Extração e uso de corantes vegetais da Amazônia no tingimento do couro de Matrinxã (Brycon amazonicu Spix & Agassiz, 1819)

Abstract

The use of natural dyes starting from residues of wood, peels of fruits, seeds, flowers and other materials that preserve the Amazon flora and don't cause the human health and to the environment damages can be used as alternative for staining of leather of fish source from skins that previously were discarded. The objective was to evaluate the vegetables dyes in the staining the hide of the matrinxã (Brycon amazonicus) leather. Peels of: Amazon fruits such as: rambutã, mangostão, bacuripari, murici, cashew tree, tucumã and tangerine, cupuaçu and urucum seeds, self-fruits of patauá and grounds of açaí, leaves of crajiru, flowers of cacauí, inflorescence of banana tree and açaí palm, were evaluated as for to the humidity, antocianins, carotenoids, phenolics contents, soluble pigments in water and pH. Crajiru and cacauí presented higher concentration of the antocianina pigment, hydrosoluble and adaptation to the pH (acid) of the staining process. Thus, these two products were selected as coloring source for the skin of matrinxã fish to grade at leather. Dehydrated crajiru and cacauí samples at 6 and 8%, respectively at the 5, 10 and 15% ratios to the weight of the leather were used in the coloring of the matrinxã leather. After the staining and finishing, the leather samples were evaluated by scanning electronic microscopy, brightness resistance and washability test. Crajiru stain presented higher resistance to the action of the light and water. Crajiru presented the coloration changing from the red-purple to the wine and the cacauí of the light and dark lilac, taking into consideration to the ratio of staining. Despite of there be no statistics significance among the of 10 and 15% contents this last resulted at more intense coloration. The conditions and proportions of both were shown appropriate. Their uses will depend of the tonality, coloration and availability of the source of coloring wished. Therefore, crajiru and the cacauí can be excellent sources of natural on the staining of leather matrinxã.