Food Science Test 2

Demonstrated that air was not the cause of spoilage

Louis Pasteur

Developed the first microscope

Anton Van Leeuwenhoek

Father of canning

Nicholas Appert

Received the Nobel Prize in 1905 for demonstrating that a particular organism is responsible for a disease and that it can be transmitted from one animal to another

Robert Koch

A Pathogen does what?

Makes you sick

Bacterial ________________ is responsible for the slimy "texture" of spoiled fish or chicken.

Capsule

Viruses replicate in food and living cells.

False

Microorganisms are capable of producing which of the following.

Acids, CO2, Toxins, Alcohol

An acid produced during spoilage of milk causes

Protein Denaturation

Assume that a given food had a population of 150,000 microorganisms per ml. How many colonies would form on plate #4 above?

150

Assume that a given food had a population of 150,000 microorganisms per ml. How many colonies would form on plate #5 above?

15

Assume that a given food had a population of 150,000 microorganisms per ml. Which plate should be counted to determine the # in the original sample?

Plate 4

Under optimal conditions, which of the following grows fastest?

Bacteria

A bacteria with an initial population of 3 colonies, has a generation time of 20 minutes. How many bacteria will there be after 2 hours under optimum conditions for growth?

192

Which of the following are FAT-TOM factors that affect the growth of microorganisms?

Moisture, Texture, Oxygen, Time

Which of the following usually requires the highest pH (lowest acid level) for growth?

Bacteria

Which of the following terms describes a heat-loving organism?

Thermophile

The microorganism responsible for milk spoilage (while it is kept in the refrigerator) is

Psychrotroph

The term facultative anaerobic means an organism will grow under what type of conditions?

In the presence or absence of oxygen

Most spoilage bacteria require an Aw that is greater than _____?

0.91

A natural substance found in cranberries that inhibits the growth of yeasts and molds would be which of the following?

Sodium Benzoate

Which of the following inhibitory substances is added to bread to control the growth of mold?

Calcium Propionate

Under optimal conditions, which of the following grows fastest?

Bacteria

Which of the following is true of a bacterial endospore?

Are difficult to kill even with heat, Are very resistant structures, Is a survival mechanism of the organism

At the stationary phase, organisms are doing what?

Running out of food, space, etc.

Propionate inhibits ______________ while benzoate inhibits _____________.

Mold; yeast and mold

Plate count was used to determine the microbial load in 1 ml of milk. 35 colonies were counted on the 1:1000 dilution plate. How many CFU (Colony Forming Units) per ml were in the original sample of milk?

35,000

A bacteria with an initial population of 3 colonies, has a generation time of 20 min. How many bacteria will there be after 2 hours under optimum conditions for growth?

192

Patulin is a carcinogen produced by molds growing on corn.

False

In a restaurant food-prep area, mold is discovered on a 5 lb block of cheddar cheese. This should be carefully trimmed off before serving to customers.

False

St. Anthonys Fire, an epidemic during the Middle Ages, was the result of consuming moldy rye.

True

This is a potent liver carcinogen

Aflatoxin

There is a hypothesis that the strange behavior of the residents of Salem Massachusetts was the result of consuming mold-infested rye. What is the compound produced by the mold that could account for bizarre behaviors?

Lysergic acid

A highly resistant structure produced by only certain bacteria.

Endospore

Clostridium botulinum is a sporeforming bacterium that will not germinate at a pH...

<4.6

An emetic, such as the toxin produced by Bacillus cereus, causes

Vomiting

_________ causes a low body temperature and produces a heat-stable toxin

Staphylococcus aureus

__________ is an anaerobic bacterium that is heat-labile/sensitive and difficult to diagnose.

Clostridium botulinum

Which of the following is a medical use for Clostridium botulinum toxin

Clenching of jaw muscle, wrinkle remover

Honey is not safe for kids under 1 year of age, because Clostridium botulinum spores will be able to germinate, grow, and produce toxin in their intestinal track.

True

____________ is a facultative anaerobe that produces two different types of toxins.

Bacillus cereus

A foodborne intoxication is caused by the ________________, while a foodborne infection is caused by the presence of ________________.

Toxin; bacteria

What bacterium causes the most cases of SERIOUS foodborne illness?

Salmonella

What bacterium causes the MOST CASES of foodborne ILLNESS?

Campylobacter

This organism is found inside the egg of a chicken.

Salmonella enteriditis

Listeria is associated with

Lunch meat, stillbirths, unpasteurized milk

What pathogen(s) is/are associated with poultry?

Salmonella, Campylobacter

Consuming raw oysters will put you at risk of foodborne illness caused by _____________________.

