Food Safety & Toxicology

What is Food Safety?

Food Safety is making a food safe to eat and free of disease causing agents such as:

Too many infectious agents Toxic chemicals Foreign objects

What is Food Quality?

Food Quality is making a food desirable to eat with regards to good taste, color, and texture; bad food quality can be judged by:

Bad color Wrong texture Smells bad

Unacceptable Foods

Poor Quality Unsafe

bad color too many bacteria

wrong texture toxic chemicals

smells bad foreign objects

Hazard

A biological, chemical or physical agent that is reasonably likely to cause illness or injury in the absence of its control

What are the Type of Food Hazards?

Biological: bacteria, viruses, parasites

Chemical: heavy metals, natural toxins, sanitizers, pesticides, antibiotics

Physical: bone, rocks, metal

A. Biological Hazards Microorganisms

Yeast Mold Bacteria Viruses Protozoa

Parasitic worms

How Do Foods Become Contaminated?

What do microorganisms need?

Food Water Proper temperature Air, no air, minimal air

Bacterial Hazards

Food infection and food intoxication Sporeforming and nonsporeforming

bacteria

Sporeforming Bacteria (Pathogens)

Clostridium botulinum Proteolytic Nonproteolytic

Clostridium perfringens Bacillus cereus

Nonsporeforming Bacteria

Brucella abortis, B. suis Campylobacter spp. Pathogenic Escherichia coli (e.g., E. coli O157:H7) Listeria monocytogenes Salmonella spp. (e.g., S. typhimurium, S. enteriditis) Shigella spp. (e.g., S. dysinteriae) Pathogenic Staphylococcus aureus (e.g., coagulase positive

S. aureus) Streptococcus pyogenes Vibrio spp. (e.g., V. cholerae, V. parahaemolyticus, V.

vulnificus,) Yersinia enterocolitica

In meat and poultry: Salmonella bacteria (poultry and eggs) Trichinella spiralis parasite (pork)

On fruits and vegetables: E. coli bacteria (apple juice) Cyclospora parasite (raspberries) Hepatitis A virus (strawberries)

Viral Hazards

Very small particles that cannot be seen with a light microscope

Do not need food, water or air to survive Do not cause spoilage Infect living cells and are species specific Reproduce inside the host cell Survive in human intestines, water or food for

months Transmission usually by fecal-oral route and

related to poor personnel hygiene

Control of Viruses

No Virus survives heating at 140°F (60oC) for 30 minutes Inactivated by boiling at 212°F

Hand sanitizers/antiseptics ineffective Important controls

No bare hand contact with ready-to-eat food Proper handwashing Not preparing food when ill

Parasites in Foods

Parasites are organisms that need a host to survive

Thousands of kinds exist worldwide, but only about 100 types are known to infect people through food contamination

Two types of concern from food or water: Parasitic worms [e.g., roundworms (nematodes),

tapeworms (cestodes), flukes (trematodes)] Protozoa

Role of fecal material in transmission of parasites

Parasitic Protozoa and Worms

Roundworms (nematodes)

Anisakis simplex Ascaris lumbricoides Pseudoterranova

dicepiens Trichinella spiralis

Tapeworms (cestodes) Diphyllobothrium latum Taenia solium, T. saginata

Flukes (trematodes)

Protozoa Cryptosporidium parvum Entamoeba histolytica Giardia lamblia

Foodborne Illness

Percentage of Foodborne Illness Attributable to Known Pathogens

Viruses67%

Protozoa3%

Bacteria30%

Mead et al., 1999

What is a Foodborne Illness?

Foodborne illnesses are caused by agents that enter the body through the ingestion of food.

Every person is at risk of foodborne illness. May be serious for very young, very old, people

with long term illness Reaction may occur in a few hours or up to several

days after exposure

Symptoms Abdominal cramps, headache, vomiting, diarrhea

(may be bloody), fever, death

What is the Impact of Foodborne

Illness?

In the US (Centres for Disease Control and Prevention) annually:

76 million cases of foodborne diseases 325,000 hospitalization 5,000 deaths

In China (1994) Salmonella Outbreak : estimated 224,000 persons

Why is Foodborne Illness increasing

in the US?

Food: Preference for “rare” meats Increase shelf life of products which allow for

bacterial growth Increase consumption of imported ready-to-eat

foods

How can you prevent Biological Hazard to Foods?

Prevention of microbes growing Holding at low temperatures (<40oF) Cooling from 140o-40oF quickly

Cooking helps to kill microbes >165oF(73o C) for poultry and eggs >155oF (68o C) for ground beef >160oF (71o C) for pork

Food from Unapproved Source

Food from Unapproved Source

Food from Unapproved Source

Unapproved Cheese Product

B. Chemical Hazards in Food

Chemical hazard: a toxic substance that is produced naturally added intentionally or un-intentionally

Naturally-occurring: Natural toxins (aflatoxins)

Added intentionally: Antibiotics, preservatives

Added non-intentionally: Cleaning agents, Pesticide residues

Intentionally Added Chemicals - Food Additives

Preservatives (e.g., nitrite and sulfiting agents)

Nutritional additives (e.g., niacin, vitamin A)

Color additives (e.g., FD&C Yellow No. 5)

Unintentionally or Incidentally Added Chemicals

Agricultural chemicals e.g., pesticides, fungicides, herbicides, fertilizers,

antibiotics and growth hormones

Toxic elements and compounds e.g., lead, zinc, arsenic, mercury, cyanide

Secondary direct and indirect e.g., lubricants, cleaning compounds, sanitizers,

paint

Mercury

Polluting with HG

MeHg kid

C. Physical Hazards In Food

• Physical hazard: a hard foreign object that can cause illness or injury Examples: plastic, bones, wood, glass, metal fragments

Poor handling procedures in the food flow

Hazard Analysis Critical Control Point (HACCP)

What is Hazard Analysis Critical Control Point (HACCP)?

The purpose of HACCP is to help ensure the production of safe food

The goal of HACCP is to prevent and/or minimize risks associated with biological, chemical, and physical hazards to acceptable levels

It is based on PREVENTION rather than detection of hazards

Pioneered in the 1960’s: first used for the space program (Pillsbury & NASA)

What are the Steps involved in HACCP?

1. Identify hazards2. Determine Critical Control Points (CCPs)3. Determine safety limits for CCPs4. Monitor CCPs5. Corrective action6. Record data7. Verify that the system is working

Good Practices in Food Chain

Good Agricultural Practices (pesticide use) Good Catering Practices (ensure food served

is safe) Good Hygiene Practices Good Manufacturing Practices Good Storage Practices Good Transport Practices

Shared responsibility

Government Consumer Industry

Food legislation/enforcement

Educated public

Good practices by producers & distributors

Consumer education

Safe food practice in home

Appropriate process & technology

Safe Eating …….