# Freshness Monitoring of Packaged Vegetables
## 7 Challenges, Outlook, and Future Research  
Smart packaging is a powerful way to change the current quality assessment models used for packaged vegetables from \"Use by\" or \"Best Before\" to more dynamic paradigms. However, several challenges and concerns should be carefully considered. One of the major concerns is the safety of the smart systems used with direct contact to food, especially with the possibility to migrate to food. Therefore, the substances used shall pass and comply with all food regulations regarding the material used. In Europe for instance, there are two main regulation standards' 1935/2004/EC and 450/2009/EC to control and enhance the safety of smart packaged vegetables, while the US USFDA regulations are for active packaging materials [105]. In Canada, there is the food and drug act and regulations for food packaging and for materials used. Thus, the authorization to use new materials in labels requires a complex and long process for regulatory approval. This may inhibit companies from investing in this field. Therefore, more cooperation between government agencies and commercial entities are required. Accuracy and robustness of smart sensing systems need to be very high to guarantee public safety and welfare. False positive should be avoided, as having a package labeled safe despite its contamination can cause very serious health and legal problems. The false negative should also be minimized as this is considered an economic loss. New validation techniques and methodologies need to evolve to support testing of such systems. Studies are needed on how the existing systems may be upgraded to improve the quality of smart packaging systems and decrease the number of errors. Sustainability of the smart system used is an important factor due to its huge impact on the depletion of natural resources. However, many components of the smart packaging systems such as  
Figure 18: Working principle of temperature compensating films. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**AP System** & **Commercial Name** & **Packaging Form** & **Reference** \\ \hline O\({}_{2}\) scavengers & ATCO® LH-100 & Labels & [20] \\ Cryovac® OS2000 TM & Film & [205] \\ ATCO® CO-450 & Sachets & [206] \\ CO\({}_{2}\) scavengers & Ageless® & Sachets \& labels & [201] \\ Freshlock® & Sachets & [1] \\ Yome & Sachets & [207] \\ Tyve® & Sachets & [20] \\ Moisture absorbers & Pad-Loc Fresh® & Pads & [1] \\ PichitTM & Film & [1] \\ Temperature & BreatheWay® & Film & [208,209] \\ compensating films & Intellimer® & Film & [210] \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Comparison between different intelligent systems. batteries are not environmentally friendly. Thus, the disposal of these smart sensors or labels must be carefully considered. A potential solution of this challenge is in the development of recyclable technology together with the shift toward integrating bio-degradable materials as part of packaging. Green sustainability, a growing trend in smart packaging, can help in reducing environmental impacts. This concept is relatively new and requires more studies and new regulations. The cost of smart packaging systems is a major limitation for its widespread commercialization. Increasing the unit price of packaged vegetables will not satisfy most consumers. The return-on-investment may then negatively affect manufacturers, inhibiting potential investments in smart packaging technologies. However, the huge food waste in retail and distribution that can be avoided with the use of such technologies. For instance, the outbreaks of _E. coli_ in lettuce in early 2019, lead most traders, manufacturers, and distributers to discard whole batches to avoid the possibility of contamination. This is a big loss that could have been avoided with the use of smart packaging technologies. Risk management may improve with the use of information traced and extracted using real-time monitoring systems that gives more information about the behavior of food.