Module 11: High Temperature Preservation Flashcards
True or False: The kind of heat for high temperature processing cannot vary.
FALSE; heat can vary
What are the characteristics of MILD HEAT?
- Kills pathogens
- Reduce bacterial count
- Inactivates enzymes
- Minimal damage to flavor, texture, and nutritional quality
- Short shelf life
- Another preservation must be used
What are the characteristics of SEVERE HEAT?
- Kills all bacteria
- Food will be commercially sterile
- Major changes in texture, flavor, and nutritional quality
- Long shelf life
- No other preservation is necessary
- Food is overcooked
True or False: There is such a thing as ‘sterile food’.
False; There is no such thing as sterile food but there is such a thing as commercially sterile food.
What are the six kinds of cooking methods?
- Baking
- Broiling
- Roasting
- Boiling
- Stewing
- Frying
Cooking is a form of what kind of treatment?
Mild Heat Treatment
Why do we cook our food?
- To make food more palatable, improve taste
- Alteration of color
- Improved digestibility
True or False: Cooking is a form of preservation technique.
False: Cooking is not a preservation technique but it destroys or reduces MOs, inactivates enzymes, and destroys toxins.
True or False: Cooking does not give food a long shelf life.
True
What kind of MILD HEAT TREATMENT is applied to tissue systems prior to freezing, drying, or canning?
Blanching
Explain the process of blanching.
- Let the water boil
- Immerse vegetables for a few minutes
- Remove the vegetables
- Immerse in cold water
What does blanching do prior to freezing or dehydration?
- Inactivates enzymes such as (peroxidase and catalase)
What are the four benefits of blanching prior to canning?
- Remove tissue gases
- Increase temperature of the tissue
- Cleanse the tissue
- Activate or inactivate enzymes
What process kills part but not all of the vegetative MOs present in the food?
Pasteurization
What are five examples of supplementing pasteurization?
- Refrigeration
- Packaging
- Anaerobic conditions
- Drying
- Chemical Preservatives
Why is supplementing pasteurization important?
Because after pasteurizing we can add on these techniques to increase shelf life.
What is the process of inactivating microorganisms?
Sterilization
True or False: In sterilization, there is generally no need to remove thermophilic organisms which have no public health significance.
True
What do you call hot loving microorganisms?
Thermophilic
What is Commercial Sterility?
The condition achieved by the application of heat, sufficient alone or in combination with other ingredients and or other treatments to render the product free of MOs capable of growing in the product at non-refrigerated conditions.
What is the requirement for products in terms of storage conditions in Commercial Sterility?
Products should not be stored at a temperature of 32ºC when the MOs will germinate causing product spoilage.
What is the primary objective of commercially sterile foods?
Destroy the most heat resistant pathogenic spore-forming organisms (e.g., C. botulinum in products which > pH 4.6).
Botulinum is a _____________?
Pathogen
What are characteristics of botulinum?
- heat resistant and spore forming
What happens to botulinum when exposed to adverse conditions?
It becomes a heat-resistant spore.
What is the secondary objective of commercially sterile foods?
Destroys vegetative and spore-forming microorganisms that cause spoilage.
Where is C. botulinum spp. found?
Soil and water.
Which bacterium has the ability to produce heat-resistant spores?
Botulism
The spores of C. botulinum causes __________?
Botulism
From the 7 known types of botulism, how many are able to cause illness in humans?
4
To germinate, the spores need the following conditions: a. __________ environment, b. __________ food, c. __________, d. __________.
a. Anaerobic
b. Low-acid
c. 4ºC to 50ºC
d. Relatively high moisture
Explain: If a product is not properly canned, can spores form?
Yes, because if not properly canned, then O2 may still be present in the can, which can lead to spore formation.
How many mice can 1 mg of botulism toxin kill?
655
True or False: Food can contain the botulism toxin without showing any signs.
True
True or False: Antitoxin is available; and recovery is fast.
False; Recovery is slow, and permanent nerve damage may result.
True or False: Spores do not grow in high-acid foods.
True
True or False: Spores are not killed when low acid foods are heated long enough at a specific temp.
False; spores are killed when low acid foods are heated long enough.
What kind of products usually do not contain C. bot?
Fruits
What is the ideal temperature of processing low-acid foods to prevent botulism?
115ºC and above
What instrument is used for all low-acid foods?
Pressure canner
Cite examples of ways to prevent botulism.
- Properly prepare and process food
- Check canner for accuracy and operate it correctly