Date of Award
Chemistry and Biochemistry
Communicating the beauty and complexity of biochemistry to students in a large classroom during the pandemic: what a challenge! We undertook a novel endeavor in the Department of Chemistry and Biochemistry by introducing a mandatory kitchen chemistry experiment in a lecture course. Milk, the epitome of our identity as mammals, also contains all of the major biochemical macromolecules studied in Biochemistry I. Further, the making of yogurt invokes physical processes that are the major processes and molecular forces that dominate the content of the course. Here, we report the results of massive parallel experiment conducted in the kitchens of the students enrolled in a large lecture course in our department at the University of Mississippi. Students prepared yogurt from kits that we supplied. Our hypotheses were: 1) lactose was required for curd formation, so lactose free milk would not form curd; 2) Only casein containing milk would form curds, so soy milk would not form curd; and 3) Fermentation by the bacterial cultures would cause the yogurt to be acidic relative to the milk from which it was made. The two measurable quantities were the pH of the solution and an informal viscosity measurement performed by dropping a stainless-steel ball through a standardized column on yogurt (BB drop test). Thus, students were assigned a control milk and a test milk of five types: Whole, 2%, Fat Free, Lactose Free, and Soy. An online form was developed for students to submit all relevant aspects of their “lab report. A total of 127 complete reports were submitted. An analysis was done to determine the relevance of the recorded information, resulting in the deletion of nine entries. Formats of entries were standardized. Results showed that 1) Lactose free milk formed curds. 2) Soy milk formed a very thin curd, but thickened. 3) All milks were acidified after incubation in the bacterial starter culture. Suggestions for revision of protocol and reporting of the experiment are provided.
King, Ashley, "Bringing Biochemistry Home: Transforming Milk into Yogurt" (2021). Honors Theses. 1692.
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