Food Pathogens and Microorganisms

Questions and Answers

What is the primary purpose of pasteurization in food processing?

To kill pathogens that can cause food-borne illnesses

How can pathogens contaminate food?

Through air, water, soil, sewage, and surfaces, as well as human skin, nasal passages, and large intestines

What is cross-contamination of food?

The transfer of pathogens from one food or surface to another

What is the result of a parasitic infection on the host organism?

The host's health suffers as the parasite obtains nourishment from the host's tissues Signup and view all the answers

What are some examples of foods that rely on microorganisms for their production?

Hard cheeses, raised breads, and alcoholic beverages Signup and view all the answers

What is the difference between beneficial and pathogenic microorganisms in food?

Beneficial microorganisms produce desirable byproducts, while pathogenic microorganisms produce harmful byproducts that spoil the food Signup and view all the answers

What are some examples of contaminants that can enter food unintentionally?

Pathogens, insect parts, residues of pesticides, and metal fragments from food processing equipment Signup and view all the answers

What happens when food is contaminated with pathogens?

The food becomes unfit for human consumption and can cause food-borne illnesses Signup and view all the answers

What type of animals can harbor harmful microbes on and in their bodies, especially in their intestinal tracts?

Animals, including cats, dogs, reptiles, cattle, and poultry Signup and view all the answers

What is a common route for transmitting harmful microbes?

Vermin, such as flies, cockroaches, mice, and rats, picking up pathogens on their feet and transferring them to food Signup and view all the answers

How do people contaminate their hands with pathogens?

When they come in contact with feces, such as while using the toilet or changing a baby's soiled diaper Signup and view all the answers

Why is it important to wash cutting boards and food preparation utensils after they come in contact with raw meat or poultry?

To prevent cross-contamination of pathogens to other foods Signup and view all the answers

What is pasteurization, and what is its purpose?

A special heating process used to destroy pathogens, commonly used by commercial food producers Signup and view all the answers

What conditions do most microbes need to survive and multiply?

Warmth, moisture, and a source of nutrients, and some also require oxygen Signup and view all the answers

What type of foods are likely to harbor pathogens?

Warm, moist, and protein-rich foods with a neutral or slightly acidic pH Signup and view all the answers

What are some examples of high-risk foods and their primary pathogens?

Beef (Salmonella species, E. coli O157:H7), Poultry (Salmonella species, Campylobacter jejuni), Eggs (Salmonella enteritidis), Fresh produce (Salmonella species, E. coli) Signup and view all the answers

Why is it important to cook foods properly?

To destroy pathogens and reduce the risk of food-borne illness Signup and view all the answers

What can happen if contaminated cutting boards and utensils are used to prepare other foods?

Cross-contamination of pathogens to other foods, increasing the risk of food-borne illness Signup and view all the answers

Study Notes

Pathogens in Food

For thousands of years, people have used microorganisms to produce foods like hard cheeses, raised breads, and alcoholic beverages.
Beneficial microorganisms secrete substances that alter food characteristics, while harmful ones spoil food and make it unfit for consumption.
Parasites like microorganisms grow and multiply in food, obtaining nourishment from the host's tissues, causing harm to the host's health.

Sources of Pathogens

Pathogens can be found in air, water, soil, sewage, and on various surfaces.
Human skin, nasal passages, and large intestines have colonies of microbes, some of which can be pathogenic.
Animals, including cats, dogs, reptiles, cattle, and poultry, can harbor harmful microbes on and in their bodies.

Common Routes for Transmitting Pathogens

Vermin like flies, cockroaches, mice, and rats can transfer pathogens to humans when they come in contact with filth and then with food.
Poor personal hygiene practices, like not washing hands after using the toilet or changing diapers, can transfer microbes to food.
Animals can also transfer pathogens to food through their feces, skin, and fur.

Cross-Contamination of Food

Improper food handling can result in food-borne illness, such as failing to wash cutting boards and utensils after contact with raw meat or poultry.
Cross-contamination can occur when contaminated boards and utensils are used to prepare other foods, transferring pathogens.

Pasteurization

Pasteurization is a special heating process used to destroy pathogens in food.
Many commercial food producers use pasteurization, such as for juices and milk in the United States.

Conditions that Favor Pathogen Survival and Multiplication

Most microbes need warmth, moisture, and a source of nutrients to survive and multiply.
High-risk foods are warm, moist, and protein-rich, with a neutral or slightly acidic pH.

High-Risk Foods

High-risk foods include meats, eggs, milk, and products made from milk, which fit the description of warm, moist, and protein-rich with a neutral or slightly acidic pH.
Table 12.1 lists high-risk foods and their primary pathogens, such as rare hamburger with Salmonella species and E. coli O157:H7.