Composição em aminoácidos e digestibilidade in vivo de proteínas do arroz nativo, espécie Oryza latifolia, da região do Pantanal, no estado de Mato Grosso do Sul

Abstract

The rice Oryza latifolia, red and small grains, is an wild specie found in different regions of the flooded areas, as to the margins of the rivers of the Pantanal sul-mato-grossense. The objective of this work was to study the proximate composition and protein quality, in the grains this rice, trhough biological assay and in vitro assay, comparing your mixture with bean. The analyzis of the proximate composition were realized according to the methods of the Instituto Adolfo Lutz, Association of Official Analytical Chemists and Van Soest & Wine, on the samples prepared with the rice and with the bean, determining the amount of ingredients to the formulation of diet used in biological assay. The amino acid composition was performed according to Henrikson and Meredith, on a Pico Tag amino acid analyzer (Waters), meeting as the most limiting amino acids, the methionine+cistyne, with chemical score of the 0.32. Already the amino acids in more concentration were the combination of the phenylalanine+tyrosine, with chemical score of the 3.01, if compared with FAO´s reference standards. It presented 9.83% protein contents, concentration more elevated than the white rice (O. sativa) usually consumed, aproximately 7.2%. With the obtained results in the proximate and amino acid composition, test rice, rice+bean combination and casein formulations were prepared to be isoprotein and isocaloric diets in the biological assay . The assay was conducted with 31 Wistar male rats, during 29 days, divided in 4 groups (Aproteic, Standard, Test 1 and Test 2). After the biological assay were determined to the Standard (casein), Test 1 (rice) and Test 2 (rice and bean) groups, the Biological Value (respectively, 95.47%, 96.15% and 97.65%), True Digestibility (respectively , 92.18%, 65.53% and 81.33%), Nitrogen Balance (respectively , 3.30, 1.67 and 1.52), Net Protein Ratio (respectively , 3.58, 2.57 and 2.27), Feed Efficiency Ratio (respectively , 56.00%, 30.98% and 29.57%) and Protein Efficiency Ratio (respectively , 3.00, 1.52 and 1.14). Showed biological value next between the groups Casein (95.47%), Test 1 ( 96.15%) and Test 2 ( 97,65%) and what the mixture in the rice O. latifolia and bean presented the best digestibility (81.33%) related the digestibility of the mixture of the white rice O. sativa and bean (57.67%). So, the nutritional quality of the wild rice in specie O. latifolia observed indicate that the rice will can to go source supplementary in diets of the population and as source of information about the nutricional rich of the rice.