No rotten fruit today please!

by Gary Hartley on 2010-11-29

Many food products are easily perishable. Their storage for more than a day or two and their transport to market can require careful control of temperature and/or humidity. Spoiled fruit, vegetables, meat, fish or dairy products are worthless

That’s a statement of the blindingly obvious for many industries, our beloved kiwifruit being one example. Last year New Zealand supplied around 55 countries with $1.5 billion worth of kiwifruit mostly over a seven-month harvest and export season, relying on a complex supply chain of pack houses, cool stores and time-critical shipments. Keeping the produce chilled and in an optimum state for ripeness on the supermarket shelf is a major focus for everyone in the supply chain. Think of how quickly those hairy berries can go unpleasantly soft in the fruit bowl at home!

What is not so obvious in the perishable food industries is how to be certain that temperature and/or humidity have stayed within necessary parameters over weeks, or months, as the produce is stored, trucked, shipped or air freighted, perhaps across the globe. Chiller technology is sophisticated but conditions can still vary wildly during various supply chain activities. How can we monitor temperature and/or humidity continuously to detect when and how spoilage is occurring, or might be about to occur? That would be pretty useful information if you wanted to take urgent action, or improve things for the next consignment.  Everyone wants to cut waste, not to mention avoid the dissatisfaction and even health issues that could arise if a tray of over-ripe fruit or carton of rotting fish did reach consumers.

No wonder food industries worldwide have a growing interest in sensor-equipped RFID tags that automate the collection of environmental data and send out alerts if there is a problem. Companies can link RFID tags with cellular or satellite communications technologies on trucks, trains, planes and ships to monitor storage and transit conditions for food in real time, or near real time. The tags can be set to trigger alerts when they sense deviation from required levels of cool and/or humidity.

Producers, marketers and distributors can make valuable use of such real-time information, depending on the type of food and supply chain. Perhaps they can rapidly adjust the temperature setting in a container, or reroute produce to a market which is closer for more rapid sale. It might be a matter of changing “use by” dates on meat or alerting a retailer to shift some boxes of fruit onto their shelves ahead of others. Under any scenario, sensor-equipped tags and long-distance communications are a big step on from the current use of digital data loggers to monitor temperature and humidity inside containers on a periodic basis: The data is retrieved later, with much less capability to heed indications of perishable food being endangered.

The economic benefits of reduced food wastage in supply chains are obvious. It can be a national issue for countries that import a high percentage of the fresh produce they consume, South Korea for example. In that country, 25 per cent of all imported perishables are reportedly tossed out before reaching retail store shelves. The South Korean government is sponsoring trials on continuous temperature monitoring of imported foods through the sensor-tagging of containers from the place of origin, through to the end of the supply chain in Seoul, Incheon or Changwon.   

Closer to home, Zespri International’s latest annual review lists nine areas of R&D in our kiwifruit industry, including “supply chain performance” where money is being put into the development of tools and processes to maintain fruit quality and reduce fruit losses. Parts of the industry are already experiencing the benefits of RFID for efficient storage and movement of kiwifruit pallets in the packhouse environment. It is safe to predict that the industry’s taste for innovation will, at some stage, encompass sensor-tagging to monitor the environments in which fruit is stored and shipped to markets around the world (including South Korea).

As with all RFID, tag technology is developing rapidly and changing the value equation around particular applications. For temperature and/or humidity monitoring, the focus is on so-called active or semi-passive tags: Each has a battery to power its collection of data and, in the case of active tags, to initiate an alert message when necessary (semi-passive tags respond to signals from an RFID reader, which may be handheld or programmed to operate automatically at specific intervals). Active tags are better for real-time monitoring. Tags vary also in respect of data storage capacity and read distance, with some ultra high frequency (UHF) capable of tags sending their information 20 feet or more.

Manufacturers of UHF semi-passive tags and readers are beginning to emerge on the world scene and the hardware is being made to comply with the EPC Gen 2 suite of UHF RFID standards used in most global supply chains. The soon to be released semi-passive tags are touted to cost as little as USD$10 – 15 per tag when purchased in volume.

Sensor-equipped RFID tagging is definitely a technology of the future in a world where demand for perishable foods – many of them fresh and from the other side of the world – is rising every year. As a country that lives by food exporting, New Zealand needs to be across the developments, and perhaps helping to lead them.

By Gary Hartley of GS1 New Zealand
http://www.gs1nz.org