Wilton Soares Cardoso

Variabilidade de genótipos de milho quanto à composição de carotenoides nos grãos

O objetivo deste trabalho foi caracterizar e avaliar a variabilidade quanto ao teor e perfil de carotenoides nos graos de 134 genotipos de milho (Zea mays), com vistas a utilizacao em programas de biofortificacao. Os materiais foram provenientes dos campos experimentais e do Banco Ativo de Germoplasma da Embrapa Milho e Sorgo, Sete Lagoas, MG. Sao cultivares e hibridos comerciais, linhagens-elite e outros acessos escolhidos com base na coloracao amarelo-alaranjada do endosperma. A quantificacao do teor de carotenoides totais, carotenos e xantofilas mono-hidroxilada e di-hidroxilada dos graos foi realizada por metodo cromatografico-espectrofotometrico. As medias encontradas nos graos foram 22,34µ gg-1 de carotenoides totais, 2,55µ gg-1 de carotenos, 3,86µ gg-1 de xantofilas mono-hidroxiladas e 15,93µ gg-1 de xantofilas di-hidroxiladas. Os genotipos foram agrupados em 18 grupos pelo metodo de Tocher. O germoplasma da Embrapa possui potencial para ser usado em programas de desenvolvimento de linhagens de milho biofortificadas, quanto ao total de carotenoides pro-vitamina A.

Color of Corn Grains and Carotenoid Profile of Importance for Human Health

The increasing on the levels of carotenoids in staple foods of broad human consumption is one of the strategies of food biofortification programs, mainly due to the importance of these compounds to human health on the prevention of vitamin A deficiency. Maize is a major staple food due to its high consumption in regions where problems of Vitamin A deficiency are of great relevance. Maize biofortification programs have made progress in determining the amounts of carotenoids in grain of thousands of accesses. This work aimed at studying the influence of the color of the grains in the profile of carotenoids in four different Brazilian genotypes. The selection of ears within the same genotype was based on a color scale, considering the lighter (lightest yellow) in one group and the most colorful (darkest orange) in another group. Significant interactions (p 0.05) between the color of the grains and the genotypes for all the variables were detected in addition to genetic variability for both groups (lightest yellow and darkest orange). The colored ears of corn showed a high level of total carotenoids (TC) and fractions in RS 535 and RS 445, and the colorful ears of genotype RS 535 showed 300% more α + β carotenes (μg·g-1) in relation to lighter of this same material. The results of this study showed the influence of genotype on the grain color and content of carotenoids, indicating that breeders have the flexibility to make selection of some genotypes based on grain color, reducing cost and time compared to laboratory methods used for the screening of genetic materials.

Influence of the moisture at harvest and drying process of the grains on the level of carotenoids in maize (Zea mays)

Maize is considered a source of carotenoids; however, these compounds are highly unstable, degraded by high temperatures, exposure to light and presence of oxygen. The objective of this work was to evaluate the influence of the moisture and type of drying applied to grains on the level of carotenoids in yellow maize. The experiment was conducted in a completely randomized design (2 × 4 factorial), two levels of initial moisture at the harvest (22 and 19%) and three types of drying (in the sun; in the shade and in a dryer) and control (no drying). The samples of grains after drying with 12% of final moisture were analyzed by concentration of total carotenoids, carotenes (α-carotene + β-carotene), monohydroxilated carotenoids (β-cryptoxanthin), and xanthophylls (lutein + zeaxanthin). Initial moisture, type of drying and the interaction between moisture versus drying influence (p≤0.05) the levels of carotenoids in grains. This is the first report about the drying conditions and harvest’s initial moisture as influence on the profile and content of carotenoids in maize grains. Based on the results, this work suggested that the harvest be carried out preferably when the grains present 22% humidity, with drying in a dryer or in shade for further use or storage.

Análise colorimetrica de açúcar mascavo e sua aceitação no mercado de viçosa-MG, Brasil

Brazil is known for its sugar cane production. Raw sugar is produced by artisanal farmers. As a result of artisanal production, raw sugar is diverse in color. The aim of this study was to analyze raw sugar color and its sensory acceptance in the market of Vicosa, Minas Gerais, Brazil. Colorimetric tests (CIELAB) were done. The results were analyzed by multivariate analysis, similarity and dissimilarity measurements and clustering techniques (GENES software). Two samples of raw sugar commercialized by Associacao Riobranquense de Produtores de Rapadura, Acucar Mascavo, Aguardente e Melado (ARPRAM), eleven samples produced of his associates and six samples from commercial brands were colorimetrically analyzed. Three representative samples of dark, semi-dark and light color were chosen to test color sensory acceptance. This assessment used a nine point hedonic scale. Of the 19 samples analyzed, 13 had visible color differences. Samples with the highest dissimilarity were from a producer and from ARPRAM, with 16.47 Euclidean distance. Samples with greatest similarity were from ARPRAM and from a commercial brand with 0.44 Euclidean distance. There was no significant difference in color sensory acceptance among the tested raw sugar samples. Colorimetric analysis confirmed a lack of color uniformity among the samples produced and marketed by ARPRAM and from the commercial brand. However, differences in color did not influence the sensory acceptance of raw sugar among consumers

Carotenoides em grãos de milho verde após a aplicação de herbicidas pós-emergentes

The objective of this work was to evaluate the efect of post-emergence herbicide application on carotenoid content in green corn grains. A completely randomized design was used, with five treatments - no application; foramsulfuron + iodosulfuron-methyl-sodium (40 g ha-1); nicosulfuron (20 g ha-1); mesotrione (120 g ha-1) and tembotrione (100 g ha-1) -, and two replicates. The grains were evaluated in terms of lutein, zeaxanthin, beta-cryptoxanthin, alpha-carotene and beta-carotene, pro-vitamin A carotenoids, total carotenoid contents, and percentage of lutein, zeaxanthin and pro-vitamin A carotenoids. Tembotrione and nicosulfuron herbicides did not cause deleterious effects on total carotenoids or fractions with pro-vitamin A activity.