Food Microbiology: 26 MCQs with answers

Inner tissue

The inner tissue of healthy fish is sterile; microorganisms are mainly associated with outer slime, gills, and intestine.

Intestine

Microbial load is higher in the intestine followed by gills and outer slime.

Nicholas Appert

Nicholas Appert developed canning of meat in glass bottles in 1809, which had practical application in food preservation.

Pasteur

Pasteur demonstrated the role of microorganisms in souring of milk in 1837.

1860

Pasteur applied heat to destroy undesirable microorganisms in wine and beer in about 1860.

To maintain fish quality by reducing, killing or inactivating spoilage microorganisms

Preservation methods mainly aim at maintaining fish quality by reducing, killing or inactivating associated spoilage microorganisms.

False

Fish are not sterile; their microflora includes natural flora from water and transient flora from the environment.

Inner tissue

The inner tissue of healthy fish is sterile, meaning it does not contain any microorganisms.

Mesophilic bacteria

Fresh warm water fish typically have more mesophilic bacteria due to their habitat and temperature.

Microorganisms from handling

Transient flora in fish primarily comes from microorganisms that enter during handling and processing.

It begins to spoil

Once fish dies, the associated microorganisms begin to affect its quality, leading to spoilage.

Sumerians

The Sumerians practiced the use of salted meat and fish as a preservation method around 3000 B.C.

Athanasius Kircher

Athanasius Kircher was the first to observe decaying bodies and suggest microorganisms' role in spoilage.

Spallanzani's beef broth experiment

Lazzaro Spallanzani's experiment with beef broth demonstrated that sterilized broth remained free of microorganisms.

1809

Nicholas Appert developed the canning of meat in glass bottles in 1809, which was significant for food preservation.

To maintain quality by reducing spoilage microorganisms

The primary aim of preservation methods is to maintain fish quality by reducing or inactivating spoilage microorganisms.

Bacteria, fungi, viruses, protozoans, and parasites

Fish from polluted water can carry a variety of microorganisms, including bacteria, fungi, viruses, protozoans, and parasites.

Fish contact surfaces like crafts and gears

Transient flora include microorganisms entering the food from fish contact surfaces, air, soil, water/ice, food handlers, packaging material, and storage environment.

Mesophilic bacteria

Fresh warm water fish generally have more mesophilic bacteria than cold water fish.

A. Kircher

A Kircher, a monk, in 1658 first observed decaying substances and believed invisible worms caused spoilage, suggesting the role of microorganisms.

L. Spallanzani

L. Spallanzani in 1765 opposed spontaneous generation with his experiment using beef broth which remained sterile after boiling and sealing.

Schwann

In 1837, Schwann's experiment of passing heated air into boiling broth caused it to remain sterile, disproving spontaneous generation.

Pasteur's swan neck flask experiment

It was not until Pasteur's well planned swan neck flask experiment that the theory of spontaneous generation of life was put to rest.

Sumarians

The use of salted meat, fish, fat, dried animal skin and cereals was practiced by the Sumarians at about 3000 B.C.

1000 B.C.

Romans were known for adopting preservation techniques for meat and also use of snow for perishables including prawns at around 1000 B.C.

True

The text states that the role of microorganisms in spoilage and food poisoning was realised only after the establishment of bacteriology or microbiology as a science during the early 18th century.