a standard test method (Scott titration), which more or less reflects d-limonene content only. Therefore, limonene loss during packaging and storage is often incorrectly equated to flavour loss.

It is not possible to correlate directly the relative concentration of an aroma compound with its importance for flavour. For example, a compound that is 90% w/w of the aroma fraction may contribute very little to the flavour, whereas a compound that has only a 0.001% w/w share of the aroma fraction may have a very high impact on the flavour sensation. The reason is that the human nose and taste buds can respond very differently to compounds of different chemical structure.

Besides specific knowledge about the composition of aromas, it is also essential to identify those individual aroma compounds that contribute most to taste and smell of the product.

Table 9.2 The contribution of volatiles to orange juice aroma
Contribution to typical aromas Contribution to off-aromas
Important Desirable Precursors Detrimental
ethyl butyrate linalool linalool α-terpineol
neral limonene limonene carvone
geranial α-pinene valencene t-carveol
valencene nootkatone
acetaldehyde hexanal
octanal t-2-hexenal
nonanal hexanol
α-sinensal 4-vinyl guaiacol
ß-sinensal 2,5-dimethyl-
3-(2H) furanone
Source: Dürr et al.
Dürr et al. (1981) categorized juice aroma compounds in four groups, listed in Table 9.2. The categories remain valid today:



Off-odour precursors
Off-odour precursors are compounds that can undergo chemical changes during storage leading to undesirable off-odours, even if the original compounds themselves may contribute positively to orange aroma. Limonene, linalool and valencene are examples of off-odour precursors.

Permeation through polymers
P = D× S
Permeation rate = Diffusion × Solubility
Aromas can be absorbed into or permeate through the packaging material depending on the type of aroma compound (chemical class, polarity) and the nature of the packaging material. This effect, often called “flavour scalping”, has been extensively studied, especially for laminated carton packages.

The absorption and/or permeation of aroma compounds through polymers is based on the general equation that permeation (P) is a product of diffusion (D) and solubility (S), P = D×S. Consequently, only those aroma compounds with high diffusion and solubility coefficients in respective polymers are likely to be lost through permeation or absorption during storage. The solubility of a compound in a polymer can be estimated simply by making use of the fact that “like dissolves like”.

In non-polar polymers, such as polyolefins, non-polar aroma compounds like limonene have high solubility. Low-density polyethylene (LDPE), high-density polyethylene (HDPE) and polypropylene (PP) are examples of polyolefins. While there is a minor difference in solubility for non-polar aroma compounds in the stated polyolefins, their diffusion and consequent permeation rates differ by orders of magnitude in the different polyolefins - in decreasing order LDPE>HDPE>PP. Aroma losses into the polymer layer are therefore significantly slower in PP and HDPE than in LDPE.

Unlike non-polar components, polar components such as ethyl butyrate have low solubility in polyolefins. As a result, their permeation rates are very low and losses due to permeation are negligible in barrier packages with LDPE as product-contact layer.

Polar polymers like polyester (PET), EVOH and polyamide (PA) basically show very low diffusion coefficients with polar and non-polar aroma compounds. This results in good barrier properties against both types. However, polar polymers are sometimes more difficult to heat-seal than polyolefins.

In summary, aroma losses due to absorption into or permeation through polymer packaging primarily involve non-polar aroma compounds (for example hydrocarbons like limonene) in contact with non-polar polymers (LDPE, HDPE, PP) commonly used as sealing layers. Polar polymers (PET, PA, EVOH) exhibit minimal absorption of aroma compounds and thus provide an effective aroma barrier.

The extent of loss of aroma compounds due to absorption or permeation can vary significantly between different package types. Generally speaking, three package types can be distinguished as shown in Figure 9.7:

Type 1 package has no efficient aroma barrier (for example carton packages without a barrier layer and monolayer HDPE bottles).
Type 2 package has an aroma barrier not in contact with product, and a sealing layer like LDPE in contact with product. Most laminated cartons are type 2 packages. Also HDPE bottles incorporating a barrier layer belong to this group.
Type 3 package has an aroma barrier in direct contact with product (for example glass and PET bottles).
Because absorption and permeation mainly involve non-polar aroma compounds, limonene is a key compound in monitoring flavour scalping. For the three package types, the loss of limonene can be demonstrated using the graphs shown in Figure 9.8. 

