Non-thermal atmospheric pressure plasmas for post-harvest application of fruit and vegetable sanitation

Fresh and fresh-cut produce have a limited shelf life of several days, which only allows a short distribution. The limited shelf life and the associated losses of fresh produce have various causes, but particularly depend on a microbial contamination at all stages in the value chain. The microbial contamination may also cause foodborne illnesses, which occur annually and worldwide. Especially, produce like fresh-cut and fresh vegetables and fruits are frequently affected. The U.S. Food and Drug Administration listed them all under the ten riskiest foods in their Center for Science in the Public Interest Report 2009. Whereby leafy greens are on the top. The incidence of all foodborne outbreaks in the USA was enhanced from 0.7 % in the 1970s to 33 % in 2012. The European Food Safety Authority described in their zoonoses report of 2011, 5,648 reported food-borne outbreaks for 2011 with more than 200,000 confirmed human cases. Among others, the outbreaks were caused by Bacillus toxins, Campylobacter, Clostridium, E. coli mainly Verotoxin-producing Escherichia coli and Listeria, Yersinia. Ready-to-eat as well as fresh-cut fruits and vegetables were also contaminated with these microorganisms.In the E. coli outbreaks, 50 % of the involved products were vegetables and juices and other related products, which is most notably traced back to a large outbreak of haemolytic-uraemic syndrome (HUS) and bloody diarrhea associated with shiga-like toxin-producing E. coli (STEC) O104:H4 infections occurred primarily in northern Germany from May to July 2011.? More information (1) Leibniz Institute for Plasma Science and Technology(2) Leibniz Institute for Agricultural Engineering and Bioeconomy SourcesSchnabel, Uta; et al. (2017). Non-thermal atmospheric pressure plasmas for post-harvest application of fruit and vegetable sanitation. Biblioteca Horticultura. Recovered from http://publicaciones.poscosecha.com/es/sanidad-vegetal/359-non-thermal-atmospheric-pressure-plasmas-for-post-harvest-application-of-fruit-and-vegetable-sanitation.html?Com pers Uta Schnabel:Does it exists commercial equipment to provide this kind of disinfection (plasma)?There are some equipments available, however, non of these has been confirmed by legal frameworks,?so you can not buy it commercial. Are the plasma particles able to find a microbe, for instance, if below a leaf?No, the particles do not act actively, they reach the microbes by diffusion processes, so it is also possible,?that they find organic matrix instead of microbes.It is like using ozone gas or UV, you attac everything and hope you find the right process window to have?maximum effect to microbes and minimum to tissue.How does you generate the plasma?Plasma is a partly or completly ionised neutral gas, by adding energy to the gas and therefore getting electrons with more energy, more movement and different properties. That's why you see a light.It can simply be considered as a gaseous mixture of negatively?charged?electrons and highly charged positive?ions, being created by heating a gas or by subjecting gas to a strong?electromagnetic field. However, true plasma production is from the distinct separation of these ions and electrons that produces an?electric field, which in turn, produces?electric currents?and?magnetic fields. Based on the surrounding environmental?temperature?and?density?either partially?ionised?or fully ionised forms of plasma may be produced. Partially ionised plasma is popularly understood, for example, as bright?neon signs?or?lightning storms,?while more fully ionised plasma is associated with the interior of the?Sun,?the?solar corona,?and?stars.In my group, we normally use microwave to add energy, but you can also use high-voltage discharge or radio waves.