Estudos Sobre Carotenóides Com Atividade De Provitamina "A" Em Cultivares De Mandioca (Manihot Esculentacrantz) Em Ecossistema De Terra Firme De Manaus, Amazonas, Brasil.

Abstract

Competition experiments were carried out between different cultivars of manioc (Manihot esculentaCrantz) in the terra firme ecosystem (Manaus, Amazonas, Brazil), with the productivity and pro-vitamin A carotene content. Roots from sevem cultivars of yellow manioc were selected for the identification and quantification of carotenes with vitamin A activity, according to the method described by Rodriguez. Pro-vitamin A loss due to processing and storage of the flour was also determined. The presence of three b - carotene isomers was noted (13 - cis - β - carotene, all trans β - carotene and 9 - cis - β - carotene). The amount of vitamin A present in the roots varied from 4.4 to 18.8 retinol equivalents. The loss of vitamin A due to processing was high, ranging from 25.3 to 40.0 %. The storage of the roots for six months in transparent plastic bags at room temperature and exposure to the sun, resulted in a total degradation of the carotenoids. The results allow one to conclude that three cultivars (IM 232; IM 104 and BGM 021) containt the highest pro-vitamin A content.