Innovation and multidisciplinarity are the way to accelerate improvements in education, as well as the search for contextualized content. The multidisciplinarity between chemistry and Biology, allows to explore various contents, one of them is the environment. Works that offer alternatives to simpler experiments are of great help professors. In this context, this study suggests a didactic sequence using easily accessible materials to address chemical and Microbiological concepts of soil. The proposal is aimed at high school students and early undergraduate students. The contents were: hydrogen potentials (pH), mixture separation methods, soil liquid and gas phases and soil microbial population extraction involving bacterial DNA. Thus, the work shows a low cost alternative for the teaching of concepts related to soil, being a contextualized, multidisciplinary, dynamic and attractive proposal.

O objetivo do presente trabalho foi caracterizar a composição centesimal e quantificar os ácidos graxos com ênfase em ácidos graxos trans em chocolates normal e dietéticos de cinco grandes marcas. As amostras foram adquiridas em diferentes supermercados na região de Maringá. As marcas foram nomeadas por letras, sendo que para cada marca, foram analisados cinco lotes, com três unidades de chocolate por lote e as análises foram realizadas em triplicatas. Observou-se que os chocolates diets apresentaram maiores teores de lipídios que os chocolates normais das mesmas marcas. Os principais ácidos graxos observados foram os ácidos graxos saturados (SFA), ácido mirístico (14:0), ácido palmítico (16:0) e ácido esteárico (18:0). Entre os ácidos graxos monoinsaturados (AGMI), ácidos graxos poli-insaturados (AGPI) e ácidos graxos trans, o ácido oleico (18:1 n-9), ácido linoleico (18:2 n-6), ácido e elaídico (18:1-9t) predominaram. O conteúdo de ácidos graxos trans encontrado nas amostras analisadas foram inferiores e/ou iguais aos limites estabelecidos pela regulamentação brasileira.

The objective of the present study was to characterize the centesimal composition and quantify fatty acids in regular and diet chocolate brands with emphasis on trans fatty acids. Regular and diet dark chocolate samples from the major brands analyzed were purchased from different local supermarkets in the city of Maringá. The brands were labeled with letters and five lots of each brand with three chocolate units per lot were analyzed in triplicate. We observed that the diet chocolates from the same brands presented larger lipid contents. The main fatty acids observed were saturated fatty acids (SFA), myristic acid (14:0), palmitic acid (16:0), and estearic acid (18:0). Among the monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) and trans fatty acids, oleic acid (18:1n-9), linoleic acid (18:2n-6), and elaidic acid (18:1-9t) predominated. The trans fatty acid contents found in the analyzed samples were lower than and/or in accordance with the limits proposed by the Brazilian regulation.