Thermal Food Processing

336 Thermal Food Processing: New Technologies and Quality Issues
The customer eating trends and the food retail trends (such as Wal-Mart) are
the key drivers on impacting the canning industry. Today’s consumer requires
foods to be safe, fresh-like in quality, healthy, nutritional, novel, ethnic, and
convenient. The most pervasive consumer trend in the food industry is the increasing
demand for convenience foods. The general trend of the average meal preparation
time in the U.S. has fallen from 30 to 15 min. 2 Convenience and quality
are the primary drivers that strongly affect every aspect of the food canning
process, including food formulation, packaging, and processing. In this section,
we are going to discuss the recent development in the sterilizer systems for thermal
processing of canned foods, the latest thermal process calculation methods, and
computer-based thermal process real-time control methods for ensuring food safety
and quality.
11.2 CURRENT CANNING STERILIZATION SYSTEMS
The basic flowchart of canning operation is shown in Figure 11.1. The food is
formulated first and filled into a container. The container could be a metal container,
glass jar, plastic bottle, retort pouch, etc. After filling, the container is
hermetically sealed. The sealed product then undergoes a sterilization (or pasteurization)
process to obtain the scheduled food safety (commercial sterility or desired
lethality F z Tref value) and the desired quality. The sterilization process is the critical
control point for ensuring food safety. The sterilizer should be able to consistently
deliver the commercial sterility to every canned product from batch to batch.
There are many types of sterilizers or retorts used in the canning industry. 3,4
The most common sterilizers used in the canning industry are batch retorts,
Raw Ra w
Packaging
Pack agi ng
Preparation
Convert
Food product
Combine
Package
Filling Closing
Sterilization
Shelf
stable sta ble
FIGURE 11.1 The general flowchart of canning process and canned foods in various
package formats.