Food Safety and Spoilage Quiz

Foodborne Illness

• Foodborne illnesses are caused by a variety of factors including good, bad, and ugly aspects.
• Good factors are essential in food production, improving taste and texture.
• Bad factors are associated with infections (live organisms) and intoxications (bacterial toxins).
• Ugly factors cause spoilage with undesirable changes.
• Food storage depends on factors like whether the food is raw, cooked, or processed, and the type of food (meat, fish/seafood, fresh produce, dairy, eggs & egg products).

European Egg Handling

• British supermarkets don't refrigerate eggs.
• In North America, graded eggs are washed and sanitized before sale to reduce salmonella risk.
• In the UK, Grade A hen eggs are not washed to avoid transferring bacteria from outside to inside the egg.

Factors Needed for Bacterial Growth (FAT TOM)

• Food (high protein)
• Acidity (pH 4.6-7.0)
• Temperature (4-60°C)
• Time (reproduce every 20 minutes)
• Oxygen (presence or absence)
• Moisture (a_w > 0.85)

Food Spoilage

• Defined as damage or injury to food rendering it unsuitable for human consumption.
• It can be caused by microorganisms (bacteria, yeasts, molds), enzyme activity, or chemical reactions.
• Contaminants like pesticides, heavy metals, etc., also contribute to food spoilage.

Causes of Food Spoilage

• Microbial Growth: Bacteria, yeasts, and molds produce enzymes that decompose various food constituents. Enzymes found naturally in plant and animal tissues begin the decomposition process after death.
• Chemical Reactions: These are reactions not catalyzed by enzymes (e.g., oxidation of fat).

Vermin

• Vermin includes insects like weevils, ants, rats, and cockroaches.
• Their presence affects aesthetics.
• They can transmit pathogenic agents and consume food.
• Physical changes due to freezing, burning, or drying can also cause food spoilage.

Microbial Growth & Food Spoilage

• Food spoilage from microbes alters food visibly or less visibly, making it unacceptable for consumption.

• The process of spoilage involves a predictable succession of microbes.

• Different foods undergo various spoilage processes with the production of toxins; algal toxins can contaminate shellfish; and botulism toxins are a concern.

• Approximately one-third of manufactured foods are lost due to spoilage.

• Microbial content in foods is evaluated both qualitatively (type) and quantitatively (number).

• Raw milk sours at a microbial count between 10³ and 10⁶.

• Vacuum-packed meats emit an off-odor at a count between 10⁶ and 10⁷

• Aerobically-stored meats and vegetables release an odor at between 10⁷ and 10⁸.

• Most foods in aerobic storage show slime at approximately 10⁸-10⁹ bacteria.

• Structural change and decomposition can reach a microbial count of greater than 10⁹ bacteria.

Temperature Effect on Bacterial Multiplication

• Bacterial growth is affected by temperature.
• Generally, longer lag phases are desirable as this allows for better control of the log phase, which has less controllability over growth and is important for safety.

Minimum Growth Temperatures (of Foodborne Bacteria)

• Clostridium perfringens: 15°C
• Bacillus cereus: 10°C
• Salmonella: 4°C
• Enterotoxigenic E. coli: 4°C
• Staphylococcus aureus: 4°C
• Vibrio: 4°C
• Clostridium botulinum: 3°C
• Listeria: 1°C
• Yersinia enterocolitica: 0°C

Examples of Foodborne Bacteria

• Clostridium perfringens: Found in decaying matter, meat, and poultry. It is third most common food poisoning cause in US.
• Bacillus cereus: Typically linked with milk and cooked rice.
• Salmonella: Associated with food processing, or from feces. Consuming raw foods with eggs carries high risk. Beef, poultry, milk, and eggs are common contributors.
• Enterotoxigenic E. coli: Often from fecal contamination of food or water.
• Staphylococcus aureus: Common in foods like ham, salads, and some meats and can grow rapidly at room temperature.
• Vibrio: Linked with undercooked seafood or contaminated water (cholera).

Other Foodborne Pathogens

• Listeria: Found in raw milk, raw sprouts, and deli meats. Can thrive in refrigeration. Cooking is necessary to eliminate.
• Yersinia enterocolitica: Often found in cooler climates and associated with raw milk, undercooked meat, or contaminated water.

Microorganisms and pH

• Most Bacteria: 5.5-8.0
• Yeast: 4.0-6.5
• Molds: 4.5-6.8

Minimum and Maximum pH for Microorganism Growth

• Several examples of specific microorganisms and their minimum and maximum pH ranges for growth are provided.

pH Values of Common Food Items

• A range of values is provided for various common foods.

Water Activity Limits for Growth

• Several examples of microorganisms and their minimum water activity for growth are presented.

