Uso do extrato de jenipapo como indicador ácido-base: uma proposta de atividade experimental no ensino de Química

Abstract

This undergraduate thesis proposes the use of the extract from the fruit Genipa americana L. (jenipapo) as a low-cost acid–base indicator, offering an experimental activity to support Chemistry teaching. Experimentation is a fundamental tool, as it enables students to experience chemical phenomena in a practical way, fostering investigative thinking and the construction of scientific knowledge. The main objective was to investigate and characterize the potential of the extract, which is rich in geniposide, to visually illustrate the chemical nature of solutions. The methodology employed was qualitative and based on bibliographic research, supported by the analysis of scientific articles on natural indicators, experimentation, and the chemical composition of geniposide. The expected results indicate that the pigment Genipin Blue, formed under alkaline conditions, exhibits a clear chromatic transition ranging from red/purple in strongly acidic media to dark blue/black in alkaline media. This effectiveness aligns with Green Chemistry principles, as the extract uses water as a solvent and presents low toxicity and easy biodegradability. From a pedagogical perspective, the proposal stands out for its inclusive value and its contribution to Meaningful Learning, since the low cost of jenipapo reduces socioeconomic barriers and its cultural familiarity functions as a strong advance organizer. It is concluded that jenipapo extract is a sustainable and contextualized alternative that contributes to the democratization of experimentation in Chemistry education.