# A Full Technological Traceability System for Extra Virgin Olive Oil
## Materials and Methods  
### EVOO Traceability  
The EVOO produced by thirty-three olive trees was followed along the whole supply/processing chain from standing trees to consumer. The olive trees and the olive oil mill production site under study were on the Ponzani Antonio farm, in Montorio Romano (Central Italy; N 42.1395917; E 12.77265). The olive orchard, located in a hilly area, is characterized by a ground with an average slope of 35%, and an irregular planting layout with average distances between the trees of \(10.2\times 8.9\) m, equal to an average density of about 110 trees per hectare. The harvest was conducted between 7 November and 27 November. The olive pressing was conducted on 27 November.  
The EVOO production chain can be summarized in the following technological traceability system (TTS; infotracing) phases (Figure 1):  
* Standing olive tree: application of the first waterproof coin shaped RFID tag with a central hole (RFID1) that was positioned on the trunk in the North direction and fixed with an iron nail (Figure 2A). This first tag was used to provide to the database information related to tree cultivar (Carboncella, Frantoio, Leccino), tree GPS point and other observations (notes). A total of 33 trees (11 trees per cultivar) were tagged.
* Olive harvest: application of the second kind of RFID tag (RFID2), a waterproof flexible band with two holes at the extremities fixed with a small cord on the crate (Figure 2B). The crates were used to transport the harvested olives at the olive oil mill. Each RFID2 was uniquely associated with one tree, thus preserving the association with the RFID1 information applied in the previous phase. Here were added the following information related to each crate: crate weight, olive maturity (high, medium, low), olive defects (high, medium, low) and other information (notes) and type of harvesting (mechanized, semi-mechanized, hand harvesting). In the present work the harvest was entirely semi-mechanized for all the cultivars.
* Olive pressing: information on the yield and type of olive oil extraction process. The extraction system used for the scope was a \"II Molinetto\" compact continuous oil system from Pieralisi group (Ancona, Italy) and a two-phase centrifugal separator from Alfa Laval (Monza, Italy).
* Nutritional information of the olive oil printed on EVOO bottle label such as fats (saturated, monounsaturated, polyunsaturated), carbohydrates, proteins, salt and vitamin E.
* Final product: The QR code tag was printed on the external EVOO bottle label and protected by a \"scratch and win\" system. The \"scratch and win\" system is a gamification method that protects the QR code in order to allow the consumer who buys the product to obtain the reward. The Infotracing platform was implemented with a blockchain system. Once the consumer purchases the product, scratching the label and framing the QR code with a smartphone, he or she can receive, along with the product information, a digital token of \(\copy 0.05\), produced by the blockchain itself, which can be spent on the reference platform. The blockchain system ensures that the information inserted along the entire supply chain is tamper-proof [6].  
* Final consumer: The QR code, once scratched, was scanned by the final consumer, and the infotracing information was read through a web link.  
The point of strength of the proposed TTS system mainly regards the possibility to carry information of any type (specific nutritional, DNA, farm related, etc.) in a safe way (from the standing tree to EVOO bottle). A limited production of bottles was used for experimental and demonstration purposes (100 bottles containing 500 mL each). Four kinds of EVOO were produced: three monocultivars (Carboncella, Frantoio, Leccino) and one blend (PDO Sabina).