FMLec | M1: History & Developments

Historical developments in Food Microbiology can be divided into:

• Observation of microbes in food

• Fermentation

• Food preservation

• Food spoilage

• Food poisoning

_ is an era that preceded the establishment of Bacteriology or Microbiology as a science; microbe-food association

Prescientific era

2 periods in Prescientific Era significant in Food Microbiology

• Food-gathering period

  • Carnivorous

  • Introduction of plant foods and cooking

• Food-producing period (higher food supply)

  • Food spoilage

  • Food poisoning

  • Disease transmission by food

Period characterized by carnivorous diets and introduction to plant foods and cooking

Food-gathering period

First person to appreciate and understand the presence and role of microorganisms in food

Louis Pasteur

Enumerate 5 examples of fermented food products in the ancient civilizations

be chee wi fe bre

• Beer = Babylonia, Sumeria, Egypt

• Cheese = Egypt

• Wine and vinegar = Assyria

• Fermented sausage = Ancient Babylonia, China

• Bread = Rome

Who identified that souring of milk is due to lactic acid fermentation?

Joseph Lister

In what year did Metchnikoff & co-workers isolate and name one of the yogurt bacteria, Lactobacillus delbrueckii subsp. bulgaricus

1907

Killing all viable microorganisms, including endospores

sterilization

3 ancient methods of food preservations

sps

• Salting = Sumerians, Jews, Chinese, Greeks sjcg

• Pickling and snow = Romans

  • Snow is problematic bc it can contain potentially harmful microorganisms and temperature is not controlled/consistent

• Smoking

The role of microorganisms in food spoilage was first observed by the monk _, who loved examining decaying bodies, meat, milk, and other substances dmmo

A. Kircher

T/F: Dry heat is better than moist heat

FALSE

Moist heat is better because it’s more penetrative than dry heat and thus less time-consuming

Who coined the term “osmophiles”? When?

Richter, 1912

Who was the first to study thermophiles? When?

Miquel, 1888

Period characterized by food spoilage, food poisoning, and disease transmission by food

Food-producing period

Ancient method of food preservation done by Romans

Pickling and snow

The role of microorganisms in food spoilage was first observed by the monk A. Kircher, who loved examining _

decaying bodies, meat, milk, and other substances dmmo

Describe the history of the discovery of spoilage microorganisms chronologically

fmsr

• 1887 = Foster was the first to demonstrate the ability of pure culture of bacteria to grow at 0 C (psychrotolerant)

• 1888 = Miquel was the first to study thermophiles

• 1902 = Schmidt-Nielsen first used the term “psychrophiles”

• 1912 = Richter coined the term “osmophiles” (very high concentrations of sugar/osmotic pressure)

Microorganisms that can grow on syrup, honey, very high sugar conc.

Osmophiles

Describe the history of observation of foodborne pathogens

• 1820 = Sausage poisoning (probably botulism)

• 1894 = First association of staphylococci with food poisoning (T. denys)

• 1926 = First report of streptococci food poisoning (Linden, Turner, Thom)

• 1937 = Recognition of paralytic shellfish poisoning

• 1960 = Aflatoxin of Aspergillus flavus

• 1965 = Recognition of foodborne giardiasis (caused by protest)

• 1986 = First diagnosis of Bovine Spongiform Encephalopathy (BSE) in cattle in United Kingdom

What type of microbe cause Bovine Spongiform Encephalopathy (BSE)?

Prions

BSE

• in cows is called _;

• while in sheep, it’s _;

• in humans, it’s _

• Mad cow disease

• Scrapie

• Creutzfeldt-Jakob disease (CJD)

Year in history of observation of foodborne pathogens

• Recognition of foodborne giardiasis

1965

Name of yogurt bacteria isolated by Metchnikoff & co-workers in 1907

Lactobacillus delbrueckii subsp. bulgaricus

Discovery of Pasteur that souring of milk was due to microorganisms happened on which year?

1837

_ discovered that souring of milk is due to microorganisms (1837)

Louis Pasteur

Salting is an ancient method of food preservation done by _

Sumerians, Jews, Chinese, Greeks sjcg

Developments in heat preservation methods

saud

• Steam sterilization attempted in 1843

• Autoclaving of food in 1853

• Use of heat in commercial setting in 1867-1868

• D value concept came into general use in 1950

What year did the use of Pasteurization start?

