Exam 5 Food Sci Nutrition

_______ is the study of the physiological genetics, growth, characteristics, survival, and behavior of microbes

Microbiology

Microbiologists focus on WHAT?

They focus on microbes that grow and survive in foods

Within the background of microbiology, ______ are responsible for almost all of foodborne illness and cause most food spoilage

Microbes

Within the background of microbiology, ________ cause diseases and lead to death

Pathogens

True or false: There are beneficial microbes that may be ingested to fight off harmful microbes?

True

What foods contain beneficial microbes?

Fermented Foods that consist of:

• Yogurt

• Bread

• Wine

• Beer

• Sausage

What 3 main types of microorganisms in the foods we eat every day?

1. Bacteria

2. Mold

3. Yeasts

Why can’t we see microorganisms in our foods?

Because they are:

• Usually TOO small to see with the naked eye

• Don’t expect them to be in our foods

Many types of microorganisms are classified as?

Genus/Species

Morphology

Chemical Reactions

Nutrient Requirements

Metabolic Products

What are some different categories of Microbes?

What 2 microbes are inside fungi?

• Bacteria

• Fungi

  • Yeasts

  • Molds

• Protozoa (parasites)

• Viruses

The usage of bacteria involves cells being unicellular ________ and found almost everywhere

Prokaryotes

Bacteria is a category of microbes that involves bacterial classifications that include _________ _____, ___, and ____ ____ (review this slide)

Gram Stain Reactions: (+ or -)

Shape: coccus, bacillus, or spirillum

Spore-Farming: the ability to say yes or no?

Fungi is a category of microbes that involves molds that are ________ or _______

Multicellular Unicellular

______ are within the microbe fungi that have a central nucleus and grow through mycelium and produces toxins, antibodies, and enzymes

Eukaryotes

______ are unicellular fungi microbes that are spherical or oval shaped and grow faster in molds

Yeast Cells

________ are single-celled eukaryotes that are a category of microbes that are classified by morphology, locomotion, senses, and overall life cycle and require a HOST to complete their life cycle

Protozoa

True or False: Protozoa grows in foods

FALSE they need a host to grow instead

Examples of Protozoa include:

Giardia

Cyclopia

Toxoplasma

Entamoeba

How does Protozoa travel (sources)?

Intestinal Tract

Water Transport

__________ are another form of microbes that are all parasitic and are generally host-specific, where most of the food ______ will inject their own RNA Replication into the HOST, making it their own (Bacteriophages)

Viruses Viruses

What types of viruses are transmitted through foods?

Hepatitis A

and

Norwalk viruses

Microbe Reproduction is indicated by ____ ______ that goes under optimum conditions that may take as little as 30 minutes for it to spread

Cell division

What ways to spot the spread of microbial reproduction?

• Under different (or changing) conditions, cells will take longer and divide, causing slower growth of microbes

• Examples of these include (growth curves and growth patterns)

What 4 factors of a growth curve can affect the microreproduction?

Lag: no or slow growth, getting used to the environment

• control is very important

Log: Rapid Growth

Stationary: as many cells are dying a are being created

Death: Water Products are toxin, food is gone

What are the sources of microorganism (where can they come from)?

• Water soil air

• Raw food, handling, and processing

• Introduced at processing (most likely)

What are the 3 roles/rules of microbes?

1. They are USEFUL, because they bring up new ideas and studies/and opportunities

2. Spoil foods

3. Pathogenetic

________ _____ refers to the environmental characteristic that surrounds a food product that can get contaminated through temperature, relative humidity, and gaseous environment

Extrinsic Foods

______ ____ refer to the FOOD composition and have characteristics that influence microbial growth WITHIN the FOOD via water activity, pH, Nutrients, and Moisture contenct

Intrinsic Foods

What are some ways that we can control the growth of microorganisms by people regulating and keeping track of:

• FATTOM

Food

Acidity

Temp

Time

Oxygen

Moisture

Within various kinds of food, _____ ______ vary with the type of organisms but most foods provide high nutrient availability for microorganisms with some limitations that may be required for sugars

Nutrient Requirements

Why do some organisms require that other microbes break down components?

Certain enzymes cant and can break down chemical components so other organism are needed

WIthin the acidity and alkalinity, the ___ in which live in a particular range labeled as MIN MAX and OPTIMUM

pH

Where is the optimum for meat at?

