A taste of science

Students learn how chemistry and physics contribute to the taste and aroma of fermented foods

Students got a literal taste of their own concoctions during a recent lab session of Flavor Molecules of Food Fermentation: Exploration and Inquiry (ES 24). They explored different concepts from science that play a role in the culinary arts, from everyday cooking techniques to haute cuisine.

By using different fermentation techniques, students researched microbial communities, characterization, metabolism, and chemical properties of small molecules that contribute to the taste and aroma in fermented foods. 

Instructor Pia Sorensen (center) works with Emily Soice, a biology and environmental engineering student from MIT, and Maximillian Prager, A.B. '19, an integrative biology concentrator, to test the flavors of the inoculated plums. (Photo by Manasa Joshyam)

“My favorite project this semester was when we made different kinds of yogurts and then had a sensory scientist come and walk us through a flavor panel, so we learned to describe different flavors. Using gas chromatography mass spectrometry (GC/MS), we then tried to look at the flavor molecules of these yogurt flavors and how they differed. Now, we are submitting them to sequencing to figure out what microbes are present and how all of this ties back to the original flavor,” said Pia Sorensen, the course’s designer/instructor and Senior Preceptor in Chemical Engineering and Applied Materials at the Harvard John A. Paulson School of Engineering and Applied Sciences.

The hands-on, experimental class, which is held in a specially designed cooking laboratory, is open to students from all backgrounds, and encourages a collaborative working environment that utilizes each of the students’ skills.

“It is also one of the few rare chemistry classes where we actually get to eat things,” said Erin Kim, A.B. ’19, a molecular and cellular biology concentrator.

Erin Kim (left), A.B. ’19, a molecular and cellular biology concentrator, and Jess Kim, A.B. ’19, a chemistry concentrator, explore the science behind fermented foods. (Photo by Manasa Joshyam)

Jess Kim, A.B. ’19, a chemistry concentrator, was working with teammates to make amazake (a Japanese drink typically made from fermented rice) using different foods.

“We are interested in utilizing food waste,” she said. “A lot of food wasted is usually very high in starch, like bread, so we are trying to see what type of flavors and effect we can get by adding koji to these foods.”

Lin Ni, A.B. ’19, a neurobiology and computer science concentrator, and her teammates were working on a project that combines food with sound.

“Research has shown that different frequencies can affect bacterial growth, so we are making yogurt and mead, which will later be placed in sound proof containers with tuners at different frequencies, so we can understand how it affects growth,” she said.

(From left) Jessica Tsang, A.B. '20, a human evolutionary biology concentrator, Lin Ni, A.B. ’19, a neurobiology and computer science concentrator, and Celina Qi, A.B. '19, a neurobiology concentrator, work on making mead and yogurt that they wlil place into a sound-proof containers. (Photo by Manasa Joshyam)

The course, which aims to provide students with experience in the chemistry of flavor molecules, physiology of flavor, and experimental design process while building teamwork and communication skills, also offers an opportunity to engage with visiting speakers and explore potential research projects.

“Ultimately, the goal is to learn how to ask questions and keep going deeper and deeper until we can ask a question that really adds to the field of research,” said Sorensen.