From farm gate to food plate

By Tarina Coetzee
The cold chain extends the shelf life of perishables, reduces food loss and waste, maintains product quality and improves food safety by suppressing the growth of potentially harmful bacteria.

In South Africa, 10 million tonnes of food go to waste every year. That is a third of the 31 million tonnes that we produce annually. According to the WWF, fruit, vegetables and cereals account for 70% of the wastage throughout the food-supply chain. The Council for Scientific and Industrial Research has valued this loss at R61.5-billion. Globally, between 30% and 40% of all food is wasted. Often the waste in less developed countries is due to a lack of infrastructure and knowledge to keep food fresh.

“Perishable products, such as fruit, vegetables, meat, fish, shellfish, dairy and flowers require refrigeration to substantially reduce the rate at which food deteriorates. Effective temperature management slows down the growth of microorganisms and the natural metabolic process. The effects of this is the slowing down of the product decaying, thereby increasing the shelf life. Continuous temperature management without disruptions helps reducing food loss and food waste,” says Vijan Chetty, general operations manager: coastal of the Perishable Produce Export Control Board (PPECB).

“Products must be placed under cooling as soon as possible with no interruptions in cooling. All equipment, handling and storage facilities and modes of transport must comply with good management practices. They must also be in sound working condition to ensure that the condition of the perishable products is maintained. Disruptions in cooling must be mitigated as much as possible. Gensets can be used on refrigerated containers to mitigate temperature fluctuations. Within the airfreight industry, thermal blankets and refrigerated containers can also be used to avoid fluctuations in temperatures. Temperature fluctuations normally occur during the stuffing, loading, off-loading and transhipment processes. These movements must be carried out seamlessly without temperature fluctuations,” he says.

Refrigeration of perishable products at the appropriate temperature and relative humidity percentage (RH) should start as soon as possible after harvest and be maintained during the entire cold supply chain (processing and packing, storage, transport and while on display in the supermarket). Ideally, the consumer will extend the cold chain while travelling home and again store properly upon arrival. All of this will slow the ripening process and thereby extend the shelf-life (the period from harvest to consumption) of the product tremendously.

“Managing temperature is of utmost importance when importing agri-food. The efficiency of the cold chain is subject to understanding the biological and chemical processes associated with perishability and using the best possible technologies in a well-planned manner to ensure that product is moved through the supply chain at the correct temperature.

“The use of sensors has been very important in managing temperature control and ensuring food quality. In addition to maintaining quality, specialised refrigeration is also critical when used as a post-harvest phytosanitary measure against potential pests’ infestation, such as cold sterilisation against fruit flies,” says Marianna Theyse, general manager of the Fresh Produce Importers Association (FPIA). “Products that ‘go off’ before reaching the port of entry in South Africa will be rejected by regulatory inspectors. This means that the consignment will not be allowed entry and will have to be returned to country of origin or destroyed, at the cost of the importer or exporter.”

In most cases the result of products experiencing temperature abuse is that the quality of the product is impacted. The shelf life will be shorter or the consistency or feel of the product will change. Think of ice cream as an example of something that is not really appealing once melted. It is even worse when frozen again. There are cases where the food can be harmful for a human to eat as food-borne illness develop in warmer temperatures. As far as what happens to the actual product, that depends on what the product is, what its condition is and where it happens. Is the issue that product does not meet customer requirements, but is still consumable? The effort around the globe is the attempt to rescue that food to a food bank, for example. If the product is not fit for human consumption, it might be used or reworked as animal feed, but most likely most of such product is destroyed or dumped in a landfill.

“Fresh fruit and vegetables are inspected upon arrival in South Africa by plant health inspectors to ensure that the product complies with the relevant plant health import conditions, including cold-chain integrity for special phytosanitary treatments such as cold sterilisation to protect produce from pathogen or insect infestation. Imported produce is also subject to South African food quality and safety standards,” she says.
Effective temperature management slows down the growth of microorganisms and the natural metabolic process.

“In short, the cold chain extends shelf life, reduces food loss and waste, maintains product quality and improves food safety by suppressing the growth of potentially harmful bacteria,” says Lizelle van der Berg, director of the Global Cold Chain Alliance (GCCA) South Africa.

“A great deal of research has been conducted over the years to establish what is the optimal temperature and storage conditions for nearly all products. The GCCA has excellent resources for its members that contains information on over 400 different commodities,” says Van der Berg.

“The use of best practices for storage and handling is the first step to ensure that products are kept on temperature. It can be as simple as knowing what the temperature/RH should be set at and maintain that. Of course, it is much more complicated than that once product starts to move in the cold supply chain.

