Date of Award
Master of Science
Food Science and Technology
M. R. Johnston
I. E. McCarty, Jimmy L. Collins
This research project was designed to evaluate the effects on chocolate-flavored drink of two thermal processes and subsequent storage at three different temperatures. Each process was conducted in both still and rotating retorts. Process A was designed to approximate a conventional process using an initial temperature (IT) of 150°F, a retort temperature (RT) of 248°F, and a holding time (BB) of 20 minutes. The samples in this process received no supplemental cooling. Process B was calculated to produce a sterilizing value of eleven (Fo = 11). An initial temperature (IT) of 170°F, a retort temperature (RT) of 245°F, and a holding time (BB) of 37 minutes were used. This process also incorporated a cooling cycle. Samples from both processes were stored at 10°C, 33°C, and 55°C with evaluations being made at the end of 24 hours, 7 days, and 14 days. Samples from both processes were subjected to microbiological analyses as well as to evaluations of pH, color, soluble solids, vacuum, and taste. In this experiment both processes yielded a product that was free of microbial contaminants. The factors of pH and color were affected according to the severity of the thermal processes. The pH values decreased with increases in storage temperature and/or time.
Kelly, Maury Britton, "The interaction of thermal process and storage on the quality of chocolate-flavored beverages. " Master's Thesis, University of Tennessee, 1972.