Water is an essential component of food structures and biological materials. The importance of water as a parameter affecting virion stability and inactivation has been recognized across disciplinary areas. The large number of virus species, differences in spreading, likelihood of foodborne infections, unknown infective doses, and difficulties of infective virus quantification are often limiting experimental approaches to establish accurate data required for detailed understanding of virions’ stability and inactivation kinetics in various foods. Furthermore, non-foodborne viruses, as shown by the SARS-CoV-2 (Covid-19) pandemic, may spread within the food chain. Traditional food engineering benefits from kinetic data on effects of relative humidity (RH) and temperature on virion inactivation. The stability of enteric viruses, human norovirus (HuNoV), and hepatitis A (HAV) virions in food materials and their resistance against inactivation in traditional food processing and preservation is well recognized. It appears that temperature-dependence of virus inactivation is less affected by virus strains than differences in temperature and RH sensitivity of individual virus species. Pathogenic viruses are stable at low temperatures typical of food storage conditions. A significant change in activation energy above typical protein denaturation temperatures suggests a rapid inactivation of virions. Furthermore, virus inactivation mechanisms seem to vary according to temperature. Although little is known on the effects of water on virions’ resistance during food processing and storage, dehydration, low RH conditions, and freezing stabilize virions. Enveloped virions tend to have a high stability at low RH, but low temperature and high RH may also stabilize such virions on metal and other surfaces for several days. Food engineering has contributed to significant developments in stabilization of nutrients, flavors, and sensitive components in food materials which provides a knowledge base for development of technologies to inactivate virions in foods and environment. Novel food processing, particularly high pressure processing (HPP) and cold plasma technologies, seem to provide efficient means for virion inactivation and food quality retention prior to packaging or food preservation by traditional technologies.

This study was conducted to investigate the growth of microorganisms, including pathogenic bacteria such as Cronobacter sakazakii and Bacillus cereus, in Sunsik beverages made of water, milk, soymilk, or honey-water during storage at room temperature. Prepared Sunsik beverages were stored at room temperature and the growth of total aerobic counts, Escherichia coli/coliforms, and yeast and mold were measured. Also, samples inoculated with a cocktail of C. sakazakii or B. cereus spores were stored at room temperature and their growths were determined during storage. Populations of total aerobic counts and coliforms significantly increased with increasing storage time at room temperature, which resulted in higher than 8 log and 7 log after 24 h in all samples except for the honey-water sample, respectively. Levels of total aerobic counts and coliforms were significantly lower in the honey-water sample than in the other samples after 6 and 9 h of storage, respectively. Initial populations of C. sakazakii and B. cereus ranged from 0 to 1 log CFU/mL, respectively, and these populations significantly increased with increasing storage time at room temperature. Therefore, populations of C. sakazakii and B. cereus were approximately 7 to 8 log CFU/mL after 24 h of storage. However, after 12 and 9 h of storage, there were significant differences in levels of C. sakazakii and B. cereus between the honey-water sample and the other samples, respectively. Based on these results, the addition of honey can inhibit microbial growth in Sunsik beverages; however, the best way to avoid pathogen infection would be to consume Sunsik beverages as soon as possible after preparation.

Plasma-activated water (PAW) is a novel and promising alternative to traditional food sanitizers. Recently, the inactivation efficacy of PAW has been demonstrated on a wide range of food products against foodborne pathogens, spoilage microorganisms, and harmful chemicals. The effectiveness of PAW relies on various factors related to the plasma generation mechanisms, the target microorganisms, and the food matrix. The inactivation mechanisms of PAW are attributed to the damage of cell integrity and intracellular components by various reactive oxygen and nitrogen species (RONS). Utilization of plasma-activated liquids and hurdle technologies can enhance the inactivation efficacy and diversify the application of this technology. Scaling-up of PAW is still at the very beginning stage and needs further studies before industrial application.

The Maltese Islands food-water-energy nexus faces substantial challenges. These include increasing levels of land fragmentation and abandonment, an aging farming population and decreasing returns possible for remaining, often part-time, farmers. Demand for high quality, locally produced vegetables and seafood from natives, tourists and migrants continues to increase while production shrinks in the context of a rich traditional food culture. The country’s aquaculture sector also faces serious obstacles with exports facing tough competition and the tuna fattening industry dwindling because of reduced quotas. Water resources are also very scarce. Malta has no lakes or rivers and ground water is becoming increasingly brackish because of over-extraction, In terms of water resources per inhabitant, Malta is the most water stressed country in Europe and one of the ten most water-short countries in the world. Domestic supply of water is highly dependent on desalinization – an energy intensive process. Moreover, 90% of groundwater is of poor status and unfit for drinking because of nitrate pollution. This paper uses Malta as a case study to scope the potential of aquaponics to meet the complex demands of an economy with a high standard of living but extreme water-scarcity. Aquaponics – a closed cycle, soil-less method of cultivating crops that is highly water efficient and can reuse the limited effluents from intensive fish culture as a nutrient source, is assessed.