ZoomFigure 9.7
The three general types of package

ZoomFigure 9.8
The loss of limonene during storage in the three package types


Limonene content decreases continuously by permeation through the package due to the absence of an aroma barrier. The loss over time depends mainly on the choice of polyolefin polymers, and the slope of the curves is determined by the diffusion of limonene into the individual polymers. For a given shelf life, such as nine weeks, the limonene loss in PP would therefore be lower than in LDPE. 

Type 1 packages cannot be used for long-term storage of orange juice at ambient temperature because of the extensive loss of aroma compounds. Moreover, the absence of an aroma barrier also implies the lack of an oxygen barrier. (Oxygen barriers are generally also good aroma barriers.) It is possible to use Type 1 packages for orange juice stored chilled for a few 
weeks, as is done in the US market with monolayer HDPE bottles. The low diffusion coefficient of HDPE limits aroma loss within the short shelf-life period. When significant loss of quality needs to be prevented, laminated carton packages based on LDPE as sealing polymer need an aroma and oxygen barrier, even under chilled storage conditions.

In this package, which has an aroma barrier and a polyolefin sealing layer in contact with product, limonene content will decrease within the first few weeks of storage due to its absorption into the sealing layer. As soon as this layer is saturated with aroma compounds, an equilibrium level will be reached and no further absorption/permeation will take place because the effective barrier (such as Al-foil, PET, PA, EVOH) behind the sealing layer prevents further permeation through the material structure.

The extent of limonene retention at equilibrium is determined in this package type by the thickness of the internal sealing layer and by the ratio of internal surface area to product volume of the packages. The larger the package size and the lower the internal coating thickness, the higher the limonene retention. Saturation will be reached after 2-4 weeks at ambient temperature. HDPE bottles that comprise a middle layer of barrier material (such as EVOH) show similar patterns of aroma absorption.

Type 2 packages are used extensively for orange juice distributed at ambient temperature or under chilled conditions.

In this package, the aroma barrier is in direct contact with product and practically no limonene absorption or permeation takes place. The slight loss of limonene that occurs during storage at ambient temperature is related only to chemical degradation, which is independent of the packaging. Type 3 packages are mainly glass and PET bottles. In flexible packages, aroma-barrier polymers simultaneously used as sealing layers are sometimes more difficult to seal than polyolefins.

Laminated cartons used for orange juice packaging are often Type 2 packages, which allow a certain degree of flavour scalping.

However, absorption into this package type does not affect the whole aroma profile but rather the non-polar aroma compounds like limonene. Nevertheless, the barrier (Al-foil) in the laminate structure limits the loss of non-polar aroma compounds.

The question thus arises of whether flavour scalping has a significant impact on juice quality and taste. This subject is a matter of controversy in the literature. Dürr et al. (see Table 9.2) ranked the hydrocarbon fraction of orange juice aroma mainly under the desirable portion. However, they also indicated that limonene, for instance, is a precursor for development of off-odour during storage. They showed that losses of up to 40% of limonene actually had no effect on the sensory quality of orange juice during 90 days’ storage at 20°C, and suggested that limonene made a low contribution to the typical aroma of orange juice.

Joint investigations between Tetra Pak and the Citrus Research Centre in Florida (Pieper et al. 1992) showed that flavour scalping of up to 50% of the original concentration of limonene in orange juice has no effect on the sensory ranking in a preference hedonic scale test of quality of orange juice stored for up to 23 weeks at 4°C.

Although absorption of limonene into the inner layer of barrier packages was found not to affect the taste of the juice, additional aroma oil is sometimes added in juice preparation to compensate for any loss caused by limonene absorption, for example when the same product is distributed in several different package types.

Flavour scalping
The term flavour scalping is widely used in publications to mean the almost exclusive absorption of limonene into the internal polyethylene coatings of laminated carton packages.

As limonene contributes little to orange juice flavour, the loss of limonene does not correlate with the loss of flavour in a product.

For storage at ambient temperature, it is essential that:

Orange juice is free from spoilage microorganisms when packed 

Packages do not recontaminate the product 

Packages provide an effective barrier against 
external microorganisms 

Since these conditions are an absolute prerequisite for storage at ambient temperature, product shelf life is not determined by microbiological factors but by quality changes that are due to inevitable temperature-driven reactions and oxidative reactions. The latter are directly related to the package barrier properties. 

For juice under chilled distribution, the situation can be more complicated. Microbial spoilage may become the limiting factor of shelf life depending on the selected heat treatment of the product, hygienic status of the packaging system and storage temperature of filled packages (2-10°C). 

