Science and Our Food Supply: Investigating Food Safety from Farm to Table

Time to review and summarize. 

REVIEW

SUMMARY

Pasteurization is the process of destroying 

microorganisms that can cause disease. This 

is usually done by applying heat to a food. 

In order to determine which mystery juice 

is pasteurized, both must be plated on agar 

dishes and observed. The unpasteurized juice 

should have a greater number of organisms 

because it was freshly squeezed and may be 

contaminated from handling, etc. It hasn’t 

been heated to destroy bacteria. 

EXTENSIONS

• 

Answer the question raised in the video by Dr. Sizer, “How can 

you pasteurize an egg in the shell without cooking it?” 

• 

Research why some milk can be stored on the shelf and some 

milk must be refrigerated. 

• 

Research the history of pasteurization. 

• 

Write a letter to Louis Pasteur to thank him for developing the 

process of pasteurization, and tell him how important this process 

is in lowering the incidence of foodborne illness. Also explain how 

it makes foods more convenient for us today. 

• 

Research how people safely stored food prior to pasteurization, 

and choose which method you think was best — give reasons, 

specific details, anecdotes, and examples. 

• 

Relate your pathogen to this lab and record the information in 

your food safety portfolio. 

UP NEXT

Aside from pasteurization, what other process 

destroys harmful bacteria in foods? (Clue: It has to 

do with the pressure created by two 5-ton elephants 

balanced on a dime.) You’ll discover and  

explore this process in the next activity.