“Technology can be great tool to help maintain proper temperature/RH. We find that making an educated decision about what is the best product suited for a member’s business need is key to growing a business in the cold chain. Selecting the most effective technology combined with updating employees on best practices is a recipe for success in maintaining the cold chain, regardless of what country you are in,” Van der Berg says.
The best bet for reducing fluctuation in the cold chain is to have each link understand their role and use the best practices for maintaining the cold chain, Van der Berg says.

“Although technology is important, it has been shown time and time again that human error is typically what leads to temperature abuse: leaving doors open in a facility or truck, not storing products in the proper temperature zone to begin with, storing hot product with cold, and leaving product sitting outside of a refrigerated space for too long by getting distracted by another task,” she says.

Jan Lievens, senior consultant on applied postharvest technologies, UTE South Africa, agrees that the human factor is extremely important in maintaining the integrity of the cold chain.

“Of course, refrigeration plays an important role in the process, but all too often the damage is caused by a lack of attention during the postharvest process. Both the farmer and importer or exporter have a responsibility to do it right every time. All the buyer is looking for, or rather should be looking for, is a quality product,” he says.

“The time of harvest, the process and timing until the produce gets under precooling, the humidity, the removal of airborne and ethylene control, the packhouse circumstances, the final correct packaging and cooling, the correct overall cooling, the correct transport, the capacity to store the cooled goods at the point of shipping, delays in the process and correct temperature controls in the containers are all critical points where attention to detail needs to be exercised.

Here is an example of how the cold chain should flow for temperature management:

  • Products are cooled down to the optimum temperature as soon as possible after production and then monitored during handling, storage and transport.
  • In both storage areas and vehicles there must be sufficient airflow and circulation of air to ensure that the cold air coming off the coolers is distributed right through the area to ensure consistent temperature all over, prevent ‘hot spots’ and remove any warm air from the chamber or area.
  • Packaging plays a role to maintain the temperature of the products for as long as possible while the product is not under cooling, and similarly the type of vehicle plays a role – the vehicle should always be fully enclosed and preferably insulated. If it is transported for a period exceeding a specified time, say one hour, the vehicle should also be refrigerated, in other words, the produce is transported at the optimum temperature.
  • Handling areas should also be cooled down to assist in the process, depending on the type of product.
  • Product should be loaded at properly enclosed docking bays with seals that prevent airflow from the outside of the building into the handling area.
  • Temperatures are monitored and recorded along The Cold Chain – this is either done manually or through the use of electronic temperature loggers that are either placed in the packaging (and connected with the item) or in the handling area, the storage area and the load area of the vehicle transporting the goods. Recording from the loggers are downloaded at the end of a trip and or monitored with alarms in place to determine that no uncontrolled fluctuations occur along the way or over time.
  • Properly managed processing areas and storage areas for perishables being exported from South Africa are registered by the Perishable Produce Export Certification Agency (PPECB) and regularly audited.

“You can grow the best possible product, which most of our farmers do, but that is only 95% of the job done. The other 5% generate 99% of your income,” he says.

In South Africa, the PPECB audits facilities of all exporters of perishable products to ensure compliance. Similarly, the National Regulator for Compulsory Specifications (NRCS) and the Department of Agriculture, Forestry and Fisheries (DAFF) audits exporters of fish and meat products respectively.

Perishable products for both imports and exports are transported by refrigerated modes of transportation. There have been vast improvements on the technical capabilities of refrigerated containers. Remote Control Monitoring (RCM) has been introduced by some of the shipping lines thus enabling clients to have real time temperature monitoring therefore assisting to mitigate risk. Most importers and exporters continue to use temperature data loggers. These temperature data loggers are retrieved and downloaded once the product arrives at its destination. This type of data loggers is rather reactive than proactive monitoring. Technological advancements in data loggers now make it possible to have near real time information. This is extremely beneficial to clients that proactively monitor the temperatures of their products. Refrigerated trucks are also capable of transmitting the information on temperatures to their clients.

Products must be placed under cooling as soon as possible with no interruptions in cooling. All equipment, handling and storage facilities and modes of transport must comply with good management practices. They must also be in sound working condition to ensure maintenance of the condition of the perishable product. Disruptions in cooling must be mitigated. Gensets can be used on refrigerated containers to mitigate temperature fluctuations. Within the airfreight industry thermal blankets and refrigerated containers can also be utilised to avoid fluctuations in temperatures. Temperature fluctuations normally occur during the stuffing, loading, off-loading and transhipment processes. These movements must be done seamlessly without temperature fluctuations.