It is outside the scope of this section to discuss the different options with respect to expected shelf life under chilled conditions, but it is important to understand that the requirements for other barrier properties of a package depend on whether or not product shelf life is limited by microbiological spoilage. For example, if a juice is spoiled by microbial action after three weeks at 4°C, the aroma and oxygen barrier properties are of minor importance compared with a package where the juice is spoiled by microorganisms after six weeks or more. In this case, enhanced aroma and oxygen barrier package properties are required to meet the extended shelf life.

For aseptically packed juice, the oxygen and aroma barrier properties of the package determine product shelf life because there is no microbial action.

Figure 9.9 presents the factors that affect product shelf life and their relative importance during chilled and ambient distribution.

ZoomFigure 9.9
Factors affecting product shelf life and their relative importance during product distribution

Orange juice for home consumption is sold mainly in shelf-stable or chilled form. The shelf-stable form, stored at ambient temperature, dominates all global retail markets except in the US, where chilled juice leads. Frozen concentrate for home dilution was popular in the US but has declined to a minor product. It is rare elsewhere because of poor quality domestic water or the inconvenience of dilution.

Ready-to-drink juice from concentrate and NFC sold as shelf-stable products are pasteurized and either packaged aseptically or hot filled. The types of orange juice sold in chilled form – freshly squeezed juice, NFC and ready-to-drink juice from concentrate – are not usually packaged aseptically or hot filled.

Laminated carton packages are the predominant form of orange juice packaging in most countries. Worldwide plastic bottles are the second most common type of container, while glass bottles today play a minor role in orange juice packaging. Nevertheless, in some markets like France and Germany certain consumer groups still favour glass bottles. Today, less and less juice for consumption is sold in cans, although Japan is one exception. PET, usually with an added oxygen barrier, is the most common material used for plastic bottles containing ambient orange juice. In bottles for chilled juice a shift is under way from HDPE to PET.

The packaging preferences for fruit juices (all flavours) in Europe can be seen in Figure 9.10.

ZoomFigure 9.10
Packaging of fruit juice in Europe.
Source: Tetra Pak

The laminated carton material normally consists of layers of paperboard coated internally and externally with polyethylene, and a barrier layer.

The most commonly used barrier layer today is Al-foil. Other barriers include ethylene vinyl alcohol (EVOH) and polyamide (PA). A schematic structure of laminated packaging material for orange juice cartons is shown in Figure 9.11. Depending on the packaging system used, the packaging material is delivered to the juice packer as prefabricated carton blanks or printed and creased in rolls.

ZoomFigure 9.11
The structure of a laminated packaging material

Oxygen-barrier properties of a laminated carton package depend not only on the barrier properties of the packaging material itself, but also on the barrier properties of strips and closures and the tightness of seals.

With prefabricated systems, the blanks are die-cut and creased, and the longitudinal seal is completed at the packaging material factory. The printed flat blanks are delivered to the juice packing facility, where they are finally shaped and sealed in the filler.

Blanks to be used for chilled orange juice are handled under non-sterile conditions but steps are taken to avoid recontamination of microorganisms. The filling temperature should be low (4-5°C or less) to minimize microbial growth. At these low temperatures the risk of foaming is higher compared with filling at higher temperature.

Some packages made from prefabricated blanks are shown in Figure 9.12.

ZoomFigure 9.12
Carton-based packages made from prefabricated blanks

Packaging materials are supplied in rolls that have been printed and creased. The packaging material roll is fed into a machine, where it is formed into a tube and the longitudinal seal made by a heat-sealing system. In this process, a strip is heat-sealed along the inner surface of the longitudinal seal (LS) to protect the different layers of packaging material from contact with product and vice versa. The oxygen-barrier properties of the longitudinal seal are important for oxygen-sensitive products such as orange juice.

Juice is poured into the tube and a transversal seal (TS) is made below the level of the orange juice. This results in headspace-free packages. Alternatively, packages may be produced with a headspace either through nitrogen injection or low-level filling. Packaging without headspace or with an oxygen-free headspace is advantageous for orange juice and other oxygen-sensitive products because it eliminates a significant source of oxygen and associated quality changes.

Carton-based packages with a polyethylene top are made from roll-fed packaging material as well. In the filling machine the material is cut into sheets, which are folded and longitudinally sealed. The plastic tops are injection-moulded and sealed with the sleeve to form a package. After filling from the bottom, the bottoms are sealed by heating elements.

