Sterilization continuous heat

The basic raw materials required include starting culture E. coli cells), nutrients (glucose and salts), tryptophan, water, ammonia and air. The process equipment includes fermentor, mixing tank, continuous heat sterilizer, centrifugal compressor, air filter and storage tank. 

The contaminants can also be destroyed by heat. Heat sterilization of media is the most common method used for sterilization of liquid media. This can be accomplished in either a batch or a continuous fashion. 

CONTINUOUS FLOW STERILIZATION Heat Transfer to Shear-Thinning Fluids... 

Chapter 8. Heat transfer in continuous flow sterilization and to canned foods under intermittent agitation. 

Fig. 10 Flow diagram of LAF continuous-belt tunnel for dry heat sterilization and depyrogenization. (From Ref. courtesy of Kluwer.)...

Dry heat should be used only for materials that cannot be sterilized by steam either because the moisture would damage the materials or they would be impermeable to it. There are many complicating factors associated with dry-heat sterilization. The process of steam sterilization is accomplished by saturated moisture in dry-heat sterilization, the moisture can vary considerably. Because of the loss of moisture, the death rate of spores might change with the continued application of heat. ... 

More recent studies confirm the value of added ascorbic acid in wine for improvement of quality (680-683), in champagne production (684), in converting ordinary wine into sherry wine (685), in eliminating the need for heat sterilization of sulfur dioxide (686), and in the production of hot bottled Moselle wine (687). Reports on combined use of ascorbic acid and sulfur dioxide indicate its continued practical significance (688-691). 

Sterilizers can be operated discontinuously or continuously. For engineering-scale processes, sterilization is usually done with heat (i.e., steam) on economic grounds. Chemical and physical processes also exist (Aiba, Nagai, and Nishizawa, 1976 Richards, 1968). The stirred processes differ from each other in method of heat exchange. They are far surpassed for continuous operations by tube-type sterilizers, a consequence of the formal first-order kinetics of sterilization (see Chap. 5). Continuous steam sterilizers have been used for a long time in food processing technology (e.g., milk production). 

The most widely used sterilization method ia the food industry is moist heat. The heat is usually suppHed by high pressure steam, but because most foods already contain moisture the role of steam is to heat the food to the required temperature. The cooking and sterilization processes can frequendy be combined into one. The food may be sealed into impervious containers of glass, metal, or plastic film and undergo terminal sterilization, or it may be presterilized in batches or in a continuous operation and then filled into a presterilized container. The latter process is called sterile filling. 

There are four types of food sterilization processes terminal sterilization in prefiUed containers in a batchwise process terminal sterilization in prefiUed containers of appropriate design heated to the required temperatures in a continuous process aseptic filling foUowing batchwise cooking in an appropriate retort and aseptic filling in a continuous cooking system equipped with appropriate valves to aUow the necessary pressures for attainment of the required sterilization temperatures. 

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