The extent of the wastage is evaluated when poor quality perishable products arrive within importing countries. If the product can be salvaged, then sound quality products are repacked for the market or for processing purposes and the balance of the product is dumped. The entire consignment is dumped if it is totally in a state of poor quality. The deterioration of the product must be evaluated to determine the root cause and preventative measures should be implemented to avoid further losses.

Importing countries have their own unique requirements for packaging, labelling and packing. These requirements must be adhered to should importers and exporters wish to conduct business within these markets. South Africa exports some of their products to destinations with extremely stringent labelling and packing requirements. Some of these labelling requirements are printed in the language of the importing country. These labelling standards must be adhered to because they form part of the bi-lateral agreements between the importing and exporting countries.

Foreign markets dictate their importing requirements. South Africa is required to align its processes to ensure compliance should they intend to participate in these export programmes. The compliance to stringent importing quality, phytosanitary and food safety requirements is highly costly for the South African agricultural industry, says Vijan Chetty, general manager: coastal of the PPECB.

All countries have regulations relating to their import requirements. Quality, phytosanitary, food safety and labelling requirements are some of the importing requirements. All documentation and duties must be submitted to the relevant authorities (SARS). The applicable permits must be submitted to the authorities and the relevant inspections conducted.

There are different modes of transport available to import and export perishable products. They are air freight, sea (containers and specialised refrigerated vessels), road (refrigerated trucks) and rail. The choice is highly dependent on logistical arrangements, infrastructure and efficiencies. Cost is not always the determining factor when choosing a suitable mode of transport. Although air freight in general is more costly than sea freight, importers and exporters opt to use airfreight for products with short shelf life. All modes of transport for perishable products have their advantages and disadvantages.

Importers and exporters must be aware of the local regulations regarding imports and exports. The local authorities are best in guiding importers and exporters of these requirements. Within South Africa the Perishable Products Export Control Board (PPECB) advises the industry of the export requirements of perishable products.

Technological advancement is impacting refrigeration. New technologies and equipment are being developed to improve effectiveness and efficiencies. Modern refrigeration units can cool products from ambient to optimum temperature in a shorter period. Real-time information, traceability, effective monitoring, reduced cost and emissions has been introduced into these technological advancements.

Most of the packaging and labelling requirements are contained in legislation. In addition to the requirements in plant health, food safety and quality legislation, food may be required by private standards of retailers to have additional labelling, for example organic certification.

Distance (trade cost) and refrigeration plays an important role in choosing transportation mode. Fruit and vegetables are shipped via sea by means of container-liner shipping or conventional shipping. On a global basis, it is expected that the use of containers will continue to increase. Alternatively, reefer vessels can be used.

Note that the industry uses the informal word ‘reefer’ to denote refrigerated. Confusion arises when, for example, the phrases ‘reefer container’ and ‘reefer vessel’ are used. This is because the former refers to the container shipping industry while the latter refers to the conventional shipping industry – yet both have the word reefer in them. Reefer vessel means conventional vessel, whilst reefer container is a refrigerated container.

Alternatively, produce may be imported in containers via airfreight and this is usually done for high-margin produce such as berries where transit time is shorter. It may also be imported by road (trucks) in sealed containers (for example, bananas from Mozambique).

As with most developing countries, the availability of fresh produce in South Africa on a year-round basis has become the norm. Consumers want grapes when they want it and want to squeeze orange juice from fresh oranges whenever they feel like it and not necessarily when the fruit is in season.

South Africa is no exception and imports of out-of-season fresh produce have grown tremendously over the past 10 years. For this reason, the FPIA was established to facilitate and develop the fresh-produce import sector in South Africa. The FPIA acts as a platform through which importers can interact with each other, government and international agencies involved in the management and control of the perishable industry to achieve and facilitate free and safe trade of fresh produce into South Africa.

As an industry organisation, FPIA focuses on providing its members with the most recent and up-to-date regulatory information relevant to existing import markets to allow for effective supply-chain management in terms of such requirements. It engages with the relevant regulatory authorities as well as industry organisations in trade-partner countries to ensure that its members have access to verified information and stay informed about potential threats (especially SPS issues) to existing supply chains.

FPIA partners with various role-players along the supply chain to communicate and address specific challenges to import markets that are priority for its members, for example partnering with research institutions to conduct pest specific surveys that would address specific challenges to existing or potential new markets. Most importantly, it has partnered with some of the SPS regulatory authorities in South Africa to collaborate on or provide technical capacity assistance to improve compliance of the sector to SPS requirements. In cases of non-compliance, efficient handling of intercepted consignments is crucial because of the bio-security risk involved whilst detained at ports of entry or approved facilities as well as the potential financial losses to the importer due to quality deterioration and storage costs. An effective interception system is required that includes appropriate inspection and sampling, efficient diagnostic services, timely risk decision-making and subsequent phytosanitary management activities. Record-keeping and communication are essential to inform suspension of imports and prevent recurrence of the problem. FPIA aims to continue and improve on this partnership that will build and develop SPS capacity to ensure safe but free trade.

