lecture 7: food safety intro Flashcards
the science of protecting our food supply from contamination by disease causing bacteria, viruses, chemicals and other threats to health
food safety
four major traits creating food safety challenges
1) increasing portion of the U.S. food supply is imported
2) Consumers are eating more raw and minimally processed foods
3) Increased at risk populations
4) Consolidation of industry leading to amplification of food
risks
food recalls are coordinated by
FDA, USDA, DHS, CDC, states
what is in the food safety triad
consumer
food supply chain
regulator
principle of population : Thomas Malthus
Population, when unchecked, increases at a
geometrical ratio. Subsistence increases
only in an arithmetical ratio. A slight
acquaintance with numbers will show the
immensity of the first power in comparison
with the second.
what is this graph showing
malthusian growth potential of substance VS population
poor assumptions by Thomas Malthus
- the degree in which technology would increase food production
- assumed humans have no control over their reproductive behavior
- equated famine with a lack of food rather than an unequal distribution of available food
microorganism growth requirements: FATHOM
- Food – Some source of energy
- Acidity – Best growth between 4.6 and 7.5
- Temperature – Danger zone is 40oF to 140oF
- Time – Fours hours is considered maximum
- Oxygen – Required by most pathogens
- Moisture – Safer foods have < 0.85
how can foods be minimally processed
- Washed
- Peeled
- Sliced
- Juiced
- Frozen
- Dried
- Fermented
- Pasteurized
how can foods be 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
highly processed foods are not inherently unhealthy, but they have
- Added sugar
- Sodium
- Saturated/trans fats
- Low in fiber
- Refined grains
what is the goal with these :
* Reduce existing pathogen load
* Render food environment inhospitable to microorganisms
* Reduce water activity (aw)
* Alter pH
* Alter temperature
* Lower oxygen content
* Provide physical barrier to contamination/inoculation
food preservation
define food preservation
The process of treating and handling food to stop or
greatly slow down spoilage in order to prevent
foodborne illness and extend its shelf-life
Refrigeration/Freezing
- Slows microbial growth and enzymatic action
- Fosters longer life for transportation and storage
- Most common
methods for food preservation (say any 5)
- Refrigeration and freezing
- Canning and bottling
- Irradiation
- Dehydrating/drying
- Freeze-drying
- Salt or sugar curing
- Pickling
- Pasteurizing
- Fermentation
- Smoking
- Vacuum packaging
- Food additives
- Burying
- Modified atmosphere
- Pulsed electric field electroporation
- Pressurization
- Biopreservation
- ‘Hurdle’ technology
- Not suitable for dairy products and some fruits
- Food does not become radioactive and remains wholesome
- Exposure to low-dose ionizing radiation (Co-60 or Cs-137)
- Kills nearly all surface pathogens…may even achieve sterilization
irradiation
cold pasteurization
describe Freeze-drying
Combination of freezing and lowering ambient pressure
* Causes less damage than other drying methods
* Also used for pharmaceuticals such as vaccines
* Does not cause shrinkage, but does reduce weight
- Preserves food in an edible, antimicrobial liquid
- Chemical pickling
* Salt brine, vinegar, alcohol, vegetable oil - Fermentation pickling
* Facilitated by Lactobacillus organisms
* Foods such as sauerkraut, kimchi
pickling
fermentation is one of the __________. it converts _________ and Lowers PH. it produces vitamins.
oldest preservation techniques
starch (sugars) to alcohol
- Treating food with brief pulses of strong electric field
- Cell membrane pores are enlarged, killing cells
- Most common for fruit juices
pulsed electric field electroporation
Biopreservation
-The use of natural or controlled microflora to preserve food and extend its shelf life
-Lactobacillus is a common
-are broad-spectrum in action
which preservation technique will result in lower water activity.
Salt or sugar curing
Pasteurization
- Preservation technique for liquid food; originally for wine
- Kills 99.999% of microorganisms in milk
- High-temperature, short time (HTST)
- Ultra high temperature (UHT)
- Extended shelf life (ESL)
