Heating Media for Processing Foods in Flexible Packages, Phase II

摘要

The objective of this study was to evaluate and compare steam, steam-air and water heating media for processing flexible packages and to develop suitable procedures for using these heating media in commercial processing equipment. A multipoint temperature recording device which measured the temperature of the heating medium and in the container at various locations was used to evaluate temperature gradients and heating rates for the vertical and horizontal retort and for the steam-air pasteurizer. The temperature distribution pattern and the rate of heating of water in 303x406 cans were determined for 100% steam, 90% steam-10% air and 75% steam-25% air mixtures, and water in a commercial vertical and horizontal retort and for a steam-air mixture in an atmospheric pasteurizer. Steam-air and water were evaluated at air flow rates in the range of 10-30 cfm. Steam and steam-air were evaluated using natural and mechanical circulation. The performance of the 3 heating media were studied in the vertical retort using both a cross and a circular spreader system. Satisfactory control procedures for processing flexible packages in the 3 heating media were developed for both horizontal and vertical commercial retorts. The horizontal retort was found to be a more effective configuration for processing using steam-air mixtures. (Author)