Term
| FDA defines foods requiring ______ as being potentially hazardous. Why? |
|
Definition
-requiring temperature control
-b/c these foods provide an environment conducive to microbial growth UNLESS other controls are taken |
|
|
Term
| What are the 4 general means to reduce/control commercial food risk? |
|
Definition
1) refrigeration/freezing
2) lower pH: FDA pH break point for low acid food is 4.6
3) reduce water activity: dehydration, solutes, lower temp
4) reduce/eliminate pathogens: cooking, canning, pasteurization, irradiation |
|
|
Term
| What is food water activity? |
|
Definition
-the amount of water available to support bacterial growth
-NOT the sampe as water content
-Aw = p / po : the ratio of H2O vapor pressure of the food (p) to that of pure water (po) at the same temp
-Aw = how much water product will release (% humidity if stored in a sealed bag) |
|
|
Term
| What is the optimal Aw to prevent growth of Staph aureus and mycotoxin-producing fungi? What is the optimum Aw for E. coli & Salmonella? |
|
Definition
-less than or equal too 0.85
-0.95 |
|
|
Term
| Microorganisms can remain viable but do not multiply at Aw < ___ |
|
Definition
|
|
Term
| Water activity can be lowered by what three methods? |
|
Definition
-removing water (dehydration)
-adding solutes (causing water to be bound)
-lowering temp (lowering relative humidity) |
|
|
Term
| How is canning accomplished? What indicates failure? |
|
Definition
-cooking (sometimes under pressure) to kill pathogens and then sealing hte food to prevent introduction of air or pathogens
-expansion/bulging of can or lid indicates failure |
|
|
Term
| What is of the indicator organism the commercial canning process? |
|
Definition
| -Bacillus stearothermophilus |
|
|
Term
| How does irradiation work for reducing/eliminating pathogens? What is the goal? |
|
Definition
-generates free radicals which are extremely reactive and free radicals also interact w/ food- radiolytic products
-goal is to max effect on target organisms/cells, limit radiolytic products |
|
|
Term
| Susceptibility to irradiation varies amongst organisms in what three ways? |
|
Definition
-vegetative bacteria most susceptible
-viruses less susceptible
-spored resistant |
|
|
Term
| Are the majority or minority of pathogens sensitive to irradiation? |
|
Definition
|
|
Term
| What is the common goal of irradiation? |
|
Definition
|
|
Term
| What are the benefits of irradiation? |
|
Definition
-increases shelf life, decreasing spoilage and waste
-decreases need to can cure, or otherwise preserve foods |
|
|
Term
| True or False: Irradiating food eliminates the need for standard measures of hygiene. |
|
Definition
-FALSE, does NOT eliminate the need for standard measures of hygiene BEFORE or AFTER irradiation
-does not eliminate organoleptic characteristics associated with spoilage
-typical doses do not sterilize |
|
|
Term
| Are there any special preparations for pasteurization of eggs? What is its goal? |
|
Definition
-controlled time-temp submersion in water but can be done in-shell
-eliminates Salmonella |
|
|
