Lecture 12- food protection and preservation Flashcards
(32 cards)
Food protection
Addresses both food safety and food defense
Food safety
Preventive measures employed to protect food from biological, chemical and physical hazards to human health
Addresses unintentional contamination
Food defense
Effort to protect food from acts of intestinal adulteration
Negative attributes for food quality
Spoilage, contamination with filth, discoloration, off-odors
Positive attributes for food quality
Origin, color, flavor, texture
Food control
Mandatory regulatory activity of enforcement by national or local authorities to provide consumer protection and ensure that all foods during production, handling, processing and distribution are safe, accurately labeled, conform to safety
Food security
Exits when all people at all times have physical and economic access to sufficient safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life
Why process foods
Preservation and food safety
Variety, convenience, nutritional enhancement, increase marketability, organoleptic properties
Concerns for highly processed foods
Added sugar, sodium, saturated/trans fat, lower in fiber, refined grains, high in calories, conducive to unhealthy food behaviors
Food preservation
The process of treating and handling food to stop or greatly slow down spoilage in order to prevent foodborne illness and extend shelf-life
Methods of food preservation are intended to accomplish one or more of the following
Reduce the exiting pathogen load, render food environment inhospitable to microorganisms, provide physical barrier to contamination
How do you make food environment inhospitable to microorganisms
Reduce water activity, alter pH, alter temperature, low oxygen content
What are the microorganism growth requirements
FATTOM
Food-energy source
Acidity- pH between 4.6-7.5 ideal for growth
Temperature- Danger zone between 40-140F
Time- four hours is average time for dangerous growth
Oxygen- required by most pathogens
Moisture- aw< 0.85 increases safety and decreases bacterial growth
What are common food preservation techniques
Refrigeration, irradiation, pasteurization, freeze-drying, salt or sugar curing, pickling, fermentation, smoking, modified atmosphere, hurdle technology
What are the 3 methods to reduce existing pathogen loads
Refrigeration, irradiation, and pasteurization
How does refrigeration/freezing preserve food
Slows microbial growth and enzymatic action, fosters longer life for transpiration and storage
How does irradiation preserve food
Aka cold pasteurization
Exposure to low dose ionizing radiation, kills nearly all surface pathogens
How does pasteurization preserve food
Technique for liquid food, kills 99% of pathogens in milk-but spoilage organisms survive
What is the shelf life for high temperature, short time pasteurized milk
60-90 days
What is the shelf life for ultra high temperature pasteurized milk
180 days
What are the 6 methods that render foods inhospitable to microbial growth
Freeze-drying, salt or sugar curing, pickling, fermentation, smoking, modified atmosphere
How does freeze drying prevent microbial growth
Low ambient pressure, reduce water activity and content, cause less damage than other drying methods
Used for vaccines
How does pickling reduce microbial growth
Preserves food in edible antimicrobial liquid- lowers water activity and pH
How does fermentation prevent microbial growth
Commensal organisms compete with pathogens, converts starch to alcohol: lowering pH, produces vitamins
