Separação de carotenóides, clorofilas e flavonóides em folhas de plantas: uma abordagem simples e ecológica

Abstract

Separation of Carotenoids, Chlorophylls and Flavonoids from Plant Leaves: a simple and ecological approach - The experimental activity presented here aims to replace or supplement the traditional separation of chloroplast pigments by column chromatography, from green leaves. The new approach, using red and green leaves, leads to higher visual impact and involves simpler and greener procedures. To achieve these goals, a simple and ecofriendly procedure was developed to prepare extracts from these leaves. The chromatographic separation of this extract in a disposable syringe containing potato starch as adsorbent allowed an excellent separation of bands with yellow, blue-green, yellow-green and red colors, which were attributed to β-carotene, xanthophylls, chlorophylls a and b and anthocyanins, respectively. This activity can be useful in higher education in practical classes designed to teach chemistry laboratory techniques and fundamentals of organic chemistry. The challenges associated with the additional separation of anthocyanins, hydrophilic pigments, will broaden the learning outcomes of traditional activity, which separate only lipophilic pigments, and enable teachers to adopt targeted pedagogies to exercise critical thinking of the student. This activity is also suitable to primary and secondary education to stimulate young people to the chemistry and to demontrate basic concepts of chemistry.