Invisible Guard

Food safety inspectors will be tuning in to enforce the strict new food safety law that just came into force on June 1. One of the tools they will rely on to get the job done is in the form of radio frequency identification (RFID) tags, chips using radio waves to identify and track products.

RFID tags are used to replace the ubiquitous barcode system that requires contact or close proximity to work. RFID data can be read through the human body, clothing and non-metallic materials. The tags can also be reused many times and can withstand heat and dirt.

The RFID tag's characteristics give it the upper hand over barcoding when tracking food production from raw materials and processing to transportation and storage. The information of production chain associated with a piece of food can be recorded onto RFID tags, which can help to trace problems before consumption. Authorities hope this technology can help to build a better regulated food market.

In 2003, early in China's application of radio frequency technology to food tracking, the country attached RFID tags to fish raised in Qiandao Lake, Zhejiang Province. It was the first time China tagged fish products, which enabled customers and market administrators to track the food from water to table.

A basic RFID system needs four components to work: a transponder tag, a transceiver reader, an antenna attached to the reader and software that allows the tag to give its information to a computer.

The transponder tag holds unique identifying information. The transceiver reader emits and receives radio wave communication through its antenna and passes tag information to a computer attached to it.

The radio wave sent by the reader has the power to activate any tags nearby, which then emit their unique identifying information. The response is picked up by the antenna, sent to the reader and passed to the software that makes sense of it. The software, called middleware, can sort thousands of tag signals and makes it available on a computer for record keeping, analysis and management.

Revolutionalizing the Expo

The World Expo 2010 Shanghai will last 184 days and attract around 70 million visitors from more than 200 countries and regions. A paper co-authored by Wen Xuesong and Huang Guanwei of the Sino-German College at Shanghai-based Tongji University said food safety would be a major measurement of success for such a gigantic event. According to the authors, Shanghai should establish a food safety system consisting of monitoring, warning and emergency response, which covers the material production bases, processing plants and information management. The paper said RFID technology would play a vital role in this system.

To ensure the Expo's food safety, the paper said, a food production tracking system should be introduced to track food origins in a complicated multi-layer supply network. The system supplied for the Expo should cover every step from production to consumption. "The adoption of RFID tags is an effective tool to track food origins since it can record point of production and every processing step. Thus we could track down the origins of all the foods sold at the Expo," wrote the paper.

The paper said the Expo's daily food demands would change based on the number of visitors, their nationalities and the weather. Officials estimate that around 400,000 visitors will attend the Expo every day. "Using RFID tags will enable us to learn real-time food sales information, including the total sales and varieties," the paper stated. The authors said that on the one hand, the information could enable the Expo organizer to accurately stock retail outlets; on the other hand, the information could enable accurate food demand predictions, shorten supply cycles and cut down on food storage expenses. "The food supply chain using RFID technology that can respond quickly to customers' demands will bring services closer to visitors' actual demands and increase their overall trust and enjoyment while at the Expo," the paper said.

The food supply chain is a complicated and multi-layered dynamic system, the authors wrote. Therefore, information integration holds the key to the efficient operation of the whole supply chain. In the traditional food supply chain, human errors made while collecting and checking product information can often lead to inaccuracies and lower work efficiency, making it impossible for information to be integrated along the whole food supply chain. The introduction of RFID technology has replaced traditional manual labor with automatic operations, substantially raising the efficiency and accuracy of information collection, reducing information loss during product transport, enhancing decision-making while planning the food supply chain and providing the possibility of information integration.

The authors wrote that a supply system specially designed for the World Expo 2010 Shanghai would use RFID tags to record food product information, including production, storage, transportation and sales data. Sales information on RFID tags can help managers to quickly adjust their delivery and storage volume and switch products between different retail outlets. Moreover, food safety can be guaranteed since the origin of every food item can be traced.

During food production and processing, an RFID tag will be affixed to every batch of raw materials during the transit from its source to a processing plant. Before the material is put onto the production line, every RFID tag will be scanned and basic information like the place of origin and planting and harvesting times will be read and stored in a database. The database can be used for future tracking if necessary. After going through production, a tag will once again be attached to the final product, which incorporates all the information from the raw materials as well as that from processing. The products will be packaged and put on trays with RFID tags before being delivered or stored in a warehouse.

When being stored, products will have their RFID tags on trays scanned by an information system, which can obtain the storage history, destination and expiration date of every item or the entire package. The information system can automatically check-in products and register information into the warehouse database. Moreover, the information system can accurately monitor the stockpile volume. When the volume drops close to or lower than the safety line, the system will automatically send out a reminder and an ordering plan matching the current shortages. The stockpile's manager will confirm the new order before it is sent out.

The paper stated that during food delivery, an information system would come up with a detailed replenishment plan for retail outlets according to their sales records. After the new replenishments arrive, their RFID tags will be scanned, which will transfer their information into the reserves database. Since tourists will change very fast, so will the structure of food purchases change. To avoid selling out a food item at one outlet, the information system can automatically send out warning messages when reserves drop below a certain level. Retail managers would be able to quickly arrange replenishment or call for transport of an item from one outlet to another.

Outlet clerks would scan information for products before putting them on shelves, the paper said. When selling food to customers, clerks would scan the RFID tags on products and on buyers' Expo tickets so that purchasing information could be recorded and the sales database could help to guarantee timely replenishment.