Retort process, description

FIGURE 17.3 Odor intensity and odor description of green tea drinks before and after heating process. Retorting process 121°C, 10 minutes. UHT sterilization 134°C, 30 seconds. Odor intensity of nonheated green tea drink (control) 3. pH 6.2 (control), 5.6 (after retorting process), 6.1 (after UHT sterilization). 

The description given apphes to DR processes that are based on the use of gaseous reductants ia shaft furnaces, batch retorts, and fluidized beds. In the processes that use sohd reductants, eg, coal (qv), the reduction is accomphshed to a minor extent first by volatiles and reduciag gases that are released as the coal is heated and then by CO that is formed by gasification of fixed carbon contained ia the coal char with CO2. Reductioa by sohd carboa and coal volatiles ia kilns is insignificant. 

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