Sterilization Of Food

Bacteria, yeasts and molds in foods, such as meat, fish and agricultural products, are sterilized by high pressure treatment at 400 - 600 MPa. The pressurization of mandarin or orange juices at 300 - 400 MPa for 10 min is enough to sterilize vegetative microorganic cells, although spores of Bacillus sp. are not killed. This retains good taste and flavor of the juice and allows to store it at room temperature for 5 months. When pressure was applied at 45 °C, the results were considerably better than that at the room temperature (6-10).

Pressurized juice should be preserved under chilled conditions to keep its fresh flavor and taste. Low temperature also helps to reduce the development of precipitates, since low temperature storage keeps pectin esterase activity low; thus, pectin esterase cannot participate in the formation of a precipitate. The low temperature storage is important to other pressure-processed foods; for example, pressure-processed jams being kept cold exhibit fresh taste and flavor for long periods (6-10).

Pressure-sterilization is also useful to retain the taste and flavor of traditional pickles where heat-sterilization deteriorates them. Pressure-sterilization is also useful in fermentation of foods to keep the taste and flavor intact (5-10).

The prominent use of the high pressure sterilization is in partially prepared foods or oven-ready foods. Pressure treatment preserves flavor, taste and natural nutrients, but bacterial spores are not killed (see below). Hence, those foods require chilled transportation.

0 0

Post a comment