Water Activity of Common Food Items

• Specific examples of common food types and their water activity range are presented.

Classifying Foods: Spoilage

• Highly Perishable: Rich in nutrients, moist, and unprotected by coverings (like milk and meat).
• Semi-Perishable: Can be stored for longer periods in sealed containers, but spoil quickly once opened. Example: tomato sauce.
• Non-Perishable: Dry foods that can be stored almost indefinitely. Examples include dry pasta, uncooked rice, canned goods.

Effect of Water Activity on Heat Inactivation of Salmonella

• Data on water activity (a_w), temperature (°C), and time (min) for heat inactivation is provided.
• There are relationships/results indicated between water activity level/temperature and time required to inactivate 90% of Salmonella.

Effect of Medium (Fat Content) on Heat Inactivation of E. coli

• Information on thermal death points for various media (cream, whole milk, skim milk, whey, broth) during 10-minute heating are presented.

Thermal Death Considerations

• Microbial destruction relies on concepts about thermal death time (TDT), thermal death point (TDP), and D-values.
• TDT is time required to kill bacteria at a specific temperature.
• TDP is the lowest temperature at which a sample of microorganisms is killed in 10 minutes.
• D-value is decimal reduction time, or how much time it takes to reduce the population by 90% at a given temperature.

Internal Cooking Temperatures

• Cooking temperatures for various foods (beef/lamb, pork, poultry, ground meat, egg dishes, etc.) are detailed, in Celsius and Fahrenheit.

Heat Inactivation of Thermophilic Bacterial Spores

• Table of temperatures, pH, and time required to inactivate different spore counts are included.

Food-Borne Diseases

• Primarily categorized into foodborne infections and food intoxications.

Toxins

• Different types of toxins arising from various microorganisms, like:
• Ergotism
• Aflatoxins
• Fumonins

Exotoxins

• Produced inside bacteria and secreted, including:
• Superantigens
• Membrane-disrupting toxins
• A-B toxins Exotoxins affect the immune system, cause cell lysis, and inhibit protein synthesis.

Bacteria-Caused Foodborne Illness

• Information on the time frame and common bacteria associated with foodborne illness (intoxication or infection) is tabulated.

80/20 Rule - Pareto Diagram

• Details of a Pareto diagram examining factors contributing to foodborne outbreaks in food service establishments.
• Key data: number of outbreaks and percentage of outbreaks caused by related factors (e.g., improper cooling, inadequate cooking; contaminated ingredients, or unsafe source).

Hazard Analysis & Critical Control Points (HACCP)

• International food safety system that helps ensure the manufacture of safe food products.
• Recognized as the primary approach to enhancing food safety control throughout the food chain.
• Method developed by NASA and Pillsbury.

HACCP Principles

• Principle 1: Conduct a hazard analysis
• Principle 2: Determine critical control points (CCPs)
• Principle 3: Establish critical limits
• Principle 4: Establish monitoring procedures
• Principle 5: Establish corrective actions
• Principle 6: Establish verification procedures
• Principle 7: Establish record-keeping/documentation procedures

Critical Control Point Guidelines

• Critical steps in food preparation to prevent contamination or increase harmful microbial growth are examined.

Potentially Hazardous Foods

• A list of perishable foods (cooked or raw animal products, including meat, dairy, eggs, pies, pastries, etc.) and cooked vegetables and starches (like beans, rice, or pastas) are detailed.

Sources of Foodborne Microorganisms in Food Service Establishments

• Humans: (nose/throat, hands, fecal matter, clothing, utensils)
• Animal products: poultry, meat, eggs, fish/shellfish
• Plant products: soils, water
• Air and dust

Listeria Contamination of Processed Meat Products

• A case study on a listeria contamination outbreak of processed meat products illustrates the difficulties of eradicating pathogens in food handling and processing environments, and how contamination can result from the intersectional interaction of factors in any business environment.
• The CFIA responded to the outbreak through identification of potential factors and implementation of preventive measures regarding slicing equipment and processing conditions.

Sprouted Seeds

• Trending as a favourite food source in Canada, sprouts are popular for their nutritional value.
• These are linked to outbreaks of foodborne illness. Outbreaks associated with sprouts are well-documented.
• Contamination is likely due to initial seed contamination, and that the germination process keeps low levels of contaminants to very high levels.
• CFIA (Canada Food Inspection Agency) codes of practice focus on controlling these problems to avoid health issues arising from contaminated seed sprouts.

Records & Documentation

• The importance of clear, complete, accurate records, which includes details of seed sources, water analysis, sanitation checks, pest control, sprouting details, etc., as necessary to document all food production (and relevant) activities during manufacturing is emphasized.