UHF-RFID solutions for logistics units management in the food supply chain

The availability of systems for automatic and simultaneous identification of several items belonging to a logistics unit during production, warehousing and delivering can improve supply chain management and speed traceability controls. Radio frequency identification (RFID) is a powerful technique that potentially permits to reach this goal, but some aspects as, for instance, food product composition (e.g. moisture content, salt or sugar content) and some peculiarities of the production environment (high moisture, high/low temperatures, metallic structures) have prevented, so far, its application in food sector. In the food industry, composition and shape of items are much less regular than in other commodities sectors. In addition, a wide variety of packaging, composed by different materials, is employed. As material, size and shape of items to which the tag should be attached strongly influence the minimum power requested for tag functioning, performance improvements can be achieved only selecting suitable RF identifier for the specific combination of food product and packaging. When dealing with logistics units, the dynamic reading of a vast number of tags originates simultaneous broadcasting of signals (tag-to-tag collisions) that could affect reading rates and the overall reliability of the identification procedure. This paper reports the results of an extensive analysis of the reading performance of UHF RFID systems for multiple dynamic electronic identification of food packed products in controlled conditions. Products were considered singularly or arranged on a logistics pallet. The effects on reading rate and reading zone of different factors, among which the type of product, the number and position of antennas, the field polarization, the reader RF power output, the interrogation protocol configuration as well as the transit speed, the number of tags and their interactions were analysed and compared

Open problems in traceability: from raw materials to finished food products

Even though the main EU regulations concerning food traceability have already entered to force since many years, we still remark very wide and impacting product recalls, which often involve simultaneously large territories and many countries. This is a clear sign that current traceability procedures and systems, when implemented with the only aim of respecting mandatory policies, are not effective, and that there are some aspects that are at present underestimated, and therefore should be attentively reconsidered. In particular, the sole adoption of the so-called “one step back-one step forward traceability” to comply the EC Regulation 178/2002, where every actor in the chain handles merely the data coming from his supplier and those sent to his client, is in fact not sufficient to control and to limit the impact of a recall action after a risk notification. Recent studies on lots dispersion and routing demonstrate that each stakeholder has to plan his activities (production, transformation or distribution) according to specific criteria that allow pre-emptively estimating and limiting the range action of a possible recall. Moreover, these new and very recently proposed techniques still present some limits; first of all the problem of traceability of bulk products (e.g. liquids, powders, grains, crystals) during production phases that involve mixing operations of several lots of different/same materials. In fact, current traceability practices are in most cases unable to deal efficiently with this kind of products, and, in order to compensate the lack of knowledge about lot composition, typically resort to the adoption of very large lots, based for instance on a considered production period. Aim of this paper is to present recent advances in the design of supply chain traceability systems, discussing problems that are still open and are nowadays subject of research