Simulation of continuous sterilization of fluid food products: The role of thermorheological behavior of starch dispersion and process optimization.

摘要

The technology of continuous sterilization of fluid food products is currently of great interest to industry because of the potential for producing high-quality food products, increased convenience, and packaging cost reduction. Due to the drastic change of viscosity of the starch-containing fluid foods during gelatinization under the conditions of thermal processing, the fluid flow and heat transfer inside the heat exchanger will be strongly affected by the presence of starch. The design of the processes, therefore, requires accurate information on the rheological characterization of such food products.;The aim of this dissertation research was to develop a better understanding of the flow and heat transfer of a starch-containing fluid food in relation to sterilization in a tubular heat exchanger. Study of the thermorheology of the starch dispersion (STD) and the gelatinized starch paste under the conditions of thermal processing provided mathematical models to accurately characterize the behavior of starch-containing fluid foods during thermal treatment. The computer simulation thus used more realistic rheological properties than the previous studies and it provided insights into the complex process systems that were difficult to understand in the past.;In the simulation of aseptic processing, two tube diameters (0.018 and 0.024 m), two heating wall temperature (139 and 145