An important focus area for FPIA in terms of further capacity building is SPS related research in areas such as host specificity studies, biological control, pre and post-harvest technologies, post-harvest quality management and food safety in imports. Furthermore, FPIA is actively involved in the prioritisation and development of new import markets for South Africa. It regularly partners with the relevant regulatory authorities, technical experts, importers and potential partners in the exporting country to support the technical processes involved with market access for perishable products. It provides a forum for information exchange and therefore improves predictability of trade whilst lowing risk of interceptions.

Did you know?
Phytosanitary irradiation is a treatment that uses ionising radiation on commodities such as fruits and vegetables to inactivate pests such as insects. This method is used for international food trade to prevent spread of non-native organisms.


Modified Atmosphere Packaging: the freshest technology out there

By Gary Ward, technical development manager of StePac Israel, part of Johnson Matthey PLC UK

Modified Atmosphere Packaging (MAP) is a proven, high-performance fresh produce packaging technology designed to preserve freshness and good appearance, inhibit decay, extend storage and shelf life, and ultimately reduce waste within the supply chain.

Fresh fruits and vegetables continue respiring (breathing) after harvest. During the respiration process, the fresh fruits and vegetables consume oxygen (O2) in order to derive energy for driving cellular processes and emit carbon dioxide (CO2), heat, and water vapor. Storage life of fresh fruits and vegetables is inversely correlated with respiration rates – the higher the respiration, the more perishable the produce and vice versa. This is the underlying reason why produce with high respiration rates, such as broccoli, asparagus, mushrooms, spinach and sweet corn, have a much shorter shelf life than those with low respiration rates such as nuts, dates, apples, citrus, grapes, onions and potatoes.

Lowering temperature reduces respiration rate and extends storage, but is also well known that a reduction in O2 and an increase in CO2 concentrations and the generation of a so-called modified atmosphere, slows respiration rates of many fresh produce items and inhibits the biosynthesis and action of the plant hormone ethylene, responsible for the ageing and ripening processes. If the produce tolerates high CO2 concentrations a fungi-static effect can also be achieved, inhibiting fungal growth.
Successful implementation and sustained success of MAP is highly dependent on numerous factors:

  • Choosing produce varieties that respond well to MAP. Good cultivation and harvest practices that lead to the highest possible quality and storability.
  • Sorting and grading of the highest quality produce to pack.
  • Prompt cooling to the optimal storage temperature. It is critical to use the most suitable cooling technique for the produce in question, with the aim of cooling the produce as quickly as possible and minimising weight loss.
  • Good temperature management throughout the supply chain, including ongoing monitoring and mapping of temperature, can optimise the cold chain.
  • Proper disease management during cultivation and post-harvest. If produce is washed after harvest, then it should be in disinfected water to prevent cross-contamination and thoroughly dried afterwards. Approved fungicides are often recommended in order to supplement the packaging in reducing the risk of microbial decay.
  • Advanced packaging – designed to provide optimal modified atmosphere and yet tolerant to temperature fluctuations; inevitable in most supply chains.
  • Condensation control of well-designed MAP – also manages the humidity inside the packaging. As produce respires, relative humidity inside the packaging increases, and at equilibrium, will be close to saturation. Condensed water on the surface of fruits and vegetables can adversely affect the gas exchange of the produce, leading to an unfavourable internal atmosphere. The most noticeable effect of condensation is accelerated microbial growth and subsequent decay. Selection of a film with a suitable Water Vapor Transmission Rate (WVTR) that takes into consideration the supply chain length and sensitivity to excess moisture and dehydration is critical.
  • Good box design that enables unimpeded air flow from one side of the pallet to the other.

The promotion of healthy eating and an increasing world population are driving global transactions and the consumption of fruits and vegetables In efforts to make the transactions cost-effective, the reduction of supply chain waste and carbon footprint are driving the increased use of MAP technology to preserve and extend fresh produce shelf life. The successful implementation of MAP necessitates a holistic approach that comprises an understanding of postharvest pathology, physiology, cold chain logistics and the interaction of these factors with packaging design.

Department of Agriculture, Forestry and Fisheries, Republic of South Africa.
Modified Atmosphere Packaging: The Freshest Technology Out There! Gary Ward, Ph.D. Technical Development Manager StePac, Israel.

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