Lecture 7: Food Safety Intro (Exam 2) Flashcards
What is food safety
The science of protecting our food supply from contamination by disease-causing bacteria, viruses, chemicals, & other threats to health
What are the four major trends creating food safety challenges
- A substantial & increasing portion of the US food supply is imported
- Consumers are eating more raw & min processed foods
- Increased @ risk populations
- Consolidation of the industry leading to amplification of food risks
How many agencies did the president assign to safeguard the food supply
~12
Who coordinates food recalls
- FDA
- USDA
- DHS
*CDC - The states
What are the components of the food safety triad
- Food supply chain
- Consumer
- Regulator
What did thomas malthus determine (the Malthusian growth potential)
- The population when unchecked increases @ a geometrical ratio
- Subsistence increases only in an arithmetical ratio
- A slight acquaintance w/ # will show the immensity of the first power in comparison w/ the second
- Humans are producing @ such a fast rate that we will eventually run out of food and die
What are the poor assumptions mad be Malthus
- he didn’t foresee to what degree technology would increase food prod
- He assumed humans have no control over their repro behavior
- He equated famine w/ a lack of food rather than an unequal distribution of ava food
What are the growth req of microorganisms
- Food - some source of E
- Acidity - best growth btw/ 4.6 & 7.5
- Temperature - the danger zone is 40 to 140 degrees F
- Time - 4 hours is considered max
- Oxygen - req by most pathogens
- Moisture - safer foods have a aw < 0.85
(FATTOM)
T/F: Nearly all foods are processed to some degree
True
What are examples of min processed
- Washed
- Peeled
- Sliced
- Juiced
- Frozen
- Dried
- Fermented
- Pasteurized
Examples of highly processed
- Baked
- Fried
- Smoked
- Toasted
- Puffed
- Shredded
- Flavored
- Colored
- Fortified (vitamins)
Why are foods processed
- Preservation
- Food safety
- Variety
- Convenience
- Nutritional enhancement
- Increase marketability
- Organoleptic properties
What are the method s of food preservation intended to accomplish
- Reduce existing pathogen load
- Render food envi inhospitable to microorganisms by ensuring one of the growth req doesn’t occur
- Provide a physical barrier to contamination/inoculation
Define food preservation
The process of treating & handling food to stop or greatly slow down spoilage in order to prevent foodborne illness & extend its shelf life
What are common food preservation methods
Describe refrigeration/freezing
- The most common preservation method
- Slows microbial growth & enzymatic action
- Fosters longer life for transportation & storage
- Storage of strategic food stocks for many nations
What is Irradiation
- Cold pasteurization
- Exposure to low dose ionizing radiation (cobalt 60 or CS137
- Kills nearly all surface pathogens (may even achieve sterilization)
- Food does not become radioactive & remains wholesome
- Endorsed by WHO & FAO
- Approved by the FDA
- Not suitable for dairy products & some fruits
- Since 1986 all irradiated food must display the radura
- Ex - wheat, potatoes, flour, & spices
Describe freeze-drying
- Combo of freezing & lowering ambient pressure which causes free water to sublimate (product typically has 1 to 4% water content)
- Causes less damage than other drying methods
- Also used for drugs (like vax)
- Does not cause shrinkage but does reduce weight
How does pickling preserves food
Preserves food in an edible antimicrobial liquid (lowers water activity & pH)
Describe chemical pickling
- Salt brine, vinegar, alcohol, & vegetable oil
- Used in food like cucumbers, peppers, corned beef, herring, eggs, & olives
Describe fermentation pickling
- The food itself produces the preservation agent
- Facilitated by Lactobacillus organims
- Ex - sauerkraut & Kimchi
Elaborate on fermentation
- One of the oldest preservation tech
- Beneficial microorganisms complete w/ pathogens
- Converts starch (sugars) to alcohol which lowers the pH (doesn’t primarily reduce water ava)
- Produces vitamins (Vit)
- Ex - beer, sour cream, kefir, kimchi, & yogurt
What is pulsed electric field electroporation
- Treating food w/ brief pulses of strong electric field
- Cell membrane pores are enlarged (killing cells)
- Most common for fruit juices
What is biopreservation
- The use of natural or controlled microflora to preserve food & extend its shelf life (good microorganisms compete w/ pathogens)
- Lactobacillus is most commonly used (produces natural preservatives like lactic acid, acetic acid, & nisin)
- Ex - veggies, cereals, & meats
- Most have broad spectrum action but some can specifically target certain pathogens