1860

Cheese is fermented food that came from which ancient civilization

Egypt

Louis Pasteur discovered the aerobic and anaerobic growth of yeast on which year?

1861

Who isolated and named the yogurt bacteria Lactobacillus delbrueckii subsp. bulgaricus in 1907?

Metchnikoff & co-workers

_ is a heat treatment process that eliminates unwanted/undesirable microorganisms and keeps these to safe/acceptable levels

Pasteurization

Fermented sausage is fermented food that came from which ancient civilization

Ancient Babylonia, China

Explain the early observations on the effect of heat on microorganisms

• Spallanzani’s experiment

  • Had 2 setups and in each of which, he boiled the broth in the flask to kill any existing microorganisms

  • The only difference between 2 setups is that he sealed the cap of one flask, while he left the other open

  • Results showed that the sealed flask developed no microbial growth, while open flask had microbial growth

  • This proved that microorganisms don’t spontaneously arise from the broth but comes from the air

  • Critics, however, did not accept this bc sealing the flask meant removing the “vital force” in the air that they believe to be necessary for spontaneous generation to occur

• Pasteur’s swan-necked flask experiment

  • Had the same 2 setups with boiled broth inside, except that he used swan-necked flasks to still allow air to enter but traps dust and microorganisms, preventing these from reaching the broth

  • Results showed that both setups had no microbial growth despite air exposure

  • However, when he broke the neck and left flask in the open, days after, microbial growth was observed proving that microorganisms don’t spontaneously arise from the broth but actually come from the environment

  • Or when he tipped the flask, microorganism-laden dust contacted sterile liquid → liquid putrefaction

Bread is fermented food that came from which ancient civilization

Rome

Wine & vinegar is fermented food that came from which ancient civilization

Assyria

Other methods of preservation

orn

• 1882 = Ozone

• 1943 = Radiation

• 1954 = Nisin (antibiotic)

Beer is fermented food that came from which ancient civilization

Babylonia, Sumeria, Egypt

Who first used the term “psychrophiles” and which year?

Schmidt-Nielsen, 1902

Who was the first to demonstrate that pure cultures of bacteria can grow at 0 C? When?

Foster, 1887

Year in history of observation of foodborne pathogens

• First diagnosis of Bovine Spongiform Encephalopathy (BSE) in cattle in UK

1986

Use of heat in the commercial setting started around

1867-1868

Autoclaving of food was attempted in which year

1853

Year in history of observation of foodborne pathogens

• First report of streptococci food poisoning (Linden, Turner, Thom)

1926

When did we start using ozone as method of preservation?

1882

Steam sterilization was attempted in which year

1843

Heat preservation method that came into general use in 1950

D value concept

When did we start using nisin (antibiotic) as method of preservation?

1954

Who conducted the first bacteriological study of canning in 1895?

Russell

What did Nicolas Appert patent in 1810?

Thermal canning

What type of microorganism can be found in canned goods?

• Endospore-forming

• Anaerobic

• Thermophiles

Year in history of observation of foodborne pathogens

• First association of staphylococci with food poisoning (T. denys)

1894

Year in history of observation of foodborne pathogens

• Sausage poisoning (probably botulism)

1820

Year in history of observation of foodborne pathogens

• Recognition of paralytic shellfish poisoning

1937

Nicolas Appert patented thermal canning in which year

1810

What year was irradiation approved for pathogen control in meat and poultry?

1990

When did we start using radiation as method of preservation?

1943

Year in history of observation of foodborne pathogens

• Aflatoxin in Aspergillus flavus

1960

What year did the mad cow disease crisis in UK occur?

1990

Use of irradiation on eggs and vegetables were approved on year _

2000

_ patented thermal canning in 1810

Nicolas Appert

When did HACCP (Hazard Analysis Critical Control Point) become a requirement in US?

1990

First report of mad cow disease in US occurred in year _

2000

What year did they start establishing food regulations (on bioterrorism, pathogen spread preventative control)?

2000

Russell conducted the first bacteriological study of canning in which year

1895

Russell conducted the _ in 1895

first bacteriological study of canning

Required by government to ensure your product is safe and of quality

Hazard Analysis Critical Control Point (HACCP) plan