All liquid foods (water, milk, fruit juice, beer, etc.) contain single cell organisms such as bacteria and fungi. Some of these organisms are pathogenic, posing a health risk if ingested. In developed countries, most liquid foods are pasteurized or chlorinated prior to human consumption as a means to reduce pathogenic organisms. Pasteurization is a thermal process whereby the temperature of a liquid food is rapidly increased for a short period, then rapidly reduced to a temperature suitable for storage and transport.
Chlorination is a chemical process, primarily used for potable water. Both of these processes kill a large fraction of target organisms present in the liquid, typically 99.99%, although the cost of achieving this kill ration is rather high. The health and economic benefits of theses processes are enormous, as is the energy expended. World wide, costs associated with the thermal energy required to pasteurize milk in 2002 were approximately two billion dollars.
An efficient non-thermal, non-chemical means to accomplish a similar effect would represent a great economic benefit, not only to developed societies, but also to underdeveloped countries where thermal or chemical pasteurization is an economic burden or otherwise technically infeasible.
Morphologically, all bacteria and fungi cells share a common structure comprised of a thin phospholipid membrane encapsulating organelles and other cellular machinery suspended in the fluid cytoplasm. These membranes are complex heterogeneous structures separating the living cytoplasm from the extra-cellular environment. Biological membranes are remarkably robust, serving as a structural, chemical, and electrical barrier, while conducting the transmembrane metabolic affairs of the cell.
The integrity of this membrane and its barrier function is paramount to cell viability. If an electric field of sufficient intensity and duration is applied to a living cell, membrane integrity can be severely disturbed, causing mechanical perforation, lysis, and death. This process is known as electroporation. Thus, electroporation can be used as a means of killing microbial organisms.