User:AKASH S PAWAR

High pressure food processing

The idea of high pressure food processing is not new, the first research in high HPP is now more than a century old. In the late 1800s scientists conducted an experiment to see the effects of high pressures on bacteria; the findings showed that stresses up to 600MPa can indeed kill them. Basically the process is just the application of high isostatic pressures between 100 and 1000 MPa. The preferred hydraulic fluid used in this process is water because of its compatibility with food substances. Gas can also be used as a medium, but from an engineer’s point of view it is almost non-compressible fluid, therefore can store a lot of energy, and can be extremely hazardous with the failure of the pressure container. However water can store much less energy, thus risks from explosions are significantly lowered. HPP maintains the quality, freshness of the food and also extends its self-life. The process is also known as high hydrostatic pressure processing (HHP) and ultra high-pressure processing (UHP). Since most common ways of killing bacteria is by heat treatment, which can reduce product quality, by eliminating thermal processing, HPP has a minimal effect on the freshness of foods, resulting in better taste, nutrition content, and appearance, thus technology is extremely beneﬁcial for heat sensitive products. High pressure processing can also destroy bacteria that can cause spoilage without a loss of nutrients or quality. In a HPP process, the product is enclosed in a ﬂexible container (usually a small bag or plastic bottle) and loaded into a high pressure vessel ﬁlled with a hydraulic ﬂuid (normally water) the pressure is then passed on to the food itself. After the system has reached the desired pressure, products are  for a speciﬁc time, normally 3 to 5 minutes then the vessel is depressurized, the processed product is then removed and stored/distributed. Since the pressure is applies simultaneously and uniformly in all directions,...