Student Stories: Purple eggs, pickling process fascinated her

March 30, 2011

University Park, Pa. -- Dr. Seuss' strange little creature, Sam-I-Am, long ago made green eggs famous. Now, Penn State College of Agricultural Sciences student Angela Richard is drawing the public's attention to purple eggs. Pickled eggs -- with their notable color -- were the focus of her undergraduate research.

By analyzing how the pickling process safely removes pathogens from eggs, she made sure that these snacks could be enjoyed harmlessly by anyone who craves them.

Richard, now a graduate student in the college's Food Science program, earned her bachelor's degree in food science from Penn State in December 2008. During the last semester of her senior year, she began a project that still affects her life. A local food company in Lancaster, Pa., wanted to change its pickled eggs packaging from glass to plastic.

"My job was to make sure the eggs still would be safe in this form of packaging," said Richard. So she began a research project to find out.

Because the FDA prohibited the company from moving forward with this change before the safety was determined, Richard had to work as efficiently as possible. Along with two fellow students, Richard set out to replicate the company's manufacturing methods.

"I had to go to the plant and learn the entire process before I could start," Richard said.

The multi-step process of making pickled eggs begins when the eggs are hard boiled and peeled. After that, they are put in a strong pickling solution for 24 hours to remove any harmful bacteria that might be present. Then the eggs are placed into a less acidic solution to create a better and milder taste for consumers.

Finally, they are sealed in the containers and are ready for customers to enjoy.

After learning the process, Richard began her research. "I tried to replicate the process as best as I could here at Penn State," she said. Richard used the same brine solution the company employed to pickle eggs along with the containers in which the company packaged them.

"Even the number of eggs per jar was kept exactly the same so we wouldn't have to do any scaling down," she said.

Richard essentially set up her own pickling plant in a lab at Penn State. To test if the eggs would be safe in the new plastic packaging, she first inoculated them with a cocktail of five different pathogens, including E. coli and Salmonella, to investigate whether levels of the pathogens would be decreased to a safe level throughout the pickling and packaging process.

"The amounts of pathogens that I inoculated into the eggs represented a worst-case scenario," she said. "If they were contaminated naturally, the levels wouldn't be so high."

After inoculating both the eggs and the jars separately and putting them into the pickling brine, Richard found that the acidic environment did in fact reduce the levels of pathogens. The process that the company used, therefore, would provide customers with a safe product in plastic containers.

While the research itself lasted about a year, Richard still is not done informing the public of her findings. Last summer she presented her research at a conference, and her study is now submitted for a publication.

Presently, Richard is developing a food-safety program for employees working in delicatessens. But her pickled eggs study has had lasting influence on her.

"After doing my research, I couldn't eat, smell or even look at eggs for a really long time," said Richard.


  • Angela Richard with a research poster about pickled eggs.

    IMAGE: Penn State

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Last Updated March 30, 2011