Figure 9.13 shows various carton-based packages - with and without headspace - made from rolls.

ZoomFigure 9.13
Carton-based packages made from rolls

In an aseptic filling system, the material web is sterilized with hydrogen peroxide (H2O2) or by electron beam. Hydrogen peroxide is used either in a wetting system or a deep bath system, after which the H2O2 is completely evaporated.

In electron beam sterilization, the packaging material passes in front of an e-beam lamp that emits a jet of high-energy electrons that kill microorganisms on the material surface. Less energy is used for e-beam sterilization as heating and drying of H2O2 is not required.

The subsequent filling and sealing processes are all performed inside a sterile chamber under positive pressure.

Glass bottles still play an important role in several markets worldwide. For shelf-stable orange juice in glass bottles, the most common filling method is hot filling. Aseptic filling of glass bottles at ambient temperature is of minor importance compared to hot filling. Of the package types used today for orange juice, glass bottles are normally considered to have the best oxygen barrier properties.

In hot filling, the deaerated and heated juice is directly poured into cleaned bottles that are capped. The filling temperature is usually between 90°C and 98°C. Preheating of glass bottles is necessary to reduce the

risk of glass splintering at filling. The required holding time for capped hot bottles, prior to cooling in a tunnel, depends on the level of microbial contamination of the empty bottles.

The hot product sterilizes the inside surface of the bottle, whereas bottle closures should be sterilized before they are applied to the bottle. Prior to closure, the bottle neck is flushed with steam. Steam injection keeps foaming to a minimum and reduces the oxygen content of the neck space as well as the recontamination risk. Hot filled bottles are frequently overfilled in order to ensure sterilization of the neck by the hot product. Other possibilities for neck sterilization are to tilt the bottle or turn it upside down.

ZoomFigure 9.14
Glass Bottles

Blow-moulded plastic bottles are today the dominant bottle type for orange juice, far exceeding the use of glass bottles. The most common plastic bottles are polyethylene terephtalate (PET) followed by high-density polyethylene (HDPE).

ZoomFigure 9.15
Plastic bottles

As HDPE has a poor oxygen barrier, plain HDPE bottles allow relatively high oxygen ingress and are used for chilled juice of short shelf life only (about three weeks). The oxygen barrier can be improved by adding intermediate layers of polymers with superior barrier properties. The most common barrier layers in HDPE bottles for orange juice are ethylene vinyl alcohol (EVOH) and polyamide (PA). These also provide an aroma barrier and can allow ambient storage for six months or longer, depending on the choice and thickness of the barrier layer.

HDPE bottles are fairly opaque, often pigmented, and produced by the extrusion blow-moulding (EBM) process. Contrary to PET, HDPE bottles exhibit high thermal resistance and can be hot filled as well as sterilized in autoclaves. With the increased use of aseptic filling, however, ambient orange juice has shifted from HDPE to transparent PET bottles.

In extrusion blow moulding (EBM), the HDPE resin is first melted in a hot screw and pushed through a steel disk (a die) to form a hollow pipe of polymer known as a parison. When the parison is sufficiently long, the two halves of the bottle mould close around it. Then pressurized air blows into the parison so it takes the shape of the mould, thus the bottle is formed. The bottle is blown with a sealed dome that must be cut off before filling.

A barrier layer may be incorporated by co-extruding barrier material with HDPE in the parison. Barrier bottles typically comprise six or seven layers, including intermediate tie-layers and regrind material.

Bottles with an integrated handle can be made using the EBM process. EBM can also be used to produce PET bottles provided special grades of modified PET resin are employed.

PET bottles were introduced in the late 1970s for carbonated beverages. Their use has grown steadily in most beverage applications. Today, they are the most common container for still and carbonated drinks. Orange juice packaged in PET bottles is found in both the chilled and ambient segments; ambient juice is either filled aseptically or hot filled.

PET bottles are made by stretch blow moulding (SBM), starting with a preform. A preform is an injection-moulded PET tube closed at one end and with the finished neck at the open end. During blowing with high-pressure air, the heated preform is stretched both axially (using a stretch rod) and radially into the bottle mould (see Figure 9.16). The bi-oriented material gives the bottle high tensile strength and an increased gas barrier, which allows for lightweight bottles.

