## 5 Commercial Solutions  
While scientific research regarding blockchains and traceability in agriculture supply chains is growing rapidly, the same is not reflected in the availability of commercial applications. One of the most celebrated relevant applications is IBM Food Trust. IBM Food Trust was tested with the collaboration of Walmart in order to trace the provenance of mango and Chinese pork products. It is built on the Hyperledger Fabric platform where all data are stored on blockchain ledgers and are accessible throughout the entire supply chain from producer to consumer. An indicative advertised outcome of IBM Food Trust is that the process of identifying a mango's provenance could take seven days of tracking without the Food Trust system, whereas with the Food Trust, it took approximately around 2.2 s [89; 90].  
Provenance is another company that promotes a blockchain-based traceability system for fish products [91]. Through the company's proposed application, every fish product is tagged uniquely. This unique ID contains all the information about the fish, its packaging, transportation and storage conditions. The aim of Provenance is to reduce the double certification costs and provide trustworthy information to consumers by using an immutable distributed ledger system. Provenance utilizes a public blockchain where all the stakeholders are equal, and the information security is high.  
Following the leading steps of IBM's Food Trust and Provenance, nowadays, more and more startup companies emerge in the territory of blockchain-supported agri-food traceability. For example, the AgriOpenData product aims to guarantee, in a transparent, secure and public manner, the traceability of the whole agri-food chain, as well as the processing of agricultural products, especially BIO (biological- in Europe often used as synonym to organic) and DOCG (denomination of controlled and guaranteed origin) products, allowing them to certify the quality and their digital  
\begin{table}
\begin{tabular}{c c c} \hline
**Agriculture Sector** & **Agriculture Product** & **Research Works** \\ \hline \multirow{4}{*}{General agriculture supply chain} & Farming products & [23; 26; 32; 40; 68] \\  & Crops & [42; 43] \\  & Not specified & [22; 44; 49; 65] \\  & Bananas & [51] \\  & Cacao and chocolate & [71; 72] \\  & Eggs & [37] \\  & Fresh fruit and vegetables & [10] \\  & Grains & [34; 55] \\  & Grapes (table grapes) & [53] \\ Agri-food & Maize & [56] \\  & Pasta (Spaghetti) & [54] \\  & Peppers & [57] \\  & Rice & [41; 73] \\  & Tea & [62] \\  & Wheat, corn or soybean & [31; 52] \\  & Not specified & [24; 27; 28; 29; 30; 36; 45; 47; 48; 60; 61; 70; 78] \\ Beekeeping & Honey products & [46] \\  & Salmon (wild salmon) & [38] \\ Fishing & Tuna & [63; 67] \\  & Fish (general) & [35; 50; 51] \\  & Chicken & [25; 58; 69] \\  & Halal meat & [39] \\ Livestock & Pork & [79] \\  & Turkey & [64] \\  & Meat (misc.) & [10; 51; 59] \\ Timbering & [33] & \\ Vnification & [29; 66] & \\ \hline \end{tabular}
\end{table}
Table 3: Applications of blockchain technology for traceability across different agriculture sectors and products.  
identities though a blockchain implementation [92]. Some of the companies that conduct business in this context, and with very similar functionalities and characteristics, are shown in Table 4.