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Preservation
FPE Final Exam
Describe High Temperature Short Time pasteurization. | A product is heated to a particular temperature, held at that temperature, and then cooled to storage temperature. |
T or F: Pasteurization and blanching use lower temperatures than sterilization. | True |
Define pasteurization. | A thermal process used to eliminate specific pathogenic microorganisms in foods. |
Define blanching. | A thermal process used to eliminate specific enzymes in foods. |
____ heat exchangers are usually used in HTST pasteurization. | Plate |
T or F: The FDA does not consider the time spent in the holding tube in a pasteurization system. | False |
Usually a _____ ______ pump is used in a HTST pasteurization system. | positive displacement |
Where is the flow diversion valve located in a HTST pasteurization system? | At the exit of the holding tube. |
In a blanching system, the product is exposed to ____ or _____. | steam, hot water |
T or F: Temperatures for commercial sterilization systems usually exceed the boiling temperature of water. | True |
Name the three types of commercial sterilization systems. | Batch, continuous, aseptic |
T or F: In an aseptic sterilization system, products are sterilized together. | False |
T or F: Aseptic processing systems can be used for solid foods. | False |
For spores, there is a prolonged initial ____ growth phase. | lag |
Define decimal reduction time. | Time needed to achieve a 90% reduction in microbial population. |
What is the slope of a microbial survivor curve equivalent to? | rate constant K |
Exposure to higher temperatures results in _____ slopes of first order curves. | increasing |
Define z-value. | The temperature necessary to cause a 90% reduction in the decimal reduction time. |
Define thermal death time. | The total time required to accomplish a stated reduction in population of vegetative cells or spores. |
What is the typical thermal death time for shelf-stable foods? | 12D - value of C. botulinum |
What is the purpose of commercial sterilization? | To eliminate the need for refrigeration. |