ZoomFigure 9.16
Stretch blow moulding of PET bottles
Source: Sidel

Stretch blow moulding equipment is available for all capacities: from small units for 6,000 bottles per hour to mega-systems producing 100,000 bottles per hour. There are also systems with integrated preform injection and bottle blowing (ISBM), starting with PET resin in-feed and a blown bottle out the other end.

In their natural state, PET bottles are transparent and colourless. However it is possible to produce coloured bottles by adding appropriate pigments to the raw PET material.

The robustness of PET bottles compared to glass is obvious, but they do not provide as good an oxygen barrier as glass. Standard PET bottles give a shelf life for orange juice of about three to four months; large volume bottles give a longer period. The inclusion of active (oxygen scavengers) and passive barriers in PET bottles may extend shelf life up to 12 months and more.

There are three main technologies for increasing PET bottle oxygen barrier properties. All three are applied to orange juice packaging:

Monolayer barrier preform, where the PET polymer is mixed with an additive compound (such as oxygen scavenger) during preform production 

Multilayer preform, with three co-injected layers: PET/barrier material/PET. The barrier material is an oxygen scavenger mixed with PET. Polyamide (PA) is mainly used for CO2 gas retention, and can also be added to the oxygen scavenger. 

Bottle coating, using plasma technology to coat the inside of the bottle with a barrier layer.
This technology requires an additional machine between bottle blowing and filling.

In many markets, PET bottles are collected and recycled into resin for use in new PET bottles. Compounds added during PET bottle production, including barrier additives, may reduce the quality of recycled PET material. 

Amorphous (non-crystalline) PET becomes “rubbery” at temperatures above 70-80°C. Hence, regular PET bottles are not suitable for hot filling of orange juice, which is normally carried out at 84-88°C. To withstand these high fill temperatures, the bottles’ heat resistance is increased by applying special conditions during stretch blow moulding. Such “heatset” bottles are blown in a hot mould to achieve higher crystallinity and minimized stress in the PET material.

When the hot product cools down after filling, a vacuum forms inside the capped bottle because the volume of the liquid decreases and headspace gases are absorbed into the juice. PET bottles for hot filling are therefore designed with “vacuum panels” (flat surfaces on the side of the bottle) or other features that absorb the volume variations between hot and cold conditions.

PET bottles for aseptic filling do not require heat setting as filling takes place at room temperature. They are usually of lower weight than hot fill bottles and allow more freedom in their design as vacuum panels or similar features are not needed. As a result, bottle costs are lower but aseptic filling is more complex and entails a higher capital investment.

Ambient orange juice in plastic bottles may be filled aseptically or hot filled. In the US, hot filling is the dominant practice for shelf-stable still beverages, as for orange juice. At European juice packers, however, aseptic filling prevails for orange juice in cartons as well as plastic bottles. In Asia, both systems are employed.

Hot filling for the production of shelf-stable orange juice involves pouring the heat-treated juice, without significant cooling, directly into the package. The high temperature of the juice is used to kill microorganisms on the package surfaces. The time period and temperature needed will depend on:

Microbial contamination of packages and closures 

Number of microorganisms in the surrounding air, production area and filling machine 

Quality requirements for the product 

pH value of the product 

Shape of the package 

Material used for packaging 

Glass bottles have to be heated before filling and cooled after filling by means of a cascade system; otherwise the glass will break. PET bottles have the advantage of tolerating immediate exposure to high filling temperatures and cooling rapidly after the hold time needed to kill spoilage microorganisms.

Aseptic filling technologies for orange juice in plastic bottles demand a considerably more complex installation than basic hot filling. Prior to filling with product, the PET (or HDPE) bottles are sterilized using a sterilant such as peroxyacetic acid (PAA) or hydrogen peroxide (H2O2). Bottles treated with PAA solution are then rinsed with sterile water, while bottles sterilized with H2O2 are dried with sterile air or nitrogen.

Several recent aseptic installations feature the sterilization of PET preforms instead of the blown bottles. The advantages of this approach include lower sterilant usage (H2O2 vapour) and possibilities to further decrease bottle weight. However, sterile conditions must be guaranteed during bottle blowing and transfer to the filling carousel. It results in a compact installation as SBM and filler are directly connected in a single block.

Figure 9.17 shows the heat treatment to which orange juice is subjected during aseptic filling and hot filling. For aseptic filling, the pasteurized juice is quickly cooled to filling temperature, whereas the time required to cool hot filled juice to ambient storage temperature is considerably longer. The cooling time depends on the bottle size and type of tunnel cooler.

