The equipment is relatively inexpensive and mechanically simple. The process consists of a chamber or steam tunnel which is designed to be integrated into a fruit or vegetable process line. The fruit or vegetable enters the chamber, usually on a conveyer, or the produce can be inserted batch mode. Pressurized saturated steam is injected through vents into the chamber to bring the surface temperature up to 74°C. Surface temperature can be monitored by contacting the surface with a thermocouple or by inserting a thermocouple into the produce 6 mm below the surface. Since this might not be reliable or practical in a continuous operation, surface temperature can also be monitored with a remote infrared sensor. After reaching 74° C, steam injection continues for a 60-second hold time. The actual time and temperature can be adjusted, but a surface temperature of 84°C degrades the organoleptic properties of fruits and vegetables. Following the hold period, chilled water at 2 to 5°C quenches the surface for another 60 seconds. The unit comes with its own steam supply and self-contained water system, including chilled water, making it easy to install and operate.
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