Food Preservation Flashcards
Concerns over highly processed foods
Added
• Sugar
• Sodium
• Saturated/trans fats
- Low in fiber
-Refined grains
-High in calories
- Conducive to unhealthy behaviors
2009 recall of peanut butter result in affected (7)
-Peanut butter
• Cookies
• Crackers
• Cereal
• Candy
• Ice cream
• Pet food
Food preservation definition
The process of treating and handling food to stop or greatly slow down spoilage in order to prevent foodborne illness and extend shelf-life
Food preservation methods are intended to accomplish (3)
1) Reduce the exiting pathogen load
2) Render food environment inhospitable to microorganisms
• Reduce water activity (a
• Alter PH
• Alter temperature
• Low oxygen content
3) Provide physical barrier to contamination/inoculation
Microorganism growth requirements (FATTOM)
• Food – Energy source
• Acidity – PH between 4.6 and 7.5 is ideal for growth
• Temperature – Danger zone is 40oF to 140oF
• Time – Four hours is average time for dangerous growth
• Oxygen – Required by most pathogens
• Moisture – <0.85 increases safety and decreases bacterial growth
How many people suffer from food security worldwide
820 million
How many billion tons of food are lost or wasted each year (and what proportion is this of all food produced for food consumption)
1.3 billion tons = 1/3 of all food produced for food consumption
Which 2 commodity groups experience the most losses per year
Fruits/veggies
Roots and tubers
3 methods of food preservation that reduce existing pathogen loads (RIP)
Refrigeration
Irradiation
Pasteurization
Most common food preservation method
Refrigeration/freezing
Refrigeration/freezing
-Slows microbial growth and enzymatic action
-Fosters longer life for transpiration and storage
-Storage of strategic food stocks for many nations
Irradiation/cold pasteurization
• Exposure to low-dose ionizing radiation (Co-60 or Cs-137)
• Kills nearly all surface pathogens (may even achieve sterilization)
• Food does not become radioactive and remains wholesome
• Endorsed by WHO, FAO and approved by FDA
• Not suitable for dairy products and some fruits
All irradiated food must display
Radura symbol
Is irradiation suitable for fruits and dairy products
no
Which food preservation method is ideal for liquid food
Pasteurization
Pasteurization
-Preservation technique for liquid food: originally for wine
• Kills 99.999% of pathogenic microorganisms in milk
• NOT complete sterilization; spoilage organisms survive
3 different temperature-time methods of pasteurization
• HTST: High-Temperature, Short Time - 160F for 15 seconds or 145F for 30 minutes
• UHT: Ultra High Temperature - 275F for 2 seconds
• ESL: Extended Shelf Life - Lower temperatures than UHT but adds a filtration step
Shelf life for high temperature short time vs ultra high temperature: milk pasteurization
HTST = 60-90 days
UHT = 180 days
6 methods of food preservation that render foods inhospitable to microbial growth
• Freeze-drying
• Salt or sugar curing
• Pickling
• Fermentation microbial growth
• Smoking
• Modified Atmosphere
Freeze drying
-Combination of freezing and lowering ambient pressure
•-Causes free water to sublimate, thus reducing water activity
• Product typically has a water content of 1%-4%
• Causes less damage to food stuffs than other drying methods
• Also used for pharmaceuticals such as vaccines
• Does not cause shrinkage, but does reduce weight
• Popular for hikers
Pickling
• Preserves food in edible, antimicrobial liquid
• Lowers water activity
• Lowers pH
• Salt brine, vinegar, alcohol,
vegetable oil…
• Foods such as cucumbers, peppers,
corned beef, herring, eggs, olives…
One of the oldest preservation techniques is
Fermentation
fermentation
-Beneficial microorganisms (e.g., Lactobacillus sp.) compete with pathogens
-place food in anaerobic container to allow lactobacteria to grow
• Converts starch (sugars) to alcohol: lowering pH
• Produces vitamins (primarily B vitamins)
• Foods such as beer, sour cream, kefir, kimchi, yogurt…
Salt or sugar curing
• Both result in reduced water
activity (aw)
• Additionally, osmotic pressure lyses cell membranes
• Examples: salted meat, fruit in
honey (or heavy syrup), salted anchovies…
Smoking (food preservation)
• Wood smoke deposits natural preservatives on meats and fish
• Physically dries the surface of foods
• Can be combined with canning
Modified atmosphere
• Storing or packaging foods that spoil easily or age quickly
• Reduced oxygen; replaces with carbon dioxide or nitrogen
• Slows aging and prevents insect infestation
• Eastern WA has MA space for >100 million boxes of
apples
• MA grains can be stored for 4-5 years
Hurdle technology
• Controlling (or eliminating) foodborne pathogens by the application of MORE THAN ONE APPROACH= Giving the pathogens more ‘hurdles’ to overcome
-Approaches are specifically selected to preserve organoleptic qualities
-high temperature during processing
Low temperature during storage
-increasing acidity
-lowering water activity
-adding antimicrobials/antioxidants
Who developed astronaut food
Pillsbury and us army
HACCP basics
-Science-based system of food safety
• HACCP prevents rather than detects
• Focuses on health hazards; NOT product quality
• Made mandatory in both U.S. and EU
7 steps of HACCP (general)
1) Assess Potential Hazards
2) Determine Critical Control Points
3) Establish Requirements for each CCP
4) Establish procedure to Monitor each CCP
5) Establish Corrective action if deviation
6) Establish Record keeping procedures
7) Establish procedure to Monitor effectiveness
