Abstract:

Laboratory practices are a key component in the training of chemical engineering and food science students, particularly in courses involving biological and environmental processes. However, students frequently arrive at laboratory sessions with limited familiarity with experimental procedures and process dynamics, which may reduce the effectiveness of laboratory time and hinder the understanding of complex experimental systems.

This work presents a flipped-laboratory approach based on the development of short audiovisual pre-lab resources designed to improve student preparation before attending practical sessions. These materials allow students to visualize analytical procedures, equipment operation and experimental workflows in advance. Digital resources were provided and teacher–student discussions were established using the institutional interactive platform forVirtual Learning Environment (Moodle), promoting autonomous preparation and facilitating a more effective use of laboratory sessions. The methodology follows the principles of Just-in-Time Teaching, enabling students to acquire essential procedural knowledge prior to experimental work.

The approach was implemented in two courses: Biochemical Engineering in the 3rd course of Chemical Engineering Degree and Characterisation and Management of Waste in the Food Industry in 4th course of Food Science and Technology Degree. Approximately forty students participated in the experience. The audiovisual resources enabled students to follow the evolution of anaerobic digestion experiments over a period of approximately 30 days. Through these materials, students observed the progressive increase in biogas pressure associated with the methanogenic phase of the digestion process. In addition, the experimental data were analysed using a simplified kinetic modelling approach based on the Modified Gompertz model, allowing students to interpret the evolution of biogas production and to connect experimental observations with the modelling of biological processes.

To evaluate the effectiveness of the intervention, diagnostic multiple-choice tests were conducted before the laboratory sessions and final assessments after completing the practical activities. The results showed a clear improvement in student performance, with average scores increasing from approximately 4–5 points to around 8–9 points. Similarly, the pass rate increased from roughly 50–60% to almost the entire group.

Overall, the proposed approach represents an innovative and transferable strategy for laboratory-based education in engineering and experimental sciences, improving student preparation, conceptual understanding of biological processes and engagement in practical learning.

Acknowledgement:
The support of the University of Castilla-La Mancha through the project “Development of Audiovisual Resources and Simulation Models for Biological Process Laboratory Practices in the Faculty of Chemical Sciences and Technologies” is gratefully acknowledged.

Keywords:

Flipped laboratory, audiovisual learning resources, anaerobic digestion, STEM Education Experiences, laboratory teaching innovation, Just-in-Time Teaching.