Strawberry Grower Deploys RFID to Fix Temperature Troubles

By Claire Swedberg

Sept. 9, 2009—Bionest, a Spanish grower of organic strawberries, is deploying an RFID solution enabling the company to view the temperature of the strawberries packed at its processing facility, as well as record temperature fluctuations in a truck while the berries are transported, and monitor the temperature in real time once more at a retailer's distribution center (DC) in Germany.

Temperature fluctuation of fresh produce during shipment is rarely transparent, and can result in spoilage. (The optimum temperature for strawberries is between 2 and 4 degrees Celsius, or 37 and 39 degrees Fahrenheit.) As a result, produce suppliers and retailers have had to accept a large percentage of produce that has become unsellable at some point between the time it was picked and when it reaches store shelves.

Before loading trays of strawberries onto pallets, Bionest placed SmartPoint tags on top of the trays.

Consequently, Bionest seeks to resolve some "big temperature troubles during transport," says Thomas Cera, the strawberry grower's sales manager. Bionest piloted the technology on a limited number of shipments during the 2009 Spanish strawberry season (February to May), and intends to install it as a permanent deployment for the 2010 season. The solution was provided by Dutch RFID firm Ambient.

The grower hopes to improve its monitoring of temperature changes, and thereby catch temperature problems as they happen. In addition to saving products that might be approaching the high-temperature threshold (4 degrees Celsius), Bionest wants to ascertain where the temperature problems occur.

Bionest typically loads trays of strawberries onto pallets and ships them on the same day they are picked. During the pilot, pallets were tracked from the Bionest facility near Seville, in southern Spain, to the German retailer's DC near Cologne (the retailer has asked Bionest not to reveal its name). Several shipments were tracked each week, with multiple pallets tagged and read throughout the transport per shipment. Before loading the pallets onto trucks, Bionest placed Ambient's SmartPoint tags on top of the trays of fruit, which were then moved through a precooling process before being shipped on the same afternoon.

Ambient's Product Series 3000 is based on the IEEE 802.15.4 standard, on which ZigBee is based. Each SmartPoint tag has a 2.4 GHz RFID chip, antenna and battery, as well as a temperature sensor certified as compliant with the EN-12830 standard, the European norm for temperature recorder devices in the food supply chain. Although Ambient and ZigBee systems are both based on IEEE 802.15.4—and, as a result, share some common features (both operate at 2.4 GHz, for instance, and provide a data rate of 250 kilobits per second)—they are also different from each other. SmartPoint tags, for example, have the capability to determine their own location in a network (in three-dimensional coordinates), using a combination of RSSI (received signal strength indication) and other techniques to calculate their own position.

The SmartPoint tags communicate with Ambient's wireless mesh network, which consists of other SmartPoint tags, as well as Ambient MicroRouters, which receive the tags' signals and transmit the tags' data, along with their own location, to a GateWay reader that, in turn, forwards the information to a back-end server.