Vibro vulnificus

Which of the following microorganism(s) is/are psychrotrophs (able to grow at low/refrigerator temperatures?

Listeria monocytogenes, Yersinia enterocolitica

A toxin-mediated infection is caused by

The toxin produced by the bacteria once it's growing inside of you

Which of the following causes toxin-mediated infections?

E. coli, Shigella

E. coli causes which of the following unique symtoms?

Bloody diarrhea, Hemorrhagic Colitis, HUS

__________ causes more gastrointestinal disease than any other organism and has been associated with outbreaks on cruise ships.

Norovirus

This organism is frequently involved in outbreaks in daycare centers.

Shigella

All E.coli strains are pathogenic, meaning that all E.coli strains are a human threat.

False

Which virus causes the MOST CASES of foodborne DISEASE?

Norovirus

Hepatitis A is the only hepatitis transmitted from food. It targets the

Liver

All of the viruses discussed in class are fecally transmitted.

True

Which of the following does NOT constitute a food as "potentially hazardous"?

High in lipids

Which of the following DOES constitute a food as "potentially hazardous"?

Low acid, High in protein, High Aw

Foods should be cooked at least to the minimum recommended temperatures. Those temperatures are...

Poultry: 165 F; Ground Meats: 155 F ; Other potentially hazardous foods: 145 F

The #1 parasite associated with humans is __________.

Giardia

This parasite has been associated with imported raspberries.

Cyclospora

__________ is associated with cats and can affect the unborn.

Toxoplasma

Pork is associated with __________.

Trichinella

Cause of a major waterborne outbreak in Milwaukee

Cryptosporidium

Tapeworm

Taenia

Reproduce by producing proglottids

Taenia

Associated with Sushi

Anisakis

Cats are a reservoir

Toxoplasma gondii

Single cell organism

Protozoa

Fermentation is a process of converting raw foods into fermented foods by using

Microorganisms

Which of the following is a good way to preserve meat?

Temperature (hot or cold), Salting, Drying, Smoking, Irradiation, Fermentation

All of the following are examples of fermented foods:

Cheese, beer, sausages, sauerkraut, bread

The types of microorganisms that are used in fermented food production include:

Bacteria, Yeasts, Molds

What is a probiotic?

Live bacteria that are good for your health, especially your digestive system

The main byproduct (waste) of fermented cheese manufacturing is

Whey

Which of the following are ways that microorganisms can be introduced into foods to initiate fermentation?

Add a culture containing desired organisms, Rely on indigenous organisms, Use of backslopping during production

How is the yeast removed from champagne after production is complete?

Frozen in a bath and pulled out through the top of the bottle

What is the function of the starter culture in sausage fermentation?

LABS produce lactic acid and lower pH, Produce flavor, Out-compete pathogenic microorganisms

Non-lactic acid bacteria can generally be inhibited and good bacteria can be selected for in fermented products by:

Adding salt, Creating anaerobic conditions (anaerobiosis), Lowering the pH

What antibody is associated with a true food allergy?

IgE

Anaphylaxis is a severe type of allergic reaction that involves two or more body systems (e.g., hives and difficulty breathing).

True

The "Big 8" are responsible for 90% of IgE-mediated food allergies and include all of the following EXCEPT:

Corn

__________ occurs when an individual lacks the enzymes necessary to utilize a specific food component. A classic example is lactose intolerance.

Metabolic food disorder

Which allergen does not cause the most food allergies in infants?

Crustacean shellfish

This food is responsible for most food allergy related fatalities.

Peanuts

This should be administered as soon as there is indication an individual is experiencing a severe allergic reaction.

Epinephrine

How does bacteria reproduce?

Binary Fission

What are the general characteristics of a virus?

1. don't replicate in food (not spoilage organisms)

2. are pathogens

3. only replicate in living cells

Spoils food, ellipsoidal shape, larger than bacteria, reproduce by budding

Characteristics of yeast

Grow by a network of filaments (mycelia), as these filaments get bigger, they form a sproangium that sends thousands of spores into the air

Process of growing for molds

Why is FAT-TOM important and what does it stand for?

Helps with controlling the growth of microorganisms in foods. Food Acid Temperature Time Oxygen Moisture

Between molds, yeasts, and bacteria, which grows at the lowest pH?

Molds

love heat

thermophiles

medium temp... room temp... body temp. Most pathogens are these

mesophiles

love cold

psychrophiles

tolerates cold, but grows better at room temperature (milk in fridge)

psychrotrophs

needs oxygen to survive

aerobic

can't grow in presence of oxygen (canned foods)

anaerobic