ZoomFigure 9.17
Comparison of aseptic filling and hot-filling methods.
Source: Tetra Pak

To facilitate selection of the most appropriate packaging system for a particular juice, certain questions need to be answered. Some are listed below:

Which quality parameters should the packages protect and to what extent? One answer is the minimum vitamin C content at the end of product shelf life. 

How long is the expected product shelf life and at what storage temperature? 

How many of the parameters limiting product shelf life are left after processing? 

Is dissolved oxygen present in the orange juice and to what extent? 

Which oxygen barrier is needed to protect the selected quality parameters during the intended shelf life? 

Is a light barrier needed? 

Whatever packaging system is selected, the ultimate aim must be to maintain the quality of a particular orange juice product during its defined shelf life conditions. 

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This is possible when customers trust Unisorting to be their only supplier for every system requirement.

Farmsoft fresh produce app  delivers fresh produce packing, for cherry, berry, onion packing, pepper & capsicum packing, avocado, potato packing, broccoli, salad, spinach, loose leaf lettuce, cucumber, tomato packing, citrus, garlic, asparagus, onion inventory storage, potato inventory storage, carrot, bean, mango, seafood packing.   
The app also manages fresh cut flower, food service, coleslaw & slaw packing, banana, orange, lemon, lime, grape, seed, stone-fruit, cauliflower, strawberry, fresh produce ERP, flower packing
Fresh produce quality control is made easy with Farmsoft:  Farm management appMeat packing app for beef poultry seafood.

Fresh produce traceability app by Farmsoft provides potato traceability, onion traceability, tomato, fresh produce blockchain traceability, pepper & capsicum traceability, carrot, salad, leafy green, citrus, cucumber, asparagus traceability, seafood traceability app, fresh cut traceability, food service traceability app, coleslaw traceability, strawberry, banana, grape, seed, flower, loose leaf, QC, fresh produce barcode.  
Fully integrated traceability software manages meat traceability app for slaughterhouses, low cost meat packing, meat packing software, meat packing quality control, meat packing hardware requirements, slaughterhouse software, beef packing software solutions.

Additional traceability for farm to fork traceability, fresh produce profit analysis, chili processing, fresh produce production planning, fresh produce RFID, blockchain fresh produce, fresh produce supply chain planning, fresh produce sales solution, packhouse management software, fresh produce traceability app, fruit vegetable inventory management for fresh produce stock control fruit packing system for packhouse processing of onion storage and quality.  

Walmart food safety compliance app for date plantation software, SENASA, fresh produce RFID app, perishable inventory management software, fresh produce API integration, coleslaw production, XERO for fresh produce packers, inventory management app for fresh produce waste reduction.
Woolworths fresh produce compliance and Woolworths food handling compliance, Coles compliance, Coles labels, fresh cut packing storage traceability, post harvest traceability software, potato packing system, simple traceability solution, save time efficient inventory.

Reduce errors in fresh produce packing and processing, increase accuracy of fresh produce shipping, reduce administration costs fresh produce packing, less fresh produce waste, avocado software, potato solution, carrot solution, broccoli control, mango processing quality, apple packing and processing, pepper packing app by farmsoft, chili packing app, chili powder app, hot pepper sauce manufacturing.

Farmsoft vertical farming app, farm traceability app, farm budgeting, farm quality, farm inventory, farm diary, farm land management.

Download Farmsoft Brochures:   Fresh produce app    |    Meat packing app    |    Farming app    |     Fresh produce RFID   
Implement Farmsoft fresh produce apps to increase fresh produce business productivity in fruit & vegetable packhouse: reduce fresh produce waste, food safety compliance, for easy traceability, automatic inventory control, simple quality control, rapid recall and mock recalls, and 100% accurate shipping, meat packing app, optional farming app.

Farmsoft QC Quality Inspection app makes fresh produce quality control rapid and accurate for all fresh produce packers:  cherry, berry, onion, pepper & capsicum, avocado, potato quality, broccoli, salad quality inspection, spinach, lettuce, cucumber, tomato quality, citrus, asparagus, garlic quality inspection app, carrot quality, bean, mango, leafy greens, fresh cut quality inspection, food service quality app, coleslaw quality, strawberry quality inspection app, grape quality, meat quality control app, flower quality.