Abstract:

In developing 21st Century learning skills, at Panama’s Instituto Bilingüe Andrés Bello we have established a program called “Integrated Learning Scenarios” (ILS) in which, for one month each schoolyear, classrooms are adapted to study a specific topic of interest proposed by the students themselves. This gives rise to a host of activities, research projects, and workshops, which integrate various subjects around the chosen area of interest.

Here we recount an ILS experience with an 11th grade Bachelor of Science class on the topic of nutritional content of commercially available pastuerized milk in comparison to that of fresh, whole non-pastuerized milk. In particular, students wondered whether pasteurization affects the levels of various nutrients present in milk.

This ILS required us to improvise a laboratory in the classroom, in order to verify the presence of proteins, lipids, fats, and lactose in the milk, as well as determine its acidity. Biuret Reagent and Sudan iii were used to detect proteins and lipids, respectively. Fat levels were measured via centrifugation. Meanwhile, a similar experience was conducted at another school, the IPT Agropecuario Gil Betegón, using raw whole milk instead of pasteurized milk. Subsequently, a virtual conference was held where students from both schools were able to compare and discuss their results.

Thus, they confirmed that the changes milk suffers as a result of pasteurization and/or storage can produce changes in its pH level. The also verified that acidity can be affected by certain adulterations. In particular, watering and neutralization lower pH considerably, whereas skimming and serum adition also change it.

In addition to conducting the lab tests, students designed a web page where their results were published, and a scientific magazine was created to foster in-class experiments. Students furthermore learned to represent their results in graphs, which were exhibited in the school’s auditorium for the benefit of the entire school community.

With this project we succeeded in placing the students at the center of the learning process, beginning with their interests, and preparing them in a holistic manner for the scientific and social challenges ahead of them.

Keywords:

Biuret, pH.