Caracterização físico química de α - quitina em exoesqueletos de escarabeídeos (Strategus sp.) e aproveitamento da biomassa residual para obtenção de quitosana

Abstract

In this study, the physical-chemical structure of the exoskeleton of scarabeids of the genus Strategus sp. was characterized along the insect's chitonous body. Elytras, paws and abdomens were submitted to acid and alkaline digestions and structural chemical properties were evaluated using FTIR and XRD techniques. The polymorphic structure of the biopolymer was characterized as ɑ-chitin. The extracted chitin presented the degree of acetylation of 83.48%, 81.82%, 72.77% for elytra, paws and abdomen respectively. The X - ray diffractograms presented reflection planes at 2θ 9,2 ° (020) and 2θ 19,2 ° (110). The crystallinity indexes for elytra, paws and abdomen were 95.5%, 94.9%, 94.6%, respectively and the values obtained showed linearity with the degree of acetylation calculated for each part of the exoskeleton of the insect. The chitosan obtained by chemical derivatization showed a degree of acetylation of 38.28% which characterizes the predominance of free amine groups, making the compound behave as a strong polyelectrolyte, this characteristic allows a greater reactivity and the formation of new compounds derived from chitosan.