# How Hydrogen (H\({}_{2}\)) Can Support Food Security: From Farm to Fork
## 3 H\({}_{2}\) in the Storage and Distribution Chain  
The distribution and storage of fresh produce are paramount to ensuring food security with many aspects (e.g., transportation, warehouse and vendor) reliant on controlling the temperature at which foods are stored. The refrigeration process is not only energy-intensive, costly and environmentally taxing [30], but using this preservation method does not prevent, but mitigates, losses of perishable foods. Therefore, to ensure future food security, it is pertinent to consider novel approaches that can further reduce the deterioration rate of valuable produce.  
A broad range of research in animals [11; 31; 32] and plants [33; 34; 35] identifies H\({}_{2}\) as having noticeable reducing properties, which are relevant to the preservation of food products as such redox poise favours a reducing environment, attenuating the accumulative oxidation of lipid components. Lipid oxidation is instrumental in the deterioration of biological substances as it can diminish cell membrane integrity, resulting in ion leakage, dysfunctional organelle activity and aberrant cellular cohesion [36; 37]. Preventing lipid oxidation is a leading consideration for increasing the longevity and nutritional value of food products [9; 10].  
To date, research into H\({}_{2}\) describes the molecule as an effective mediator of cellular homeostasis, albeit the precise mode of action has yet to be delineated. Many reports highlight a direct scavenging effect of such ROS/RNS as the hydroxyl radical (\({}^{\bullet}\)OH) and peroxynitrrite ion (ONOO\({}^{-}\)) [38; 39; 40], both significant contributors to lipid oxidation. However, considering the spatial and temporal distribution, and the kinetics of these highly reactive molecules, whether such reactions occur in vivo is questioned [41; 42]. Alternative mechanisms of action involving the partial reduction in Fe\({}^{3+}\) moieties [43] and protein stabilisation [44] have been proposed, and whilst the modality of H\({}_{2}\) is currently a matter of academic debate, what is clear is that implementation of HRW and H\({}_{2}\) gas to post-harvest produce consistently demonstrates an increased resistance to ripening, senescence and spoilage in fruits, herbs and vegetables (Table 1).  
In addition to postharvest treatments, preharvest irrigation with HRW has also been demonstrated to protect natural produce against storage-related chilling injury [52]. This indicates that the application of H2 has long-lasting, positive effects on plant biochemistry. As is shown in Table 1, H2 has pleiotropic effects in plants, from regulating the activity of endogenous antioxidants including ascorbate peroxidase (APx), catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) [34], to reducing biomarkers of senescence \(\beta\)-Galacosidase (\(\beta\)-Gal), peptidoglycan hydrolase (PG) and pectin methylesterase (PME) [47] and increasing the biosynthesis of such polysaccharides as cellulose and pectin [49]. It is conceivable that, together, these cytoprotective qualities can further prevent the deterioration of fresh produce in storage and transit.  
Incorporation of H2-producing technologies into established storage and distribution chains will require careful consideration due, in part, to the possibility of igniting H2 [53], a highly explosive gas, and to the time involved in washing and subsequently drying produce. Additionally, although the preparation of HRW baths is a relatively simplistic process [45; 50], with a large volume of produce the process could become labour-intensive. Therefore, it may be prudent to focus on the pre-harvest and processing/packaging applications of H2.