in the air we breathe to 1 percent or 2 percent. Temperatures are kept at a constant 0 to 2 C (32 to 36 F). Humidity is maintained at 95 percent and carbon dioxide levels are also controlled. Exact conditions in the rooms are set according to the apple variety. Researchers develop specific regimens for each variety to achieve the best quality. Computers help keep conditions constant." "Eastern Washington, where most of Washingtons apples are grown, has enough warehouse storage for 181 million boxes of fruit, according to a report done in 1997 by managers for the Washington State Department of Agriculture Plant Services Division. The storage capacity study shows that 67 percent of that space enough for 121,008,000 boxes of apples is CA storage." [15]Air-tight storage of grains (sometimes called hermetic storage) relies on the respiration of grain, insects, and fungi that can modify the enclosed atmosphere sufficiently to control insect pests. This is a method of great antiquity,[16] as well as having modern equivalents. The success of the method relies on having the correct mix of sealing, grain moisture, and temperature.[17]A patented process uses fuel cells to exhaust and automatically maintain the exhaustion of oxygen in a shipping container, containing, for example, fresh fish.[18]Nonthermal plasma[edit]Main article: Nonthermal plasmaThis process subjects the surface of food to a "flame" of ionized gas molecules, such as helium or nitrogen. This causes micro-organisms to die off on the surface.[19]High-pressure food preservation[edit]Main article: PascalizationHigh-pressure food preservation or pascalization refers to the use of a food preservation technique that makes use of high pressure. "Pressed inside a vessel exerting 70,000 pounds per square inch (480 MPa) or more, food can be processed so that it retains its fresh appearance, flavor, texture and nutrients while disabling harmful microorganisms and slowing spoilage." By 2005, the process was being used for products ranging from orange juice toguacamole to deli meats and widely sold.[20]Biopreservation[edit]3D stick model of nisin. Somelactic acid bacteria manufacture nisin. It is a particularly effective preservative.Main article: BiopreservationBiopreservation is the use of natural or controlled microbiota or antimicrobials as a way of preserving food and extending its shelf life.[21] Beneficial bacteria or the fermentation products produced by these bacteria are used in biopreservation to control spoilage and render pathogens inactive in food.[22] It is a benign ecological approach which is gaining increasing attention.[21]Of special interest are lactic acid bacteria (LAB). Lactic acid bacteria have antagonistic properties that make them particularly useful as biopreservatives. When LABs compete for nutrients, their metabolites often include active antimicrobials such as lactic acid, acetic acid, hydrogen peroxide, and peptide bacteriocins. Some LABs produce the antimicrobial nisin, which is a particularly effective preservative.[23][24]These days, LAB bacteriocins are used as an integral part of hurdle technology. Using them in combination with other preservative techniques can effectively control spoilage bacteria and other pathogens, and can inhibit the activities of a wide spectrum of organisms, including inherently resistant Gram-negative bacteria.[21]Hurdle technology[edit]Main article: Hurdle technologyHurdle technology is a method of ensuring that pathogens in food products can be eliminated or controlled by combining more than one approach.