Neutrality

3 types of minimums include

• Bacteria: ___

• Yeasts: ___

• Molds: ___

Bacteria: 4.5

Yeasts: 3.0

Molds: 2.0

PH and Acid is in different scales: ________ has a natural pH of 4.6 or less (<4.6)

Acid Foods

Low acid foods = ____ pH

High pH

PH and Acid is in different scales: _______ ___ are low acid foods which are added to and have a pH of 4.6 or less (<4.6) and a water activity of 0.85 or

Acidified Foods

PH and Acid is in different scales: ___ ___ ___ have a pH thats greater than 4.6 (>4.6) and a water activity of 0.85 or more)

High Acid= ____ __ pH

Low pH

Considering temp and time factors there is always ___ ____ ____ that needs to be considered

Max Min and Optimum

Psychrophiles have a

• Min ___

• Opt ____

• F ____

Min: -10

Opt: 10-15

F: 55 (coldest)

Psychrotrophs have a

• Min: ___

• Opt: ___

• F: ___

Min: -5

Opt: 20-30

F: 77

Mesophiles have a:

• Min: ___

• Opt: ___

• F: ___

Min: 5

Opt: 30-37

F: 95

Why are mesophiles the most exposed to microbes?

Since it has a middle temperature of 95 degrees F it is considered in the danger zone and can be exposed to microbes easily

Thermotrophs have a:

• Min: ___

• Opt: ___

• F: ___

Min: 10

Opt: 42-46

F: 112

Thermophiles have a

• Min: ___

• Opt: ___

F: ___

Min: 25

Opt: 50-80

F: 150 (hotest)

Danger zone Temperature range is _____ to ___

40-140

• easy for microbes to grow

• don’t let sit in a long period of time

The role of O2 is huge in foods for it does What?

• Necessary for microbes to grow

• the amount of O2 applied and exposed to matters

_______ is an microbe that requires O2

Aerobes

________ is a microbe that utilizes traces of O2

Microaerophilic

_______ is a microbe that cannot tolerate O2

Anaerobes

______ _____ relates to the H2O availability in foods

Water Activity

Why does bacteria require H2O activity?

Every bacteria form needs H2O to grow, and the more H2O involved, the easier it it for microbe growth

How much H2O is needed for bacteria microbes to grow?

Very high-water activity, About >90%

How much H2O is needed for yeasts microbes to grow?

Moderate High Water activity, About >0.80%

How much H20 is needed for mold microbes to grow?

Lower Water Activity, about >0.70

______ are chemical compounds that slow microbial growth that consist of 3 types

Inhibitors

________ is a type of inhibitors that is directly added to the food

Preservatives

_________ is a type of inhibitor that only tolerates salt

_________ is a type of inhibitor that sugar

Halophilic

Osmophilia

_______ is a type of inhibitor that is chemical produced by bacteria that inhibits others

Bacteriocins

______ is strategy were a series of nonlethal level of controls are implemented

hurdle Concept

___________ is a biological process by which microorganisms form chemical reactions that leads to food preservation

Fermentation

What is the most common producing bacteria organism used in foods?

Lactic Acid

Homofermentors produce how many compounds?

Heterofermentors produce how many compounds?

Produces single compounds

Produces more than one compounds

_______ _____ are used to initiate most foods tat ferments

Starter Culture

Different Beneficial Microorganisms in foods include

• Lactococcus

• Lactobacillus

• Padiococcus

• Saccharomyces

• Molds: Aspergillus (soy sauce)

  • Penicillium (cheese)

Lactococcus: cheese

Lactobacillus: Yogurt

Pediococcus: Sausage

Saccharomyces: Wine and bread

Molds and Lactococcus bot have cheese involved

how in the world does yogurt get made?

Many processes consist of

• pasteurization/homogenization

• heat 190°F to denature proteins in milk

• Cooled at 104°F

• Starter Culture

• Incubate at 109-122 (p 3.7-4.3) ten fill into containers

True or False: All meat must be salt-tolerant and produce lactic acid

TRUE All meat must be salt tolerant and produce lactic acid

Fermentation of fruits and vegetables contains _ different types if cultures organism which include

3 of them, which include:

• leconotide mesenteritis

• Lactobacillus brevis

• Padiococcus cerevisiae

What does cider production rely on?

It relies on the yeast for the fermentation that repdices O2 and alcohol

Within spoilage organisms, there are common spoilage bacteria genera that include